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Background. Pulmonary complications cause signicant morbidity and mortality in patients with idiopathic inammatory myopathies
(IIMs).
Objectives. To describe the frequency and spectrum of pulmonary complications in patients with IIMs in South Africa (SA).
Methods. A retrospective records review of adult patients with IIMs or clinically amyopathic dermatomyositis (CADM) presenting with
respiratory complaints at a tertiary care facility in SA was performed. Clinical features, results of laboratory and pulmonary function tests
(PFTs), radiological ndings and treatment were recorded.
Results. Pulmonary complications were documented in 66 patients. Most patients (n=41; 62.1%) had dermatomyositis, 14 (21.2%) had
polymyositis, and 3 (4.5%) had CADM. ere were 8 patients with overlap syndromes. Dyspnoea and a dry cough were the most common
presenting symptoms, in 52 (78.8%) and 36 (54.5%) patients, respectively. Bibasal crackles were noted in 38 patients (57.6%). Interstitial
lung disease (ILD), followed by infection and pulmonary hypertension (PH), were documented in 46 (69.7%), 16 (24.2%) and 9 (13.6%)
patients, respectively. Nine patients had microbiologically conrmed pulmonary tuberculosis. Patients who were anti-Jo1 antibody positive
(n=16) had higher levels of acute inammatory markers and muscle enzymes compared with the rest of the patients (p<0.0001). Dyspnoea
and bibasal crackles were associated with signicantly lower baseline and 12-month lung function parameters. Nonspecic interstitial
pneumonia was the most common radiological pattern of ILD, present in 25 (62.5%) of the patients with ILD.
Conclusion. ILD was the most prevalent complication in this study of SA patients with IIMs. Pulmonary infections and PH were also
signicant contributors to morbidity. e presence of dyspnoea and crackles was predictive of lower baseline PFTs in this population.
Keywords. Interstitial lung disease, idiopathic inammatory myopathies, autoimmune diseases, dermatomyositis, polymyositis.
Afr J Thoracic Crit Care Med 2024;30(3):e1663. https://doi.org/10.7196/AJTCCM.2024.v30i3.1663
Idiopathic inflammatory myopathies (IIMs) are a group of rare
systemic autoimmune rheumatic disorders (SARDs) characterised
by muscle inammation, presenting clinically as proximal muscle
weakness with variable extramuscular manifestations, especially skin
involvement. e estimated prevalence of IIMs is 1 - 2 cases per 100
000 in the general population. IIM was initially classied by Bohan
and Peter in 1975[1] into the two major variants of dermatomyositis
(DM) and polymyositis (PM), but several other variants under the
broad group of IIMs were described later. ese include inclusion
body myositis, the antisynthetase syndrome and clinically amyopathic
dermatomyositis (CADM).
Pulmonary complications are reported to occur in 20 - 75% of patients
with IIMs, are oen associated with clinically signicant morbidity and
sometimes cause death. ey range from acute infections, aspiration
pneumonia, respiratory muscle weakness, interstitial lung disease
(ILD), pneumomediastinum and pulmonary hypertension (PH) to
primary lung malignancies.[2-4] Of these, ILD is oen the most frequent
chronic complication, documented in 27.9% of IIM patients in a recent
study from a tertiary hospital in Durban, South Africa (SA).[5] Moreover,
ILD in IIM is oen associated with poor outcomes, with higher rates
of morbidity and mortality than IIM without ILD.[6,7] Specic clinical
phenotypes and autoantibody proles of IIM that are associated with
Pulmonary manifestations of the idiopathic inammatory
myopathies in a South African population
T Hes,1 MB ChB, FCP (SA), MMed (Int Med) ; M Wong,2 MB BCh, FCP (SA), FCCP, FRCP (Lond);
M Tikly,2 FRCP, PhD; N Govind,2 MB BCh, MMed (Int Med), Cert Rheumatology (SA), PhD
1 Department of Medicine, Chris Hani Baragwanath Academic Hospital, Johannesburg, South Africa
2 Department of Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
Corresponding author: T Hes (tam.hes@gmail.com)
Study synopsis
What the study adds.Pulmonary complications, including interstitial lung disease (ILD) and infections, are signicant contributors to
morbidity and mortality in patients with idiopathic inammatory myopathies (IIMs). ere is very little research currently available to
describe the spectrum of pulmonary manifestations in these patients in an African setting, a lack that this study aimed to address.
Implications of the ndings.ILD was the most common pulmonary complication in patients with IIMs in this cohort. Signs and symptoms
of ILD may be present before symptoms of myositis, and dyspnoea and a dry cough were shown to be predictive of reduced lung volumes.
Patients with IIMs on immunosuppressive therapy in our setting are at high risk of infection, particularly tuberculosis.
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ILD have been identied. Anti-melanoma dierentiation-associated
protein 5 (MDA5) antibodies are associated with rapidly progressive
ILD and sometimes malignancy, and anti-aminoacyl-tRNA synthetase
(ARS) antibodies with fever, Raynaud’s phenomenon, mechanic’s
hands and ILD.[8-10] Measurement of myositis-specific antibodies
(MSAs) allows for better risk stratication and prognostication and
early therapeutic intervention in ILD.
Published literature on the frequency and spectrum of pulmonary
complications of IIMs in Africa is sparse. The present study was
undertaken to describe the demographics of patients with IIMs
attending a tertiary care centre in SA, together with clinical features,
laboratory results and pulmonary involvement.
Methods
A retrospective records review of adult patients with IIMs or CADM
presenting with respiratory complaints to a tertiary care facility in SA
between 1 January 2003 and 31 December 2019 was performed. Atotal
of 77 patient les were identied in the respiratory clinic records, but
11 patients were excluded from the study owing to lack of evidence
of respiratory complications. All patients fullled the Bohan and Peter
criteria for IIM[1] or the Sontheimer classication criteria for CADM[11]
and were ≥18 years old at symptom onset. Patients dened as having
overlap myositis fullled the classication for IIM and had features of
another SARD, i.e. scleroderma, rheumatoid arthritis (RA) or systemic
lupus erythematosus (SLE). e study was approved by the Human
Research Ethics Committee of the University of the Witwatersrand (ref.
no. M200755).
Data extracted from case records were patient demographics,
respiratory signs and symptoms, laboratory results, results of pulmonary
function tests (PFTs), and chest radiograph (CXR) and high-resolution
computed tomography (HRCT) ndings. Laboratory data included a
baseline full blood count, erythrocyte sedimentation rate, C-reactive
protein (CRP), aldolase, creatine kinase (CK) and aspartate transaminase
(AST) levels, and HIV serology, antinuclear antibody (ANA) and anti-
Jo1 antibody test results. Sputum microbiological and cytological
ndings and lung histological ndings were documented in cases where
infection or malignancy was suspected. PFTs that were documented
at baseline and subsequent follow-up visits were the percentage of the
predicted forced expiratory volume in the 1st second (FEV1%pred),
forced vital capacity (FVC%pred), total lung capacity (TLC%pred),
residual volume (RV%pred) and lung diusion capacity for carbon
monoxide (DLCO%pred), using the ird National Health and Nutrition
Examination Survey (NHANES III)[12] as reference criteria with a 10%
correction for races other than white.
Pulmonary artery systolic pressure, as estimated using tricuspid valve
regurgitant velocity, and le ventricular ejection fraction were measured
using transthoracic echocardiography. PH was dened as an estimated
right ventricular systolic pressure >35 mmHg.[13]
Diagnosis of specific pulmonary complications was based on a
combination of clinical features, imaging changes (CXR and HRCT
ndings), sputum results, PFT results, echocardiography, and rarely
lung histology. HRCT ILD patterns were determined by a diagnostic
radiologist and classified as usual interstitial pneumonia (UIP),
nonspecific interstitial pneumonia (NSIP), organising pneumonia
(OP), diuse alveolar damage or non-ILD changes, using characteristic
imaging patterns.[14]
Statistical analysis
Descriptive statistics for continuous variables were expressed as either
means (standard deviation (SD)) or medians (interquartile range),
depending on whether the data were normally distributed or skewed.
e two-sample independent t-test or Mann-Whitney test was used
to compare normally distributed or skewed continuous variables,
respectively. In the case of categorical variables, Pearson’s χ2 test or
a two-tailed Fisher’s exact test (for small sample size) was applied for
frequency comparisons between groups. Statistical signicance was
set at p<0.05.
Results
Of the 77 patients with IIMs referred to the respiratory clinic for
assessment, 66 had conrmed pulmonary complications (Table1).
Eleven patients with no evidence of respiratory involvement were
excluded from the study. Most of the patients (n=54; 81.8%) were
female, 14 (21.2%) had PM, 41 (62.1%) had DM, 3 (4.5%) had
CADM, and 8 (12.1%) had overlap myositis (OM). Mean (SD) age
at diagnosis and follow-up duration were 40.8 (14.1) years and
6.2 (6.0) years, respectively. Compared with the group with DM/
CADM/OM (group 2), patients with PM (group 1) were signicantly
older at diagnosis (mean 48.9 v. 38.4 years, respectively; p=0.01).
Of 55 patients in whom the sequence of muscle and respiratory
symptoms was recorded, in most (n=33; 60.0%) muscle symptoms
preceded respiratory symptoms, in 14 (25.5%) respiratory symptoms
preceded muscle symptoms, and in 8 (14.5%) muscle and respiratory
symptoms occurred concurrently.
Muscle weakness was present in 54 patients (81.8%) at
presentation, in all the group 1 patients but only 39 (75.0%) of the
group 2 patients (p=0.04). Gottron’s papules/sign was the most
common dermatological feature in group 2. The most frequent
clinical pulmonary features were dyspnoea (n=52 patients; 78.8%),
a dry cough (n=36; 54.5%) and basal crackles (n=38; 57.6%). ILD
and infections accounted for most pulmonary complications, in 46
(69.7%) and 16 (24.2%) patients, respectively. ere were 19 incidents
of pulmonary infection in 16patients, with 3 patients presenting with
two episodes of infection. Microbiologically conrmed pulmonary
TB (PTB) was documented in 9 patients, of whom only 1 had HIV co-
infection. Two patients had respiratory muscle weakness. Lung biopsy
was performed in 5patients, with histopathological examination
showing OP in 3 and primary lung malignancy in 2. Baseline mean
CRP, white cell count (WCC) and CK were signicantly higher in
group 1 than in group 2 (p=0.049, p=0.04 and p=0.002, respectively).
ANA was positive in 29/57 (51.1%) patients, anti-Jo1 in 16/47 (34.0%)
and anti-Ro in 6/25 (24.0%).
e most common HRCT ILD patterns were NSIP (n=25/46;
54.3%) and UIP (n=15/46; 32.6%); the rest of the patients had
OP (n=3/46; 6.5%), bronchiolitis obliterans (n=1/46; 2.2%) and
unspecied ILD (n=2/46; 4.3%). ere were no signicant dierences
in ILD patterns between group 1 and group 2. Specific HRCT
abnormalities in the 46 patients diagnosed with ILD were ground-
glass attenuation in 27 (58.7%), honeycombing in 21 (45.7%) and
traction bronchiectasis in 18 (39.1%).
PFTs in the 40 ILD patients with either NSIP (n=25) or UIP
(n=15) showed that the overall baseline mean (SD) FEV1%pred was
73.0 (21.3), FVC%pred 72.5 (22.1), RV%pred 80.9 (25.7), TLC%pred
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69.7 (19.5), DLCO%pred 62.8 (23.2) and FEV1/FVC ratio 73.2
(24.9). Other than patients with UIP being significantly older
than those with NSIP (mean (SD) 46.8 (14.1) years v. 37.6 (11.5)
years, respectively; p=0.03) and having a higher baseline CRP
(51.1 (61.4) v. 16.5 (17.7) mg/L, respectively; p=0.04), there were
no significant differences in clinical characteristics or baseline
PFT results between patients with UIP and NSIP.
As shown in Table2 and Fig.1, in the 40 patients with either
UIP or NSIP, dyspnoea was associated with significantly lower
mean baseline FEV1%pred, FVC%pred and DLCO%pred (p=0.01
for all) and TLC%pred (p=0.02) compared with patients
without dyspnoea. Similarly, patients reporting a dry cough had
significantly lower baseline mean FEV1%pred, FVC%pred and
DLCO%pred (p=0.02, 0.048 and 0.003, respectively) compared
with those without a cough (Fig.2). Audible bibasal crackles were
associated with significantly lower RV%pred and DLCO%pred
(p=0.02 and p=0.0005, respectively) (Fig.3). In addition, bibasal
crackles were more common in patients with UIP than in those
with NSIP (odds ratio (95% confidence interval) 5.1 (1.15 - 22.6);
p=0.03).
Fifteen of 16 patients who tested positive for anti-Jo1 antibodies
had ILD, and most (n=10) had PM. Anti-Jo1-positive patients
had significantly higher mean baseline CRP, WCC, CK, aldolase
and AST (Table3) and a lower mean 12-month DLCO%pred.
Thirteen of the 66 patients overall (19.7%), but only 3 of the
46patients with ILD (6.5%), were lost to follow-up at 12 months.
Mortality data were only available for 1 patient; however, 53
patients were known to be alive at the time of the final data
Table1. Baseline characteristics of patients with IIMs with pulmonary manifestations
Variabl e
All patients
(N=66), n (%)*
PM (group 1)
(n=14), n (%)*
DM/CADM/OM (group 2)
(n=52), n (%)* p-value
Age (years), mean (SD) 40.8 (14.4) 48.9 (12.3) 38.4 (14.2) 0.01
Female 54 (81.8) 11 (78.6) 43 (82.7) NS
Current/ever smoker 7/62 (11.3) 3/14 (21.4) 4/48 (8.3) NS
Sequence of symptoms
Muscle rst 33/55 (60.0) 10/12 (83.3) 23/43 (53.5) NS
Respiratory rst 14/55 (25.5) 1/12 (8.3) 13/43 (30.2) NS
Simultaneous 8/55 (14.5) 1/12 (8.3) 5/43 (11.6) NS
Myalgia 43 (65.1) 14 (100) 29 (55.8) 0.001
Muscle weakness 54 (81.8) 14 (100) 39 (75.0) 0.04
Heliotrope rash 13 (19.7) 0 13 (25.5) -
‘V’ sign 12 (18.2) 0 12 (23.5) -
Shawl sign 10 (15.2) 0 10 (19.6) -
Gottron’s papules 35 (53.0) 0 35 (68.6) -
Mechanic’s hands 10 (15.2) 0 10 (19.6) -
Dyspnoea 52 (78.8) 14 (100) 38 (73.1) NS
Dry cough 36 (54.5) 8 (57.1) 28 (53.8) NS
Basal crackles 38 (57.6) 10 (71.4) 28 (53.8) NS
Finger clubbing 5/65 (7.7) 2 (14.3) 3/51 (5.9) NS
Interstitial lung disease 46 (69.7) 11 (78.6) 35 (67.3) NS
NSIP 25/46 (54.3) 5 (35.7) 20 (38.5) NS
UIP 15/46 (32.6) 4 (28.6) 11 (21.1) NS
OP 3/46 (6.5) 1 (7.1) 2 (3.8) NS
Pulmonary hypertension 9/17 (52.9) 5/5 (100) 4/12 (33.3) NS
Any infection†16 (24.2) 5 (33.3) 11 (21.6) NS
Bacterial pneumonia 10 (15.2) 3 (21.4) 7 (13.7) NS
PTB 9 (13.6) 2 (13.3) 7 (13.7) NS
Bronchogenic adenocarcinoma 2 (3.0) 0 2 (4.3) NS
CK (IU/L), mean (SD) 2 351 (3 188) 5 553.4 (4 263.6) 1 860.3 (2 957.3) 0.0004
ANA positive 29/57 (50.8) 5/13 (38.5) 24/44 (54.5) NS
Anti-Jo1 16/47 (34.0) 8/9 (88.9) 8/38 (21.1) 0.0001
Lost to follow-up 13 (19.7) 3 (20.0) 10 (19.6) NS
IIMs = idiopathic inammatory myopathies; PM = polymyositis; DM = dermatomyositis; CADM = clinically amyopathic dermatomyositis; OM = overlap myositis; SD = standard deviation;
NS = not signicant; NSIP = nonspecic interstitial pneumonia; UIP = usual interstitial pneumonia; OP = organising pneumonia; PTB = pulmonary tuberculosis; CK = creatine kinase;
ANA = antinuclear antibody.
*Except where otherwise indicated.
†Some patients had more than one type of infection.
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collection.
Discussion
Pulmonary complications are increasingly
being recognised as important causes of
morbidity and mortality in patients with
IIMs.[15] In this study of patients with IIMs
referred to a respiratory servicein SA, the
commonest pulmonary complications
wereILDand infections.
Consistent with previous studies,[15-18]
ILD was the most common pulmonary
complication in the present study,
documented in just over two-thirds of IIM
patients. Moreover, as in other studies,
NSIP was the predominant subtype of IIM-
associated ILD, followed by UIP.[2,3,16,19]
Patients with UIP in the present study were on
average a decade older than those with NSIP,
consistent with the ILD literature showing
that UIP is mainly a disease of the elderly.[20]
We observed no dierence in baseline PFT
results between the two subgroups, but UIP in
association with connective tissue disease is
known to be less responsive to corticosteroids
and immunosuppressive agents and to have a
worse prognosis than NSIP or OP.[21,22]
Our ndings underscore the importance
of clinical symptoms and signs in relation to
disease severity in IIM-associated ILD. We
found that patients with dyspnoea and/or a
dry cough had worse PFT results at baseline
than those without, specically with regard
to FEV1%pred, FVC%pred and DLCO%pred.
Bibasal crackles in the present study were
associated with signicantly lower baseline
RV%pred and DLCO%pred. Fine Velcro basal
crackles on auscultation are an early sensitive
and specific sign of IPF.[23] In the present
study, patients with UIP were five times
more likely to have basal crackles compared
with patients with NSIP. Our finding that
pulmonary symptoms were evident before
muscle symptoms in 25.5% of patients is at
odds with earlier studies, in which pulmonary
and muscle symptoms were generally found
to present simultaneously.[3,4,16] This may
in part be due to increased awareness and
recognition of ILD, especially NSIP, as the
initial manifestation of IIM, and greater
access to HRCT imaging.
ere are now several MSAs that have been
shown to be associated with specic clinical
phenotypes. Of these, anti-Jo1 (histidyl-
tRNA synthetase) antibody is the commonest
anti-tRNA synthetase antibody associated
with the antisynthetase syndrome phenotype
with variable clinical features of Raynaud’s
phenomenon, fever, inammatory arthritis,
mechanic’s hands and ILD.[8,24] Until very
recently, the anti-Jo1 antibody test was the
only MSA test available at our institution. In
the subgroup of patients who were tested for
anti-Jo1 antibodies, they were signicantly
more common in patients with PM rather
than the other clinical phenotypes and were
associated with signicantly higher baseline
CRP, total WCC, CK, aldolase and AST.
PTB was common in our study, found in
9 patients, with only one patient being co-
infected with HIV. All the patients were on
Table2. Signicant association of signs and symptoms with PFTs in patients with IIMs with either NSIP or UIP (N=40)
Variable (baseline)
Dyspnoea present
(n=32; 80.0%)
Dyspnoea absent
(n=8; 20.0%) p-value
FEV1%pred, mean (SD) 67.0 (16.3) 102.0 (27.6) 0.01
FVC%pred, mean (SD) 67.0 (16.2) 100.0 (26.7) 0.01
TLC%pred, mean (SD) 64.0 (13.7) 88.5 (22.6) 0.02
DLCO%pred, mean (SD) 58.5 (14.8) 89.0 (25.2) 0.01
Dry cough present (n=25; 62.5%) Dry cough absent (n=15; 37.5%)
FEV1%pred, mean (SD) 66.5 (19.4) 83.2 (20.8) 0.02
FVC%pred, mean (SD) 66.7 (20.8) 81.6 (21.7) 0.048
DLCO%pred, mean (SD) 54.1 (21.2) 78.2 (18.5) 0.003
Crackles present (n=29; 72.5%) Crackles absent (n=11, 27.5%)
RV%pred, mean (SD) 73.7 (23.4) 96.9 (24.4) 0.02
DLCO%pred, mean (SD) 54.8 (18.0) 84.2 (22.5) 0.0005
PFTs = pulmonary function tests; IIMs = idiopathic inammatory myopathies; NSIP = nonspecic interstitial pneumonia; UIP usual interstitial pneumonia;
FEV1%pred = percentage of the predicted forced expiratory volume in the 1st second; FVC%pred = percentage of the predicted forced vital capacity;
TLC%pred = percentage of the predicted total lung capacity; DLCO%pred = percentage of the predicted lung diusion capacity for carbon monoxide; RV%pred = percentage of the predicted residual volume.
Baseline PFT results
FEV1
% predicted
120
100
80
60
40
20
0
FVC TLC DLCO
Dyspnoea present Dyspnoea absent
Fig.1. Association of lung volumes with presence or absence of dyspnoea. (FEV1 = forced expiratory
volume in the 1st second; FVC = forced vital capacity; TLC = total lung capacity; DLCO = lung
diusion capacity for carbon monoxide; PFT = pulmonary function test.)
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corticosteroids and immunosuppressants,
emphasising the risks that the underlying
disease and drugs pose in endemic areas. In
addition to the risks of immunosuppression,
a recent study in India suggests that IIM
may be an independent risk factor for the
development of PTB, with higher rates of
infection compared with patients with SLE
on similar immunosuppressive doses.[25] More
research is needed to elucidate this risk further.
Malignancy was not a common nding in our
patients, despite the well-described association
of malignancy with DM and PM.[26] is result
may be accounted for by the younger age of
our cohort, as well as the relatively short mean
follow-up time of 6.2 years.
ere are limitations to our study. Firstly,
the retrospective study design resulted in
inconsistencies in data parameters that were
available for analysis, with missing data in
some les and no mortality data. e study was
conducted in a single centre and may therefore
not be widely applicable to the population as
a whole. In addition, some selection bias may
be present, as the clinical data were based
on case records of outpatients attending the
respiratory and/or rheumatology clinics only,
with no clinical data from neurology and
general medicine.
Another limitation is the lack of right heart
catheterisation to conrm the diagnosis of
PH in our patients. The gold standard for
the diagnosis of PH is a pulmonary artery
systolic pressure >20 mmHg at rest on right
heart catheterisation.[13] However, right heart
catheterisation is invasive and not readily
available in our setting. We therefore used
estimated pulmonary artery systolic pressure
derived from tricuspid valve regurgitant
velocity on a transthoracic echocardiogram
as a marker of PH.[13]
Laboratory assays for many myositis-
associated and myositis-specific
autoantibodies that have been shown to be
associated with ILD are not currently readily
available in SA, which limits the ability to
determine the risk of development and
progression of ILD in patients with these
autoantibody proles. Anti-Jo1 is the only
antisynthetase antibody that can currently be
tested for in our setting.
Conclusion
Respiratory complications are an important
cause of morbidity in patients with IIMs.
Table3. Signicant laboratory associations with anti-Jo1 antibody status in patients with IIMs (N=47)
Variabl e Anti-Jo1 positive (n=16) Anti-Jo1 negative (n=31) p-value
CRP (mg/L), mean (SD) 63.7 (59.9) 22.1 (37.7) 0.0006
WCC (× 109/L), mean (SD) 12.3 (4.3) 7.5 (3.0) 0.01
CK (IU/L), mean (SD) 4 948 (4 122) 935 (1 440) <0.0001
Aldolase (mU/L), mean (SD) 38.6 (36.6) 18.7 (16.0) 0.04
AST (IU/L), mean (SD) 235 (396) 69.8 (78.9) 0.03
IIMs = idiopathic inammatory myopathies; CRP = C-reactive protein; WCC = white cell count; CK = creatine kinase; AST = aspartate aminotransferase.
Baseline PFT results
RV
% predicted
120
100
80
60
40
20
0
DLCO
Bibasal crackles present Bibasal crackles absent
Fig.3. Association of lung volumes with presence or absence of bibasal crackles. (RV =
residual volume; DLCO = lung diffusion capacity for carbon monoxide; PFT = pulmonary
function test.)
Baseline PFT results
FEV1
% predicted
90
80
70
60
50
40
30
20
10
0FVC DLCO
Dry cough present Dry cough absent
Fig.2. Association of lung volumes with presence or absence of dry cough. (FEV1 = forced expiratory
volume in the 1st second; FVC = forced vital capacity; DLCO = lung diusion capacity for carbon
monoxide; PFT = pulmonary function test.)
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ILD is the most prevalent of these complications in our setting.
Clinical symptoms such as a dry cough and dyspnoea were accurate
predictors of severity and progression of disease when compared with
PFT results. e presence of Velcro crackles was a predictor of UIP.
Pulmonary infections, specically PTB, were common in this study.
Pulmonary symptoms may present before the onset of myositis, and
there should therefore be a high index of suspicion for SARDs in these
patients.
Declaration. MW is a member of the editorial board. e research for this
study was done in partial fullment of the requirements for TH’s MMed
(Int Med) degree at the University of the Witwatersrand.
Acknowledgements. e authors acknowledge the contributions of
DrRajiv Narsing, who contributed to the conception of the initial study
design.
Author contributions. TH, NG, MW: study conception and design. TH:
data collection. TH, MT, NG, MW: analysis and interpretation of results.
All authors reviewed the results and approved the nal version of this
manuscript.
Funding.None.
Conicts of interest.None.
1. Bohan A, Peter JB. Polymyositis and dermatomyositis. N Engl J Med 1975;292(7):344-
347. https://doi.org/10.1056/NEJM197502132920706
2. Hallowell RW, Ascherman DP, Dano SK. Pulmonary manifestations of polymyositis/
dermatomyositis. Semin Respir Crit Care Med 2014;35(2):239-248. https://doi.
org/10.1055/s-0034-1371528
3. Marie I, Hachulla E, Chérin P, etal. Interstitial lung disease in polymyositis and
dermatomyositis. Arthritis Rheum 2002;47(6):614-622. https://doi.org/10.1002/
art.10794
4. Fathi M, Lundberg IE, Tornling G. Pulmonary complications of polymyositis and
dermatomyositis. Semin Respir Crit Care Med 2007;28(4):451-458. https://doi.
org/10.1055/s-2007-985666
5. Chinniah KJ, Mody GM. e spectrum of idiopathic inammatory myopathies in
South Africa. Clin Rheumatol 2021;40(4):1437-1446. https://doi.org/10.1007/s10067-
020-05048-w
6. Cobo-Ibáñez T, López-Longo F-J, Joven B, etal. Long-term pulmonary outcomes
and mortality in idiopathic inammatory myopathies associated with interstitial
lung disease. Clin Rheumatol 2019;38(3):803-815. https://doi.org/10.1007/s10067-
018-4353-2
7. Marie I, Hatron PY, Dominique S, Cherin P, Mouthon L, Menard JF. Short-term and
long-term outcomes of interstitial lung disease in polymyositis and dermatomyositis:
A series of 107 patients. Arthritis Rheum 2011;63(11):3439-3447. https://doi.
org/10.1002/art.30513
8. Chen F, Li S, Wang T, Shi J, Wang G. Clinical heterogeneity of interstitial lung disease
in polymyositis and dermatomyositis patients with or without specic autoantibodies.
Am J Med Sci 2018;355(1):48-53. https://doi.org/10.1016/j.amjms.2017.07.013
9. Lega JC, Fabien N, Reynaud Q, et al. The clinical phenotype associated with
myositis-specific and associated autoantibodies: A meta-analysis revisiting the
so-called antisynthetase syndrome. Autoimmun Rev 2014;13(9):883-891. https://doi.
org/10.1016/j.autrev.2014.03.004
10. Mimori T, Imura Y, Nakashima R, Yoshifuji H. Autoantibodies in idiopathic
inammatory myopathy: An update on clinical and pathophysiological signicance. Curr
Opin Rheumatol 2007;19(6):523-529. https://doi.org/10.1097/BOR.0b013e3282f01a8c
11. Euwer RL, Sontheimer RD. Amyopathic dermatomyositis (dermatomyositis siné
myositis): Presentation of six new cases and review of the literature. J Am Acad
Dermatol 1991;24(6 Pt 1):959-966.
12. Hankinson JL, Odencrantz JR, Fedan KB. Spirometric reference values from a sample
of the general US population. Am J Respir Crit Care Med 1999;159(1):179-187.
https://doi.org/10.1164/ajrccm.159.1.9712108
13. Barst RJ, McGoon M, Torbicki A, etal. Diagnosis and dierential assessment of
pulmonary arterial hypertension. J Am Coll Cardiol 2004;43(12 Suppl S):40S-47S.
https://doi.org/10.1016/j.jacc.2004.02.032
14. Gotway MB, Freemer MM, King TE Jr. Challenges in pulmonary brosis. 1: Use
of high-resolution CT scanning of the lung for the evaluation of patients with
idiopathic interstitial pneumonias. orax 2007;62(6):546. https://doi.org/10.1136/
thx.2004.040022
15. Cottin V, ivolet-Béjui F, Reynaud-Gaubert M, etal. Interstitial lung disease in
amyopathic dermatomyositis, dermatomyositis and polymyositis. Eur Respir J
2003;22(2):245-250. https://doi.org/10.1183/09031936.03.00026703
16. Douglas WW, Tazelaar HD, Hartman TE, etal. Polymyositis-dermatomyositis-
associated interstitial lung disease. Am J Respir Crit Care Med 2001;164(7):1182-1185.
https://doi.org/10.1164/ajrccm.164.7.2103110
17. Fathi M, Dastmalchi M, Rasmussen E, Lundberg IE, Tornling G. Interstitial
lung disease, a common manifestation of newly diagnosed polymyositis and
dermatomyositis. Ann Rheum Dis 2004;63(3):297-301. https://doi.org/10.1136/
ard.2003.006122
18. Long K, Dano SK. Interstitial lung disease in polymyositis and dermatomyositis. Clin
Chest Med 2019;40(3):561-572. https://doi.org/10.1016/j.ccm.2019.05.004
19. Debray MP, Borie R, Revel MP, etal. Interstitial lung disease in anti-synthetase
syndrome: Initial and follow-up CT ndings. Eur J Radiol 2015;84(3):516-523. https://
doi.org/10.1016/j.ejrad.2014.11.026
20. Ebner L, Christodoulidis S, Stathopoulou T, etal. Meta-analysis of the radiological
and clinical features of usual interstitial pneumonia (UIP) and nonspecic interstitial
pneumonia (NSIP). PLoS ONE 2020;15(1):e0226084. https://doi.org/10.1371/journal.
pone.0226084
21. Bouros D, Wells AU, Nicholson AG, etal. Histopathologic subsets of brosing alveolitis
in patients with systemic sclerosis and their relationship to outcome. Am J Respir Crit
Care Med 2002;165(12):1581-1586. https://doi:.org/10.1164/rccm.2106012
22. Castelino FV, Varga J. Interstitial lung disease in connective tissue diseases: Evolving
concepts of pathogenesis and management. Arthritis Res er 2010;12(4):213. https://
doi.org/10.1186/ar3097
23. Cottin V, Cordier JF. Velcro crackles: e key for early diagnosis of idiopathic pulmonary
brosis? Eur Respir J 2012;40(3):519-521. https://doi.org/10.1183/09031936.00001612
24. Cruellas MG, Viana Vdos S, Levy-Neto M, Souza FH, Shinjo SK. Myositis-specic
and myositis-associated autoantibody proles and their clinical associations in a
large series of patients with polymyositis and dermatomyositis. Clinics (Sao Paulo)
2013;68(7):909-914. https://doi.org/10.6061/clinics/2013(07)04
25. Gupta L, Aggarwal R, Naveen R, etal. High prevalence of active tuberculosis in adults
and children with idiopathic inammatory myositis as compared with systemic lupus
erythematosus in a tuberculosis endemic country: Retrospective data review from a
tertiary care centre in India. Mediterr J Rheumatol 2021;32(2):134-142. https://doi.
org/10.31138/mjr.32.2.134
26. 2Yang Z, Lin F, Qin B, Liang Y, Zhong R. Polymyositis/dermatomyositis and
malignancy risk: A metaanalysis study. J Rheumatol 2015;42(2):282-291. https://doi.
org/10.3899/jrheum.140566
Received 30 October 2023. Accepted 14 June 2024. Published 11 October 2024.
