Interstitial lung disease in South Africans with systemic sclerosis
Date
2015-04-17
Authors
Ashmore, Philippa
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
BACKGROUND: Interstitial lung disease (ILD) is one of the leading causes of death
in systemic sclerosis (SSc).
PATIENTS AND METHODS: A retrospective review of case records, over 20 years,
of SSc patients attending a tertiary Connective Tissue Diseases Clinic. Comparisons
between ILD and non-ILD groups at presentation were performed in order to identify
baseline associations and predictors of ILD.
RESULTS: Of the 151 participants that met inclusion criteria, 60 (40%) had ILD. On
multivariate analysis the only three variables to remain significant were median
duration of disease (OR 1.2 (1.1-1.3); p<0.001), speckled anti-nuclear antibody
(ANA) pattern (OR 2.95 (1.22-7.15); p=0.017) and bibasal crackles (OR 5.4 (2.1-
13.5); p<0.0001).
Univariate analysis of baseline variables associated with interstitial lung
disease in systemic sclerosis.
Baseline Variable ILD (n=60) Non-ILD (n=91) OR (CI 95%) p
Bibasal crackles
(%)
28 (46.7) 10 (11.0) 7.1 (3.1-16.3) <0.0001
Diffuse disease
subtype (%)
49 (81.7) 45 (48.9)
4.6 (2.1-9.9) <0.001
Limited disease
subtype (%)
8 (13.3)
38 (41.3)
0.2 (0.1-0.5) <0.001
Anti-centromere
antibodies (%)
0 (0.0) 10 (13.0) - 0.006
Cough (%) 21 (35.0) 15 (16.5) 2.7 (1.3-5.9) 0.007
Median duration in
years (IQR)
6.1 (8.3) 4.0 (5.0) 2.2 (1.8-2.4) 0.009
Speckled ANA
pattern (%)
29 (50.9) 25 (32.5) 2.5(1.2-4.9) 0.010
Dyspnoea (%) 27 (45.0) 24 (26.4) 2.3 (1.1-4.6) 0.014
Gold mining history
(%)
5 (8.3) 1 (1.1) 8.2 (0.9-71.9) 0.037
ANA=antinuclear antibody; ILD=interstitial lung disease; IQR= interquartile range; OR=odds ratio
Additionally, dyspnoea was associated with ILD severity (p=0.008). Bibasal crackles
(p=0.014), increased plasma urea (p=0.041), and reduced serum albumin (p=0.007)
were associated with mortality in the ILD group.
CONCLUSION: Interstitial lung disease in South African SSc patients is common.
The diffuse cutaneous disease subtype appears to drive the disease process. There
should be a high index of suspicion for ILD in SSc patients presenting with a gold
mining history, dyspnoea, cough and bibasal crackles.
Description
A research report submitted to the Faculty of Health Sciences, University of the
Witwatersrand, in partial fulfilment of the requirements for the degree of Master of
Medicine in the branch of Internal Medicine.
Johannesburg, 2014