Early detection of pulmonary involvement in scleroderma patients By Mohamed Mostafa Metwally, MD, FCCP Assistant professor of chest diseases Assiut University

Pulmonary involvement is one of the most important causes of morbidity and mortality in scleroderma. Alveolitis develops in up to 80% of SSc patients and the progression to end-stage fibrosis occurs in 15%. Early detection of alveolitis in SSc is amenable to intravenous or oral Cyclophosphamide while delays in the treatment could be associated with disabling symptoms that may be incompletely reversible

Once it becomes clinically symptomatic, the prognosis of the affected patient becomes poor. So, prompt diagnosis of early fibrosing alveolitis is important for early initiation of therapy. The presentation of skin lesions in SSc is either diffuse or limited. The “diffuse’’ if skin thickening extends proximal to the elbows and knees or includes the trunk while the ‘‘limited ’’ if skin thickening is confined to the elbows and knees, or the face.

Aim of the work The aim of this study is to test the possible role of HRCT, pulmonary function test and TGF-ß in early detection of pulmonary affection in SSc patients at the subclinical level before being symptomatic and to test if there is any method to early predict this pulmonary affection.

Patients and methods Patients with SSc were recruited from rheumatology and rehabilitation and dermatology departments, Assiut University Hospitals Inclusion criteria: Age ≥ 18 years Diagnosis according to American College of Rheumatology criteria No evidence of clinical or radiological manifestations of ILD. Non-smokers for at least 6 months.

Exclusion criteria Patients with pulmonary infections and other possible causes of pulmonary fibrosis or on Cyclophosphamide therapy. Every patient gave and informed consent and the study was approved by the Assiut faculty of medicine ethical committee.

Each patient underwent history and clinical examination to check the presence of organ involvement with special emphasis on the extent and degree of skin thickness. Clinical assessment of fibrotic skin changes by the dermatologist to: Diagnose limited SSc from localized SSc where “diffuse’’ if skin thickening extends proximal to the elbows and knees or includes the trunk while the ‘‘limited ’’ subset if skin thickening is confined to the elbows and knees, or the face.

Assess the extent and severity of skin thickness using the modified Rodnan skin score (mRSs) by clinical palpation of 17 body areas on a scale of 0-3.

Investigations The possibility of pulmonary involvement was determined by: 1- Spirometry according to the ATS guidelines Diffusing capacity for CO (DLCO) according to the ATS guidelines High Resolution chest CT scan. 4- Serum TGF-ß in patients and 10 controls was also detected using ELISA.

Results

We recruited 30 female patients of scleroderma with a mean age (± SD) of ± years. High resolution chest CT showed abnormalities in only 8/30 cases (26%) in the form of mild basal ground glass opacities. Their FVC% predicted ranged from 58%- 100% with a mean (±SD) 82.83% ± 11.28%. Also, their diffusing capacity (DLCO) ranged from 65% to 128% of predicted with a mean (± SD) of 89.1 ± 14.8%.

High resolution chest CT abnormalities were significantly higher (P<0.05), while DLCO was significantly lower (P<0.05) in diffuse disease subset. Also, there was a statistically higher mean of serum TGF-ß in diffuse SSc in comparison to limited SSc and the same was in the whole SSc group in comparison to the controls. However, there was insignificant statistical relationship between Extent of disease and FVC% predicted (P>0.05).

By univariate analysis, the extent of scleroderma (either diffuse or limited) proved to be an independent risk factor for early detection of pulmonary involvement by both High resolution chest CT abnormalities (P = 0.049; OR: 6.42; 95% CI: ) and diffusion defect (P = 0.027; OR: 10.00; 95% CI: ) but not TGF-β (P = 0.091; OR: 0.45; 95% CI: ) in this cohort of pulmonary- asymptomatic patients.

CONCLUSIONS The diffuse presentation of scleroderma can be used as an independent risk factor for early detection of pulmonary involvement in patients presenting with no respiratory symptoms by early predicting high resolution chest CT abnormalities and diffusion defect (DLCO) but neither by FVC% predicted nor TGF-ß in this cohort of systemic sclerosis patients.