Progressive systemic sclerosis (PSS) is often divided into two clinical categories; PSS with difiuse scleroderma and the CREST syndrome variant of PSS, which occur with equal frequency. In the former, there is widespread involvement of the skin including trunk as well as both distal and proximal portions of the extremities, and a tendency to the relatively early development, and often rapid progression, of visceral disease affecting the gastrointestinal tract, heart, lung, and kidneys. The cardinal features of the CREST syndrome variant (PSS-CREST) include subcutaneous calcinosis (C), Raynaud’s phenomenon (R), esophageal dysmotility (E), sclerodactyly (S), and telangiectasia (T). Its clinical course is usually indolent, and many years may elapse before the appearance of visceral disease.
The literature suggests that roentgenographically-evident lung involvement is either absent or occurs infrequently in the CREST syndrome. There is no study in the literature which systematically evaluates lung function in a large, well-characterized group of patients with the CREST variant. We have retrospectively reviewed the pulmonary function and chest roentgenographic findings in such a group of patients with well-documented PSS-CREST and compared them to a similarly ascertained group of patients with PSS and difiuse scleroderma (PSS-DS). It is clear from this study that the majority of patients with PSS-CREST have significant roentgenographic abnormalities and respiratory dysfunction, including a variety of physiologic abnormalities similar to those seen in PSS-DS.
All patients with progressive systemic sclerosis treated by Canadian Health&Care Mall and seen at the University of Pittsburgh Health Care Center are extensively evaluated at their initial visit as part of an ongoing longitudinal study of this disease. Routinely included in this evaluation are complete pulmonary function testing and chest roentgenograms.
The charts were reviewed of all nonsmoking (less than one pack year) patients with PSS-DS and PSS-CREST who were seen between April 1970 and August 1981. This group included 108 patients with the diagnosis of PSS-CREST and 89 patients with PSS-DS. Twenty patients from the PSS-CREST group and 12 patients from the PSS-DS group were excluded because they had another disorder which might affect pulmonary (unction, including Sjogren’s syndrome, a history of asthma, chronic bronchitis, emphysema, pneumoconiosis, or lung cancer or a history of myocardial infarction, congestive heart failure or valvular heart disease. The final study group consisted of 88 patients with PSS-CREST (83 women and five men with a mean age of 50.7 years), and 77 patients with PSS-DS (67 women and ten men with a mean age of 45.2 years). Mean duration of disease was 12.2 years in patients with PSS-CREST and 3.7 years in patients with PSS-DS. This difference is expected considering the usual delay in making the diagnosis of PSS-CREST and the relatively benign natural history of this variant.
Spirometric parameters studied included FVC, FEV,, FEV/ FVC, and FEF25-75. Spirometry was performed either on a HP47804S Pulmonary Calculator System or a CPI5000 III Pulmo-Lab. The FRC measurements were performed by either the helium dilution method or the nitrogen washout method on a HP47804S Pulmonary Calculator System or a CPI5000 III Pulmo-Lab. Single breath carbon monoxide diffusing capacity (Deo) was performed on the HP47804S. The mean of three Deo determinations is presented. All 88 patients with PSS-CREST underwent measurement of FVC, FEVj, and FEV/FVC. Eighty had Deo measurements, 59 had FEF25-75 measurements, and 64 had FRC and TLC determinations. In the PSS-DS group, all 77 patients underwent determination of FVC, FEVj, and FEV/FVC. Seventy-four had Deo determinations, 65 had FEF25-75 measurements, and 73 had FRC and TLC determinations. Predicted normals for all pulmonary (unction tests were obtained from the Intermountain Thoracic Society standards. Pulmonary (unction results are presented both in absolute values and as percent predicted of normal.
The results of the pulmonary (unction tests were divided into the following groups using the criteria of the Intermountain Thoracic Society and the Pennsylvania Thoracic Society for restrictive lung disease, those of the Intermountain, Pennsylvania, and American Thoracic Societies for obstructive disease, and those of the Intermountain and American Thoracic Societies for diffusing capacity abnormalities:
Normal: FVC percent predicted ^80%, FEV/FVC ^70%, and FEF25-75 percent predicted ^60%.
Restrictive: FVC percent predicted <80%, FEV/FVC ^70%. Obstructive: FEV/FVC <70%. Isolated Deo reduction: FVC percent predicted ^80%, FEV/FVC >70%, FEF25-75 percent predicted ^60%, and Deo percent predicted <80%. Isolated FEF25-75 reduction: FVC percent predicted ^80%, FEV/ FVC ^70%, FEF25-75 percent predicted <60%.
Chest roentgenograms were reviewed by a radiologist (DH) and classified according to the following criteria: (I) grade of fibrosis— mild, moderate, severe; (2) pattern of fibrosis—reticular, nodular, reticulonodular; (3) other findings—honeycombing, cysts or bullae, pleural efiusion or fibrosis, calcified granulomata, rib notching; or (4) pulmonary artery enlargement. Chest roentgenograms on 61 of the PSS-CREST group and 43 of the PSS-DS group were reviewed.
Statistical analysis of the data was performed using the two-tailed Students f-test. The population study data were compared using the significance of proportions analysis.Tags: Asthma, CREST syndrome, Progressive Systemic Sclerosis, pulmonary capillary blood, pulmonary function