Lack of Evidence for Bacterial Infections in Skin in Patients With Systemic Sclerosis

Abstract

BackgroundIn some patients with systemic sclerosis (SSc), persistent bacterial infection involving dermal microvascular endothelial cells may result in endothelial injury, leading to the obliterative microvasculopathy typical of the disease. Alternatively, in some patients with SSc persistent bacterial infection involving activated dermal fibroblasts or other cells found in scleroderma skin might result in the fibrosing features of this disease. In this study, we investigated bacterial infection in skin in patients with SSc. MethodsChlamydiae of many species are known to undergo persistent infection. Highly sensitive and specific PCR assays targeting chromosomal DNA sequences from C. trachomatis and C. pneumoniae were used to screen skin biopsy samples from each of 18 patients and 26 control individuals. Additional screening was performed using a highly sensitive “pan-bacteria” PCR screening system. ResultsAll patient and control samples proved to be PCR-negative for both chlamydial species. Similarly, all patient and control samples were PCR-negative when the broad range pan-bacteria assay system was used. ConclusionAlthough some caveats apply, the data presented here do not support the contention that persistent bacterial infections play an important role in the pathogenesis of SSc.