Association between HCV induced mixed cryoglobulinemia and pulmonary affection: the role of TNF-alpha in the pathogenesis of pulmonary changes

ABSTRACT

Chronic hepatitis C virus [HCV] infection is associated with both pulmonary involvement and cryoglobulinemia. Therefore, this study was designed to investigate the relationship between pulmonary involvement and mixed cryoglobulinemia in chronic HCV infected patients and to investigate the role of TNF-alpha in the pathogenesis of pulmonary changes. After hospital ethics committee approval and formal patient consent were obtained, 100 patients with compensated hepatitis C virus infection as confirmed by PCR were recruited in this cross sectional study. Their demographic and laboratory data, abdominal ultrasound findings, pulmonary function tests [spirometry], arterial blood gas [ABG] parameters, TNF-alpha levels, and data from high-resolution chest CT were collected and analyzed using SPSS version 16, and a serum cryoglobulin assay was performed in all of the studied patients The prevalence of mixed cryoglobulinemia was 61.7% in the studied HCV patients. Pulmonary symptoms were observed in more than half of these patients. The most common complaint among the symptomatic patients was dyspnea [51.7%], followed by cough [43.3%]. Oxygen saturation [Spo[2] and Sao[2]%], and FEVi and FVC levels, were significantly decreased in the cryoglob-ulin positive patients compared to the cryoglobulin negative patients. A statistically significant correlation was found between the presence of cryoglobulins and FEV level, FVC level, serum albumin level, viremia level, thrombocytopenia and arterial blood gas parameters. No correlation was found between cryoglobulinemia and TNF-alpha level. The results of this study suggest that pulmonary involvement is common in patients with chronic HCV infection and mixed cryoglobulinemia. Cryoglobulinemia may lead to pulmonary involvement through vascular and interstitial deposition of cryoglobulins, which results in impaired gas exchange and airway affection