Current concepts and dilemmas in idiopathic interstitial pneumonias

Viral hepatitis and interstitial lung diseases: can HRCT assess their relation and characterize its pattern?

Background

Clinical and pathological studies suggested the presence of a relation between active viral hepatitis and interstitial lung diseases (ILD) ranging from mild to moderate relation. Most studies attribute this relation to viral geno-physiological characteristics. The purpose of the study is first to assess the role of high-resolution computed tomography (HRCT) in evaluating the relation between viral hepatitis and ILDs, then to characterize the predominant pattern of ILD that affects patient management and prognosis.

Results

This prospective study was conducted on 300 patients with viral hepatitis. They were divided into three groups of patients according to blood viremia assessed by polymerase chain reaction (PCR) as well as the diffusing capacity of carbon monoxide (DlCO) in examined pulmonary function tests (PFT). Group [A] included 100 patients with low or moderate viremia and showing normal or low to moderate DlCO decline (> 50%). Group [B] included 100 patients with high viremia and showing normal or low to moderate DlCO decline (> 50%). Group [C] included 100 patients with high viremia and showing a restrictive DlCO decline pattern (< 50%). The study included 182 males and 118 females with a ratio of 3:2, while the age ranged between 40 and 70 years (mean age of 55 years). No ILD was found among the group [A] patient. Meanwhile, 27% of patients in the group [B] showed a non-fibrotic pattern of ILD and 50% of patients in the group [C] showed a fibrotic pattern of ILD. Among patients in group [B] and group [C] together, 77 patients showed ILD accounting for 38.5%.

Conclusion

In concordance with the results of the previous clinicopathological and geno-physiological studies, our HRCT results further established a mild to moderate relation between active hepatitis and ILD regardless of the pulmonary functions. The fibrotic pattern of ILD with poor response to therapy and poor prognosis was found in those patients with concomitant restrictive PFT and rapidly progressive symptoms.