Cryptogenic Hepatitis and Bartonellosis

Abstract

To the Editor, We read with great interest the recent review on cryptogenic hepatitis (CH), Cryptogenic Chronic Hepatitis and Its Changing Guise in Adults, written by Dr. Czaja. Its frequency in the general population can be as high as 5.4% [1]. Dr. Czaja asks for ‘‘insights into CH that require a span of observation or reliance on deductions from a constellation of nonspecific features.’’ From our point of view, CH contains crypta (Latin meaning hidden or secret) etiologies. Alternatively, it could be called idiopathic hepatitis as it is not an independent disease entity. These etiologic factors may be infectious in origin and it is our inability to detect them that hinders our understanding of cryptogenic/idiopathic hepatitis. The best example is the hepatitis C virus. Before the 1990s, this hepatitis was considered cryptogenic and at that time CH had a different expression and outcome compared to current medical practice. As our knowledge and diagnostic capabilities advance, so will the clinical outcome [1]. In his manuscript, the author proposes a diagnostic algorithm based on an extensive literature review and his broad clinical experience working with liver disease patients. Even so, he recognizes that we must continue to look for other possible etiologies. We propose that bacterial hepatitis should be included in the first stage of assessment. Bartonella henselae can cause chronic hepatitis inflammation in adults or in children [2, 3]. These bacteria can be found worldwide. Cats are one of the most important reservoirs though many other mammals and arthropods have been identified as well. Humans can be asymptomatic or oligosymptomatic Bartonella spp. carriers [4–6]. Blood donors can also have Bartonella spp. bacteremia [7, 8]. Bartonella henselae can cause nonspecific liver inflammation as they can cause bacillary angiomatosis in liver, bacillary peliosis hepatis as well as granulomatous hepatitis with or without necrosis [2, 3]. Bartonella spp. infection has been reported in liver transplant recipients [9– 11]. The recipients may have been previously infected or contracted the infection through donor liver [5] or blood transfusion [12]. Bartonella spp. can also co-infect patients with viral hepatitis B and C [13–15] and, perhaps, could be related to recurrences after liver transplantation or de novo hepatitis in these patients. Undiagnosed Bartonella spp. infection may influence the survival rate of this population of transplant recipients, especially those with CH. Coordinated international efforts should be initiated to discover other etiologies to CH. We hypothesize that infection with the bacteria Bartonella spp. is an etiologic agent of CH/idiopathic hepatitis and propose that testing for this pathogen needs to be incorporated into the routine algorithm for liver transplant donors and recipients. P. E. N. F. Velho (&) M. E. Ericson Department of Dermatology/Center for Drug Design, University of Minnesota, 420 Delaware St. S.E., MMC98, Minneapolis, MN 55455, USA e-mail: pvelho@unicamp.br; pevelho@umn.edu