Analysis of human foamy virus (HFV) as a putative pathogen for autoimmune diseases

我们在此报告日本家族性地中海热（FMF）患者中人类泡沫病毒（HFV）感染的证据。虽然HFV是第一个被报道的人类逆转录病毒，但并没有与特定疾病的明确关系的报道。然后，我们假设HFV可能是一些自身免疫性疾病的推定病原体之一，并对320例IPF、结节病、SLE、RA、癌症和3例FMF患者进行了HFV基因元件的检测。采用PCR扩增方法，与猪流感病毒cDNA克隆进行Southern blot杂交，鉴定猪流感病毒基因在基因组DNA中的存在。在所有FMF患者中观察到HFV基因元件的存在。其他患者均未出现甲型h1n1流感病毒阳性信号。FMF是一种病因不明的疾病，以周期性发热、胸痛、腹痛和关节痛等症状为特征。虽然FMF被认为是一种遗传性疾病，但许多FMF患者并没有明确的遗传背景。我们的结果显示，日本的一个FMF亚群已经感染了HFV。由于日本的FMF患者很少，所以很难得出明确的结论。但我们认为我们的结果可以部分支持HFV参与FMF发展的观点，而FMF不能仅用遗传方式来解释。

We report here the evidence of Human Foamy Virus (HFV) infection in patients with familial Mediterranean fever (FMF) in Japan. Although HFV is the first reported human retrovirus, no definite relation to a specific disease has been reported. Then, we hypothesized that HFV might be one of putative pathogens for some of autoimmune diseases and surveyed to detect HFV gene elements in 320 patients with several diseases including IPF,sarcoidosis, SLE,RA,cancer and 3 cases of FMF.The presence of HFV gene elements in genomic DNA was evaluated by the PCR amplification followed by Southern blot hybridization with HFV cDNA clone. Doing so, existence of HFV gene element was observed in all patients of FMF.None of other patients showed positive signals of HFV provirus. FMF is a disease of unknown etiology characterized with symptoms such as periodic fever, chest pain, abdominal pain and arthralgia. Although FMF is considered to be an inherited disease, there are many FMF patients without having clear genetic background. Our result revealed that a subgroup of FMF in Japan has already been infected with HFV.Because we have very few patients of FMF in Japan, it is difficult to get clear conclusion. But we think that our result could partially support the idea that HFV takes part in the development of FMF which cannot be explained by an inherited fashion alone.