The early onset of type 1 autoimmune hepatitis has a strong genetic influence: role of HLA and KIR genes.

We have previously reported a strong association between HLA-DRB1*1301 and type 1 pediatric autoimmune hepatitis (PAH) and between HLA-DR*0405 and adult autoimmune hepatitis (AAH). Because human killer cell immunoglobulin-like receptors are known to be associated with susceptibility to autoimmune diseases, we investigated the frequencies of HLA-A, B, C, DRB1 and KIR genes in 144 type 1 PAH and 86 AAH patients, which were compared with 273 healthy controls. We demonstrated in PAH the increased frequency of the functional form of KIR2DS4-Full Length (KIR2DS4-FL), which in combination with HLA-DRB1*1301 revealed a strong synergistic effect (odds ratio=36.5). PAH-KIR2DS4-FL+ subjects have shown an increased frequency of their putative HLA-C*02, 04 and 06 ligands. KIR analysis of PAH also revealed a decreased frequency of KIR2DL2 gene and its ligand. In contrast, AAH cases have shown a weaker increased frequency of KIR2DS4-FL, a lack of synergistic effect with HLA class II antigens and a moderate association with HLA-DRB1*0405. Of note, we demonstrated that liver T cells have a unique pattern of KIR expression. These results show a KIR gene involved in autoimmune hepatitis and suggest a stronger genetic influence for the early onset type I autoimmune hepatitis.

[Anti-actin antibodies in acute viral hepatitis A in children]. / Investigación de anticuerpos antiactina en hepatitis aguda por virus A en niños.

UNLABELLED: Hepatitis A Virus (HAV) infection has been proposed as a possible trigger of autoimmune hepatitis type I. We have previously reported the presence of anti-actin antibodies en protracted hepatitis A. At present the presence of anti-actin antibodies in acute uncomplicated hepatitis A is unknown. The aim of this study was to evaluate the incidence and persistence of anti-actin antibodies un children with acute hepatitis A. MATERIALS AND METHODS: 38 patients, 21 female and 17 male, with mean age of 6.5 years (range 2-13 years) were included. All patients were anti HAV IgM positive. The patients were clinically controlled and laboratory determinations such as ALT/AST, gammaglobulin, gamma GT, nuclear, smooth muscle (anti-actin specificity) and liver-kidney-microsome type I (anti-LKM) antibodies, were evaluated at admission and at the first, third and fifth month. Anti-actin antibodies were determined by indirect immunofluorescense (IIF) on rat kidney, stomach and liver sections and also on monolayers of cultured fibroblasts. Titers higher than 1/40 were considered positive. RESULTS: 18 patients (47.3%) were anti-actin positive in the first determination (titers 1/40 and 1/80). In 4 patients (12.9%) these antibodies remained positive up to one month. All patients were negative 5 months after the onset of illness. ANA and anti-LKM were negative in all cases. CONCLUSIONS: 1) This data demonstrate the presence of anti-actin antibodies in children with uncomplicated HAV hepatitis. 2) The antibodies remained positive for a short period of time. 3) Titers were lower than in autoimmune hepatitis type I. 4) Taken together these results suggest that anti-actin antibodies would be an expression of non specific stimulation of lymphocyte B.

[Renal cell carcinoma producing erythrocytosis due to inappropriate production of erythropoietin]. / Eritrocitosis secundaria a la producción inapropiada de eritropoyetina por un carcinoma de células renales.

Erythrocytosis, or polycythaemia, is an increase, in absolute terms, of the erythrocyte mass. The most common solid tumour related to this phenomenon is renal cell carcinoma, which can produce erythrocytosis by increasing erythropoietin production. About 30% of symptomatic renal cell carcinomas are diagnosed due to the appearance of a paraneoplastic syndrome. Polycythaemia is one of these. Surgery, (radical or partial nephrectomy), is the treatment of choice in renal cell carcinoma and helps to keep the erythrocytosis situation under control.