HLA alleles are known to be associated with susceptibility to develop autoimmune hepatitis (AH), and hepatitis A virus (HAV) infection is postulated as a putative trigger for AH. We investigated whether HLA may influence the outcome of the HAV infection by studying 67 children with self-limited and 39 children with protracted forms of this infection. HLA typing of the uncomplicated forms showed no significant increase of any HLA class I or II alleles. In contrast, DRB1*1301 was present in 46.1% of the children with protracted forms (vs. 9.8% in healthy controls; relative risk [RR]: 7.6; 2 ‫؍‬ 33.3; P ‫؍‬ 2 ؋ 10 ؊9 ). In uncomplicated hepatitis, 45% developed anti-smooth muscle antibody (SMA)/actin antibodies, but only 1 child had detectable antibodies after 3 months of infection onset. In contrast, after 1 year, 69% of the patients suffering protracted forms had titers of anti-SMA/actin antibodies that ranged between 1:40 and 1:160. Within their follow-up, 2 patients developed a Hashimoto's thyroiditis, but the remaining patients showed no signs of developing autoimmune hepatitis. We conclude that the DRB1*1301 haplotype is strongly associated with the protracted forms of HAV infection and suggest that the infection allows a sustained release of liver self-antigens. However, other still-unknown susceptibility genes are required for the full development of pediatric AH. (HEPATOLOGY 2001;33:1512-1517

Although molecular diagnosis has been available in our center for the past 10 years, there is no doubt that awareness for early recognition of immunodeficiency should be improved through broader and more comprehensive education programs emphasizing characteristics of patients with immunodeficiencies.

Summary. We investigated the prognostic significance of soluble interleukin 2 receptor (sIL‐2r) levels in the pre‐ and post‐treatment serum of paediatric patients with Langerhans cell histiocytosis (LCH). Serum levels of sIL‐2r from 32 LCH patients and 14 healthy controls were determined using enzyme‐linked immunosorbent assay. The LCH patients were classified, evaluated and treated according to the Histiocyte Society's protocols. The following clinical stages were considered: single‐system disease (A) divided into single‐site (A1; n=4), multiple‐site (A2; n=9), and multisystem disease (B) without organ dysfunction (B1; n=5) and with organ dysfunction (B2; n=14). Pretreatment concentrations of sIL‐2r were markedly increased at diagnosis in LCH patients compared with controls [in pg/ml, median (range) 9200 (1124–40000) versus 610 (343–800)], P < 0·0001. Levels differed significantly between stages A [3250 (1124–11000)] and B [22750 (3400–40000)], P < 0·05, and between substages A2 and B2, P < 0·05. There was a significant correlation between clinical stages and sIL‐2r serum levels, r=0·7996 (P < 0·0001). Patients with ≥ 17500 pg/ml of sIL‐2r had a 30‐month survival of 0·417 (SEM: 0·142) compared with those with levels < 17500 pg/ml, who presented a 30‐month survival of 0·848 (SEM: 0·100) (log‐rank, P < 0·0001). In multivariate analysis, sIL‐2r levels ≥ 17500 pg/ml were found to have greater predictive strength than other well‐known prognostic factors.

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Patients with LCH have elevated levels of IL-1Ra and TNF, which decrease after chemotherapy.