Clinical impact of altered immunoglobulin levels in Henoch–Schönlein purpura

Abstract

The aim of the present study was the identification of immunological features, present at the time of diagnosis, that would predict the severity of Henoch-Schönlein purpura and its outcome. A cohort study was carried out in a tertiary pediatric hospital of 69 children with Henoch-Schönlein purpura, in whom serum complement components C3, C4 and IgA, IgM, IgG were repeatedly determined. During the acute phase of the disease in 54/69 patients (78.3%) immunological imbalances were observed. In 24/54 cases (44.4%) certain complications involving the kidneys and the gastrointestinal tract were noted as opposed to in 3/15 children (20%) without immunologic abnormalities. In 50/69 children (72.5%), elevated serum IgA was detected and 16 of them (32%) developed renal involvement while only 1/19 children (5.3%) with normal IgA concentration had renal involvement. Considering separately the group of 9/69 children (13%) with increased IgM and those with normal IgM levels (53/69; 76.8%), irrespective of IgA and IgG concentration, we found a comparable percentage of children who had both renal and intestinal involvement without, however, developing severe complications, which were exclusively seen in patients with increased IgA (5/7 children) and reduced IgM levels. Serum C3 fraction was elevated in 26 children (37.7%) and in 73% of cases it was associated with increased serum IgA values. Renal involvement was seen in 32% of children with increased IgA values. Most importantly, elevated IgA concentration along with reduced IgM levels was associated with higher prevalence of severe complications.