Recurrent post-infective Henoch-Schönlein syndrome: a genetic influence related to HLA B35?
The clinical features, laboratory findings, infection stimuli and HLA phenotypes of five young adults with recurrent episodes of Henoch-Schönlein syndrome (HSS) are reported. We define recurrences as the reappearance of the characteristic purpuric rash and associated symptoms more than 8 weeks after the onset of the original episode of purpura. All patients had documented evidence of a bacterial or viral infection before one or more of the relapses, the periods between which varied from 1 to 13 years. Four of our five patients possessed the HLA B35 phenotype and two of these four patients were also HLA B18 antigen positive. Those with the HLA B35 haplotype had recurrent episodes of purpura with nephritis triggered by minor pharyngeal (viral or bacterial) infections. The HLA B35 haplotype has a frequency of 4% in the indigenous Scottish population and has previously been linked with single episodes of the Henoch-Schönlein syndrome with nephritis in German, Slavic and French patients. It has not previously been related to recurrent episodes of the syndrome. We postulate that patients who are HLA B35 positive may be genetically more susceptible to recurrent episodes of HSS with nephritis, stimulated by a heterogeneous group of infective stimuli and resulting in a protracted illness with significant renal involvement.