Predictive factors for renal sequelae in adults with Henoch-Schönlein purpura

To examine the outcome and risk factors for renal sequelae in an unselected population of adults with Henoch-Schonlein Purpura (HSP).

Retrospective study of adult patients (> 20 years) with biopsy proved cutaneous vasculitis diagnosed as having HSP seen at a single center between 1984 and 1998. Patients were classified as having HSP according to proposed criteria. Only those patients with a followup of at least 1 year were included in this study of renal sequelae.

Twenty-eight patients with a mean followup of 5.5 years fulfilled the inclusion criteria. When the study was concluded, 10 patients (36%) had renal sequelae and 2 (7%) had renal insufficiency. Men outnumbered women. However, neither a previous history of drugs, gender, nor age at disease onset was associated with a higher risk of permanent renal involvement. Patients with hematuria at disease onset or renal involvement during the course of the disease more commonly developed renal sequelae (p < 0.001). The presence of anemia (p = 0.05) at the time of diagnosis and the onset in summer (p < 0.05) were also more common in those with permanent renal involvement (renal sequelae). Patients with relapses had also a higher trend to develop renal sequelae (p = 0.07). All patients who fulfilled more than 2 of these 5 risk factors developed permanent renal involvement. With this model we were able to predict renal sequelae in 8 of the 10 patients who had this complication. The Goodman-Kruskal gamma test value was 0.92 (95% CI 0.78-1.00).

In unselected adults with HSP, permanent renal involvement (renal sequelae) is not uncommon. Hematuria at disease onset and persistence of renal manifestations during the course of the disease are significant indicators of possible development of renal sequelae. These manifestations plus other features such as onset in summer, anemia at disease onset, or relapses of the disease may predict the development of renal sequelae in most patients.