Introduction: The aim of this study was to estimate the frequency of medium-term renal involvement, in a series of adult patients with Henoch-Schönlein purpura treated in a dermatology department.
Patients and methods: Seventeen patients with Henoch-Schönlein purpura followed from 1991 to 1997 in the department of dermatology were included in the study. Renal tests included: research of microscopic hematuria, proteinuria, plasma creatinine levels and calculated creatinine clearance which were measured during initial hospitalization and at the date of the study in May 1998.
Results: 10 men and 7 women (mean-age 51 years) were followed up for 39 months (6 to 79 months). Initial renal involvement was observed in 11 patients (65 p. 100). A microscopic hematuria was also observed in 9 patients (53 p. 100), a proteinuria in 6 (35 p. 100), an association of hematuria and proteinuria in 4 (23.5 p. 100). No patient had renal failure. In May 1998, only 2 patients (11.7 p. 100) had renal involvement, that consisted of proteinuria: 3.3 and 3. 9 g/d respectively, with no renal failure.
Discussion: The 65 p. 100 frequency of renal involvement discovered during the acute phase of HSP in our series was similar to other series mentioned in the literature, which mainly consisted of hematuria and/or proteinuria. The frequency of long-term renal involvement depends on the origin of patient recruitment. Nephrological studies have reported high levels of renal involvement, that probably overestimated the true frequency. In the present study, as well as in two other studies from a non-nephrological recruitment, the frequency of long-term renal involvement was estimated between 11 p. 100 and 16 p. 100 and was primarily persistent proteinuria.
Conclusion: The frequency of renal involvement in the adult patient with HSP during the acute phase of the disease and after a medium-term follow-up was approximately 50 p. 100 and between 11 p. 100 to 16 p. 100 respectively.