The adult kidney 24 years after childhood Henoch-Schönlein purpura: a retrospective cohort study

Henoch-Schönlein purpura arising in childhood could cause renal impairment or even an end-stage renal disease later in life. We aimed to assess long-term outcome of childhood Henoch-Schönlein purpura after 24 years. We studied a cohort of 26 boys and 26 girls who were treated for Henoch-Schönlein purpura at Helsinki University Hospital during 1964–83. Mean follow-up was 24·1 years (SD 6·0; 16·4–36·5). All participants were asked about their state of health in a questionnaire, and 47 (90%) were examined by a doctor. Patients' medical history data were obtained from health-care centres and regional hospitals. Seven (35%) of 20 adults who had severe Henoch-Schönlein purpura and glomerulonephritis at onset had renal impairment as adults, compared with two (7%) of 27 with mild or no renal symptoms at onset (relative risk 4·7, 95% CI 1·3–18·7). Relative risk for a poor outcome was 5·0 in women (1·1–32·5) and 2·0 in men (0·2–17·5). All patients with no renal symptoms at onset had a good outcome after 24 years of follow-up. Severity of first kidney biopsy finding did not correlate with risk of a poor outcome. 16 (70%) of 23 pregnancies had been complicated by hypertension, proteinuria, or both. Five (56%) of the nine women with complicated pregnancies had a poor renal outcome. Long-term follow-up of all patients who had Henoch-Schönlein purpura with severe renal symptoms at onset is needed during adulthood. All women who had even mild renal symptoms at onset of Henoch-Schönlein purpura should be carefully observed during and after pregnancy.