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

BACKGROUND: 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.

METHODS: 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.

FINDINGS: 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.

INTERPRETATION: 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.