Glomerulonephritis emerging shortly after Puumala hantavirus infection: a report on 7 patients.

Aims: Nephropathia epidemica (NE) is mild type of hemorrhagic fever caused by Puumala (PUU) hantavirus. Renal biopsy typically shows acute tubulointer-stitial nephritis and complete recovery is the usual outcome. We previously described 5 patients with membranoproliferative glomerulonephritis (MPGN) after acute NE. We now report on 7 more patients who developed biopsy-confirmed glomerulonephritis (GN) during the convalescent phase of NE. Material and methods: We present case histories of 7 patients with nephrotic-range proteinuria concomitant with hematuria after serologically verified NE. Results: Renal biopsy specimens disclosed MPGN in 5 patients, membranous GN (MGN) in 1 and mesangial GN (MesGN) in 1. All patients achieved remission of nephrotic syndrome within a median time of 0.6 years (range 0.5 - 5.5 y). The median follow-up time was 1.7 years (0.7 -15.6 y). Conclusions: As a rare phenomenon, nephrotic syndrome may emerge during the convalescent phase of acute PUU hantavirus infection. In most cases the prognosis of GN caused by NE seems to be favorable.