Renal function and blood pressure five years after Puumala virus-induced nephropathy

Background. Nephropathia epidemica (NE) is a mild form of hemorrhagic fever with renal syndrome caused by Puumala hantavirus. Its long-term prognosis is considered favorable. Some reports suggest, however, that a previous han tavirus infection increases the risk of hypertension. Methods. We studied 46 previously healthy subjects (26 males and 20 females , mean age of 44 years) who had serologically confirmed NE three to seven y ears previously, and 38 healthy, seronegative controls (22 males and 16 fem ales, mean age of 44 years). Ambulatory blood pressure (ABP) was monitored. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) we re determined by (51)CrEDTA and I-121-hippurate clearances, respectively. T he filtration fraction (FF) was calculated. Quantitative 24-hour urinary pr otein excretion (UprotE) and timed overnight urinary excretion of alpha(1)- microglobulin were measured. Results. The NE patients had a higher mean ambulatory systolic BP than the controls (123 +/- 13 vs. 117 +/- 9 mm Hg, P = 0.008). GFR and FF were incre ased in patients compared with controls (GFR, 120 +/- 20 vs. 109 +/- 14 mL/ min/1.73 m(2), P = 0.006; FF, 19 +/- 3 vs. 18 +/- 3%, P = 0.030), but ERPF did not differ between the groups. The patients also had higher UPE than th e controls (median 0.18 g/day, range 0.12 to 0.38 ks. median 0.14 g/day, ra nge 0.09 to 0.24, P < 0.001, respectively). The overnight urinary excretion rate of alpha(1)-microglobulin exceeded 7 mu g/min in nine patients. Conclusion. Three to seven years after NE, the patients had higher GFR and FF, more proteinuria, and higher ambulatory systolic BP compared with the h ealthy controls. NE may thus cause mild renal lesions and alterations in BP in some patients.