Tubular Proteinuria and Glomerular Filtration 6 Years after Puumala Hantavirus-Induced Acute Interstitial Nephritis

Abstract

Background/Aims: We previously found increased urinary protein excretion, glomerular filtration rate (GFR) and blood pressure in a retrospective analysis of patients with previous nephropathia epidemica (NE). Here, we evaluated the long-term outcome after NE in a prospectively recruited patient group. Methods: Proteinuria, GFR and ambulatory 24-hour blood pressure were assessed 4–7 years (mean 6) after acute NE in 37 patients, and these values were compared to those from 38 seronegative controls. Results: Six years after NE, the prevalence of elevated urinary α₁-microglobulin excretion was higher in the patients than controls (9/35 vs. 1/38; p = 0.005). The patients also had higher urinary protein excretion (0.17 ± 0.05 vs. 0.14 ± 0.04 g/day; p = 0.006), GFR (119 ± 19 vs. 109 ± 14 ml/min/1.73 m²; p = 0.016) and mean systolic (123 ± 11 vs. 117 ± 9 mm Hg; p = 0.012), nighttime systolic (109 ± 11 vs. 100 ± 9 mm Hg; p = 0.001) and nighttime diastolic blood pressure (70 ± 7 vs. 66 ± 7 mm Hg; p = 0.035) than the controls. Conclusions: These results confirm our previous findings of a higher prevalence of tubular proteinuria and increased urinary protein excretion, GFR and systolic blood pressure 6 years after acute NE.

Community Acquired Severe Acute Kidney Injury Caused by Hantavirus-Induced Hemorrhagic Fever with Renal Syndrome Has a Favorable Outcome

“…Patients studied 3-7 years after the acute infection were found to have higher GFR determined by 51 CrEDTA clearance, more proteinuria, and higher ambulatory systolic blood pressure compared to healthy controls [38,40]. However, 10 years after the acute infection, the glomerular hyperfiltration and proteinuria had disappeared and the prevalence of hypertension was no longer significantly higher than in controls [34].…”

“…The study cohort consisted of 556 PUUV-infected patients, who had participated in our previous clinical studies [12,17,18,19,24,25,26,27,28,29,30,31,32,33,34,37,38,39,40,41]. The diagnosis of acute PUUV infection was serologically confirmed in all cases.…”

The Severity of Acute Puumala Hantavirus Infection Does Not Predict the Long-Term Outcome of Patients

“…We have previously found that patients have higher GFR and blood pressure and greater urinary protein excretion 5–6 years after acute interstitial nephritis (AIN) caused by the Puumala hantavirus compared with seronegative healthy controls [7,8]. The literature offers only limited data on prognostic factors in the long-term outcome of AIN.…”

“…In 2004, 4–7 (median 6) years after acute NE, 43 out of these 70 patients attended a scheduled follow-up examination. The clinical characteristics of these patients have recently been described in detail [8]. Six of the 43 patients were now excluded; 4 patients had had hypertension before acute NE, 1 had diabetic nephropathy and 1 mesangial glomerulonephritis.…”

“…However, we have previously found in 2 independent groups of patients that 5–6 years after acute NE patients had higher systolic blood pressure and a glomerular filtration rate (GFR), and greater urinary protein excretion compared with healthy seronegative controls [7,8]. As far as we know, no studies have addressed the effect of clinical severity of the acute disease on the possible long-term consequences several years after NE.…”