Alcohol Consumption and Its Influence on the Clinical Picture of Puumala Hantavirus Infection.

Puumala hantavirus (PUUV) causes hemorrhagic fever with renal syndrome. Characteristic clinical findings include acute kidney injury (AKI), thrombocytopenia, and capillary leakage. Smoking increases the risk of severe AKI, but it is not known whether alcohol consumption predisposes patients to a more severe infection. Liver and pancreatic enzymes, as well as biomarkers of alcohol consumption (gamma-glutamyl transferase, GGT; carbohydrate-deficient transferrin, CDT; GGT-CDT combination; and ethyl glucuronide, EtG), were measured from 66 patients with acute PUUV infection during hospitalization and at the convalescence phase. Alcohol consumption was present in 41% of the study population, 15% showing signs of heavy drinking. Alcohol use did not affect the severity of PUUV induced AKI nor the overall clinical picture of the infection. Liver enzyme levels (GGT or alanine aminotransferase, ALT) were elevated in 64% of the patients, but the levels did not associate with the markers reflecting the severity of the disease. Serum amylase activities at the convalescent stage were higher than those at the acute phase (p < 0.001). No cases with acute pancreatitis were found. In conclusion, our findings indicate that alcohol consumption does not seem to affect the clinical course of an acute PUUV infection.

Severity Biomarkers in Puumala Hantavirus Infection.

Annually, over 10,000 cases of hemorrhagic fever with renal syndrome (HFRS) are diagnosed in Europe. Puumala hantavirus (PUUV) causes most of the European HFRS cases. PUUV causes usually a relatively mild disease, which is rarely fatal. However, the severity of the infection varies greatly, and factors affecting the severity are mostly unrevealed. Host genes are known to have an effect. The typical clinical features in PUUV infection include acute kidney injury, thrombocytopenia, and increased vascular permeability. The primary target of hantavirus is the endothelium of the vessels of different organs. Although PUUV does not cause direct cytopathology of the endothelial cells, remarkable changes in both the barrier function of the endothelium and the function of the infected endothelial cells occur. Host immune or inflammatory mechanisms are probably important in the development of the capillary leakage. Several immunoinflammatory biomarkers have been studied in the context of assessing the severity of HFRS caused by PUUV. Most of them are not used in clinical practice, but the increasing knowledge about the biomarkers has elucidated the pathogenesis of PUUV infection.

Glycoprotein YKL-40 Is Elevated and Predicts Disease Severity in Puumala Hantavirus Infection.

Most cases of hemorrhagic fever with renal syndrome (HFRS) in Europe are caused by the Puumala hantavirus (PUUV). Typical features of the disease are increased vascular permeability, acute kidney injury (AKI), and thrombocytopenia. YKL-40 is an inflammatory glycoprotein involved in various forms of acute and chronic inflammation. In the present study, we examined plasma YKL-40 levels and the associations of YKL-40 with disease severity in acute PUUV infection. A total of 79 patients treated in Tampere University Hospital during 2005-2014 were studied. Plasma YKL-40 was measured in the acute phase, the recovery phase, and one year after hospitalization. Plasma YKL-40 levels were higher during the acute phase compared to the recovery phase and one year after hospitalization (median YKL-40 142 ng/mL, range 11-3320, vs. 45 ng/mL, range 15-529, vs. 32 ng/mL, range 3-213, p < 0.001). YKL-40 level was correlated with the length of hospital stay (r = 0.229, p = 0.042), the levels of inflammatory markers-that is, blood leukocytes (r = 0.234, p = 0.040), plasma C-reactive protein (r = 0.332, p = 0.003), and interleukin-6 (r = 0.544, p < 0.001), and maximum plasma creatinine level (r = 0.370, p = 0.001). In conclusion, plasma YKL-40 levels were found to be elevated during acute PUUV infection and correlated with the overall severity of the disease, as well as with the degree of inflammation and the severity of AKI.

High plasma resistin associates with severe acute kidney injury in Puumala hantavirus infection.

BACKGROUND: Puumala hantavirus (PUUV) infected patients typically suffer from acute kidney injury (AKI). Adipokines have inflammation modulating functions in acute diseases including AKI. We examined plasma levels of three adipokines (resistin, leptin, and adiponectin) in acute PUUV infection and their associations with disease severity. METHODS: This study included 79 patients hospitalized due to acute PUUV infection. Plasma resistin, leptin, adiponectin, as well as IL-6 and CRP, were measured at the acute phase, recovery phase and one year after hospitalization. RESULTS: Plasma resistin levels were significantly higher in the acute phase compared to the recovery phase and one year after (median resistin 28 pg/mL (11-107) vs. 17 pg/mL (7-36) vs. 14 pg/mL (7-31), p<0.001). Maximum resistin concentration correlated with maximum plasma creatinine levels (r = 0.63; p<0.001). The higher the amount of albuminuria in the urine dipstick test (0-1+, 2+ or 3+) at admission, the higher the median of maximum resistin (24.7 pg/mL, 25.4 pg/mL and 39.6 pg/mL, respectively, p = 0.002). High resistin was also an independent risk factor for severe AKI (creatinine ≥353.6µmol/L) (OR 1.08, 95% CI 1.02-1.14). Neither plasma leptin nor adiponectin level had any correlation with creatinine concentration or the amount of albuminuria. CONCLUSIONS: Plasma resistin independently associates with the severity of AKI in acute PUUV infection. The association of resistin with the amount of albuminuria suggests that the level of plasma resistin is not only influenced by renal clearance but could have some role in the pathogenesis of AKI during PUUV infection.

Haematuria is a marker for the severity of acute kidney injury but does not associate with thrombocytopenia in acute Puumala hantavirus infection.

BACKGROUND: Puumala hantavirus (PUUV) causes haemorrhagic fever with renal syndrome characterized by thrombocytopenia, capillary leakage and acute kidney injury (AKI) with proteinuria and haematuria. Although the typical histologic lesion is acute tubulointerstitial nephritis, the amount of glomerular proteinuria predicts the severity of upcoming AKI. Here, we studied the associations of haematuria and proteinuria with the severity of emerging AKI, thrombocytopenia and markers of coagulation and fibrinolysis in PUUV infection. METHODS: We examined 205 consecutive patients treated for serologically confirmed acute PUUV infection at Tampere University Hospital during 1997-2014. The patients were divided into three groups according to the combined positive result in urine haemoglobin and albumin dipstick tests: 0-2 + (n = 58), 3-4 + (n = 100) and 5-6 + (n = 47). RESULTS: The medians of maximum creatinine concentrations in the three groups were: 0-2 + 100 µmol/L (range 52-1499), 3-4 + 204 µmol/L (range 65-1071) and 5-6 + 361 µmol/l (range 51-1285) (p < .001). The number of blood platelets (p = .069), and the levels of fibrinogen, prothrombin fragments F1 + 2 and d-dimer (p = .602, p = .113, p = .289, respectively) were not significantly different between the groups. When the amount of haematuria in the dipstick test was examined separately, no association with thrombocytopenia was detected (p = .307 between groups 0, 1+ and 2-3+). CONCLUSIONS: Combined positive result of haematuria and proteinuria in the dipstick test at hospital admission predicted the severity of upcoming AKI in acute PUUV infection. As haematuria was not associated with the severity of thrombocytopenia, it did not indicate increased bleeding tendency, but was rather a marker of acute kidney injury.

Glomerular Proteinuria Predicts the Severity of Acute Kidney Injury in Puumala Hantavirus-Induced Tubulointerstitial Nephritis.

BACKGROUND: Puumala virus (PUUV)-induced hemorrhagic fever with renal syndrome is common in many European countries. The typical renal histologic lesion is acute tubulointerstitial nephritis. We examined the type and kinetics of urine protein excretion and prognostic significance of proteinuria for the severity of acute kidney injury (AKI) in acute PUUV infection. METHODS: The amount of dipstick albuminuria at hospital admission was analyzed in 205 patients with acute PUUV infection. Dipstick albuminuria at admission was graded into 3 categories: 0-1+, 2+, and 3+. In 70 patients, 24-h urinary excretion of protein, overnight urinary excretion of albumin, immunoglobulin (Ig) G, and α1-microglobulin also were measured over 3 consecutive days during the hospital stay. RESULTS: Maximum median daily proteinuria, overnight albuminuria, and IgG excretion were observed over 5 days, while that of creatinine values was observed 9 days after the onset of the disease. The medians of maximum plasma creatinine levels during hospital stay were different in the 3 categories of dipstick albuminuria: 0-1+: 98 µmol/L (58-1,499), 2+: 139 µmol/L (71-829), and 3+: 363 µmol/L (51-1,285; p < 0.001). Dipstick albuminuria ≥2+ at admission could be detected in 89% of the patients who subsequently developed severe AKI. Glomerular proteinuria, but not tubular proteinuria (α1-microglobulin), correlated with the severity of the emerging AKI. CONCLUSION: In acute PUUV infection, maximum median proteinuria values preceded the most severe phase of AKI by a few days. A highly useful finding for clinical work was that a quick and simple albuminuria dipstick test at hospital admission predicted the severity of the upcoming AKI.

Thrombocytopenia associates with the severity of inflammation and variables reflecting capillary leakage in Puumala Hantavirus infection, an analysis of 546 Finnish patients.

BACKGROUND: Hantaviruses cause hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS) in humans. Hantavirus infections are characterized by thrombocytopenia. Our objective was to assess the association of thrombocytopenia with disease severity in HFRS induced by Puumala hantavirus (PUUV). METHODS: Altogether 546 patients treated for acute serologically confirmed PUUV infection during 1982-2013 at Tampere University Hospital, Finland, were examined. Blood platelet count was determined daily and analysed in relation to different variables reflecting disease severity. The patients were divided into two groups according to the minimum platelet count: severe thrombocytopenia (<69 × 10(9)/L, i.e. below median) and no severe thrombocytopenia (≥69 × 10(9)/L). RESULTS: Thrombocytopenia (platelet count <150 × 10(9)/L) was detected in 90% of patients, and in 28% of patients platelet count was <50 × 10(9)/L. Patients with severe thrombocytopenia had longer stay (8 versus 7 days, p = 0.002) and greater weight gain (2.8 versus 2.0 kg, p < 0.001) at the hospital, higher blood leukocyte count (11.2 × 10(9)/L versus 9.6 × 10(9)/L, p < 0.001), plasma C-reactive protein (81 versus 59 mg/L, p < 0.001), maximum hematocrit (0.44 versus 0.42, p < 0.001), urinary protein excretion (1.7 versus 1.1 g/24 h, p = 0.002), and lower plasma albumin concentration (27 versus 32 g/L, p < 0.001) than patients without severe thrombocytopenia (comparisons between medians). Maximum creatinine concentration did not differ between patients with or without severe thrombocytopenia (median 235 versus 214 µmol/L, p = 0.217). CONCLUSIONS: The severity of thrombocytopenia associates with the degree of inflammation and variables reflecting capillary leakage, but not with the severity of acute kidney injury in PUUV infected Finnish patients.

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

BACKGROUND: Puumala hantavirus (PUUV) induces an acute tubulointerstitial nephritis and acute kidney injury (AKI). Our aim was to evaluate the prognosis of severe AKI associated with PUUV infection. METHODS: We examined 556 patients who were treated at Tampere University Hospital during 1982-2013 for acute, serologically confirmed PUUV infection. Plasma creatinine was measured during hospitalization, convalescence, and 1, 2, and 5 years after the acute infection. RESULTS: Plasma creatinine concentration was elevated (>100 µmol/l) in 459 (83%) patients, while altogether 189 patients (34%) had severe AKI defined as Kidney Disease: Improving Global Outcomes (KDIGO) stage 3, that is, plasma creatinine ≥353.6 µmol/l (4.0 mg/dl) or need of dialysis. There were no fatal cases during the hospitalization or the following 3 months. Fatality rate during the years following PUUV infection did not differ between patients who had suffered from severe AKI versus those without severe AKI. Post-hospitalization plasma creatinine values were available for 188 (34%) patients. One month after the acute infection, patients with prior severe AKI had higher median plasma creatinine concentration (82 µmol/l, range 54-184) than patients without severe AKI (74 µmol/l, range 55-109, p = 0.005). After 1 year, no significant difference existed in median plasma creatinine concentrations between patients with (71 µmol/l, range 36-123) and without prior severe AKI (72 µmol/l, range 34-116, p = 0.711). After 5 years all but 1 patient had normal creatinine levels. CONCLUSIONS: In contrast to the worldwide well-accepted KDIGO criteria, severe AKI associated with PUUV infection is not associated with excess fatality but has a very good prognosis, both in the short and long terms.

Plasma pentraxin-3 and coagulation and fibrinolysis variables during acute Puumala hantavirus infection and associated thrombocytopenia.

Thrombocytopenia and altered coagulation characterize all hantavirus infections. To further assess the newly discovered predictive biomarkers of disease severity during acute Puumala virus (PUUV) infection, we studied the associations between them and the variables reflecting coagulation, fibrinolysis and endothelial activation. Nineteen hospital-treated patients with serologically confirmed acute PUUV infection were included. Acutely, plasma levels of pentraxin-3 (PTX3), cell-free DNA (cf-DNA), complement components SC5b-9 and C3 and interleukin-6 (IL-6) were recorded as well as platelet ligands and markers of coagulation and fibrinolysis. High values of plasma PTX3 associated with thrombin formation (prothrombin fragments F1+2; r = 0.46, P = 0.05), consumption of platelet ligand fibrinogen (r = -0.70, P < 0.001) and natural anticoagulants antithrombin (AT) (r = -0.74, P < 0.001), protein C (r = -0.77, P < 0.001) and protein S free antigen (r = -0.81, P < 0.001) and a decreased endothelial marker ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 domain 13) (r = -0.48, P = 0.04). Plasma level of AT associated with C3 (r = 0.76, P < 0.001), IL-6 (r = -0.56, P = 0.01) and cf-DNA (r = -0.47, P = 0.04). High cf-DNA coincided with increased prothrombin fragments F1+2 (r = 0.47, P = 0.04). Low C3 levels reflecting the activation of complement system through the alternative route predicted loss of all natural anticoagulants (for protein C r = 0.53, P = 0.03 and for protein S free antigen r = 0.64, P = 0.004). Variables depicting altered coagulation follow the new predictive biomarkers of disease severity, especially PTX3, in acute PUUV infection. The findings are consistent with the previous observations of these biomarkers also being predictive for low platelet count and underline the cross-talk of inflammation and coagulation systems in acute PUUV infection.

Plasma levels of soluble urokinase-type plasminogen activator receptor associate with the clinical severity of acute Puumala hantavirus infection.

OBJECTIVES: Urokinase-type plasminogen activator receptor is a multifunctional glycoprotein, the expression of which is increased during inflammation. It is known to bind to ß3-integrins, which are elementary for the cellular entry of hantaviruses. Plasma soluble form of the receptor (suPAR) levels were evaluated as a predictor of severe Puumala hantavirus (PUUV) infection and as a possible factor involved in the pathogenesis of the disease. DESIGN: A single-centre prospective cohort study. SUBJECTS AND METHODS: Plasma suPAR levels were measured twice during the acute phase and once during the convalescence in 97 patients with serologically confirmed acute PUUV infection using a commercial enzyme-linked immunosorbent assay (ELISA). RESULTS: The plasma suPAR levels were significantly higher during the acute phase compared to the control values after the hospitalization (median 8.7 ng/ml, range 4.0-18.2 ng/ml vs. median 4.7 ng/ml, range 2.4-12.2 ng/ml, P<0.001). The maximum suPAR levels correlated with several variables reflecting the severity of the disease. There was a positive correlation with maximum leukocyte count (r = 0.475, p<0.001), maximum plasma creatinine concentration (r = 0.378, p<0.001), change in weight during the hospitalization (r = 0.406, p<0.001) and the length of hospitalization (r = 0.325, p = 0.001), and an inverse correlation with minimum platelet count (r = -0.325, p = 0.001) and minimum hematocrit (r = -0.369, p<0.001). CONCLUSION: Plasma suPAR values are markedly increased during acute PUUV infection and associate with the severity of the disease. The overexpression of suPAR possibly activates ß3-integrin in PUUV infection, and thus might be involved in the pathogenesis of the disease.

Plasma cell-free DNA levels are elevated in acute Puumala hantavirus infection.

INTRODUCTION: Puumala hantavirus (PUUV) causes a hemorrhagic fever with renal syndrome called nephropathia epidemica (NE). The aim of the present study was to evaluate plasma cell-free DNA (cf-DNA) levels and urinary cf-DNA excretion in acute NE as well as their associations with the severity of the disease. METHODS: Total plasma cf-DNA was quantified directly in plasma of 61 patients and urine of 20 patients with acute NE. We also carried out a qualitative high-sensitivity lab-on-a-chip DNA assay in 20 patients to elucidate the appearance of cf-DNA in plasma and urine. RESULTS: The maximum plasma cf-DNA values taken during acute NE were significantly higher than the control values taken after the hospitalization period (median 1.33 µg/ml, range 0.94-3.29 µg/ml vs. median 0.77 µg/ml, range 0.55-0.99 µg/ml, P<0.001). The maximum plasma cf-DNA levels correlated positively with maximum blood leukocyte count (r = 0.388, P = 0.002) and the length of hospital stay (r = 0.376, P = 0.003), and inversely with minimum blood platelet count (r = -0.297, P = 0.020). Qualitative analysis of plasma cf-DNA revealed that in most of the patients cf-DNA displayed a low-molecular weight appearance, corresponding to the size of apoptotic DNA (150-200 bp). The visually graded maximum cf-DNA band intensity correlated positively with the maximum quantity of total plasma cf-DNA (r = 0.513, P = 0.021). Maximum urinary excretion of cf-DNA in turn was not markedly increased during the acute phase of NE and did not correlate with any of the variables reflecting severity of the disease or with the maximum plasma cf-DNA level. CONCLUSIONS: The plasma levels of cf-DNA are elevated during acute PUUV infection and correlate with the apoptotic cf-DNA-band intensity. The plasma cf-DNA concentration correlates with some variables reflecting the severity of the disease. The urinary excretion of cf-DNA does not reflect the degree of inflammation in the kidney.

High activity of indoleamine 2,3-dioxygenase is associated with renal insufficiency in Puumala hantavirus induced nephropathia epidemica.

Nephropathia epidemica (NE) is a hemorrhagic fever with renal syndrome caused by Puumala hantavirus. The severity of NE varies greatly. The aim of the present study was to evaluate whether serum indoleamine 2,3-dioxygenase (IDO) activity is associated with the severity of NE. A prospectively collected cohort of 102 consecutive patients with acute serologically confirmed NE was examined. Serum kynurenine, tryptophan, creatinine, CRP, and blood cell count were measured for up to 5 consecutive days after admission. The kynurenine to tryptophan (kyn/trp) ratio reflecting IDO activity was calculated. A maximum kyn/trp ratio >202 µmol/mmol had a sensitivity of 85% and a specificity of 75% for detecting maximum serum creatinine values >250 µmol/L by receiver operating characteristic (ROC) analysis. A maximum kyn/trp ratio >202 µmol/mmol (high IDO level) was also associated with other parameters reflecting the severity of the disease and renal impairment. Patients with high IDO levels had higher maximum serum creatinine (379 vs. 102 µmol/L, P<0.001), plasma C-reactive protein (104.1 vs. 72.1 mg/L, P=0.029), and blood leukocyte values (11.9 vs. 9.0 × 10(9) /L, P<0.001) compared to patients with kyn/trp ratio ≤ 202 µmol/mmol. They also had lower minimum urinary output (1,100 vs. 1,900 ml/day, P<0.001) and longer hospital stays (8 vs. 5 days, P<0.001). In conclusion, high serum IDO activity was associated with increased disease severity and renal impairment in NE.

The severity of Puumala hantavirus induced nephropathia epidemica can be better evaluated using plasma interleukin-6 than C-reactive protein determinations.

BACKGROUND: Nephropathia epidemica (NE) is a Scandinavian type of hemorrhagic fever with renal syndrome caused by Puumala hantavirus. The clinical course of the disease varies greatly in severity. The aim of the present study was to evaluate whether plasma C-reactive protein (CRP) and interleukin (IL)-6 levels associate with the severity of NE. METHODS: A prospectively collected cohort of 118 consecutive hospital-treated patients with acute serologically confirmed NE was examined. Plasma IL-6, CRP, and creatinine, as well as blood cell count and daily urinary protein excretion were measured on three consecutive days after admission. Plasma IL-6 and CRP levels higher than the median were considered high. RESULTS: We found that high IL-6 associated with most variables reflecting the severity of the disease. When compared to patients with low IL-6, patients with high IL-6 had higher maximum blood leukocyte count (11.9 vs 9.0 x 10(9)/l, P = 0.001) and urinary protein excretion (2.51 vs 1.68 g/day, P = 0.017), as well as a lower minimum blood platelet count (55 vs 80 x 10(9)/l, P < 0.001), hematocrit (0.34 vs 0.38, P = 0.001), and urinary output (1040 vs 2180 ml/day, P < 0.001). They also stayed longer in hospital than patients with low IL-6 (8 vs 6 days, P < 0.001). In contrast, high CRP did not associate with severe disease. CONCLUSIONS: High plasma IL-6 concentrations associate with a clinically severe acute Puumala hantavirus infection, whereas high plasma CRP as such does not reflect the severity of the disease.