Ilpo Ala-Houhala

Human Leukocyte Antigen–B8-DR3 Is a More Important Risk Factor for Severe Puumala Hantavirus Infection than the Tumor Necrosis Factor–α(−308) G/A Polymorphism

The tumor necrosis factor (TNF)-alpha(-308) G/A polymorphism (TNF-2) is in linkage disequilibrium with the human leukocyte antigen (HLA)-B8-DR3 haplotype. Both factors have been associated with severe Puumala hantavirus-induced nephropathia epidemica (NE). To examine which part of this extended haplotype might show the strongest association with the outcome of NE, the HLA-B, HLA-DRB1, and TNF-alpha(-308) alleles in 116 hospital-treated patients with NE were analyzed. The findings pointing to clinically severe NE were strongly associated with HLA-B8-DR3 haplotype. There was a trend toward severe disease in persons positive for TNF-2. This was probably due to strong linkage disequilibrium with HLA-B8-DR3, since there were no differences in the clinical severity of NE when TNF-2-positive/B8-DR3-negative persons were compared with TNF-2-negative/B8-DR3-negative persons. It is concluded that the HLA-B8-DR3 haplotype is an important contributor to the course of NE. The data indicate that the TNF-2 allele is not an independent risk factor for severe NE but a passive component in the extended haplotype.

Effect of Intravenous Calcitriol on Cardiac Systolic and Diastolic Function in Patients on Hemodialysis

The systolic and diastolic function of the heart of hemodialysis (HD) patients and the effect of intravenous vitamin D therapy on cardiac function was studied by Doppler and digitized M-mode echocardiography in 10 HD patients before and after 3–4.5 months of calcitriol therapy. Calcitriol was administered intravenously 1–3 times a week at a dose of 1–2 µg after the dialysis sessions. Ten age- and sex-matched healthy controls were also examined echocardiographically. Before calcitriol therapy cardiac wall thicknesses (interventricular septum, posterior wall) and left ventricle (LV) dimensions (end diastolic, end systolic) were greater, and LV diastolic (peak late diastolic velocity, peak early diastolic velocity/peak late diastolic velocity ratio, isovolumic relaxation time) and systolic (fractional shortening) function was impaired in HD patients as compared to controls. The LV posterior wall thickness was related to plasma parathyroid hormone (PTH; r = 0.70, p = 0.01) in the patients. Calcitriol therapy raised serum ionized Ca from 1.23±0.04 to 1.33 ± 0.04 mmol/l and reduced PTH from 41.1±10.7 to 34.2±11.7 pmol/l (29±11%). Calcitriol therapy did not cause any significant changes in cardiac function in the whole patient group. However, in a subgroup of 5 patients with severe but controllable hyperparathyroidism (PTH >3 times upper normal margin) the LV dimensions and systolic function improved (LV end systolic dimension from 39.0 ± 4.0 to 31.3 ± 2.9 mm, p = 0.03; LV end diastolic dimension from 57.7 ± 3.1 to 53.4 ± 3.0 mm, p = 0.06; fractional shortening from 33 ± 4 to 42 ± 3%, p = 0.03). The diastolic indices improved also, but not significantly. In conclusion, left ventricle hypertrophy and systolic and diastolic dysfunction was observed in HD patients. Intravenous calcitriol therapy improved cardiac function in patients with severe secondary hyperparathyroidism.

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

BackgroundNephropathia 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.MethodsA 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.ResultsWe 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 × 109/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 × 109/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.ConclusionsHigh 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.

Human CD8+ T cell memory generation in Puumala hantavirus infection occurs after the acute phase and is associated with boosting of EBV-specific CD8+ memory T cells.

The induction and maintenance of T cell memory is incompletely understood, especially in humans. We have studied the T cell response and the generation of memory during acute infection by the Puumala virus (PUUV), a hantavirus endemic to Europe. It causes a self-limiting infection with no viral persistence, manifesting as hemorrhagic fever with renal syndrome. HLA tetramer staining of PBMC showed that the CD8+ T cell response peaked at the onset of the clinical disease and decreased within the next 3 wk. Expression of activation markers on the tetramer-positive T cells was also highest during the acute phase, suggesting that the peak population consisted largely of effector cells. Despite the presence of tetramer-positive T cells expressing cytoplasmic IFN-γ, PUUV-specific cells producing IFN-γ in vitro were rare during the acute phase. Their frequency, as well as the expression of IL-7Rα mRNA and surface protein, increased during a follow-up period of 6 wk and probably reflected the induction of memory T cells. Simultaneously with the PUUV-specific response, we also noted in seven of nine patients an increase in EBV-specific T cells and the transient presence of EBV DNA in three patients, indicative of viral reactivation. Our results show that in a natural human infection CD8+ memory T cells are rare during the peak response, gradually emerging during the first weeks of convalescence. They also suggest that the boosting of unrelated memory T cells may be a common occurrence in human viral infections, which may have significant implications for the homeostasis of the memory T cell compartment.

Adequate Seroresponse to Influenza Vaccination in Dialysis Patients

Background: Hemodialysis (HD) patients are immunocompromised, and they have been shown to react suboptimally to recommended vaccinations. Advances in dialysis therapy and other supportive measures may theoretically result in better immune system functions. Clinical evidence supporting this theory has, however, not been presented. With influenza vaccination response, we tried to address this question. Methods: 42 HD and 15 continuous ambulatory peritoneal dialysis (CAPD) patients were vaccinated with a trivalent influenza vaccine, and the seroresponses at 5 weeks were measured. The results were compared with those of similarly vaccinated 20 nephrology outpatient clinic patients with varying degrees of renal insufficiency and those of 31 cardiac patients with normal renal function. Results: The dialysis patients had higher prevaccination titers of hemagglutination-inhibiting (HI) antibodies to all three vaccine virus antigens than the other groups due to more frequent previous vaccinations. The dialysis patients exhibited lower antibody increases, but an almost comparable proportion of them reached a protective antibody level (HI titers ≧40) 5 weeks after vaccination [A/H3N2: 61% (cardiac patients), 35% (nephrology outpatient clinic patients), 67% (CAPD), and 36% (HD); A/H1N1: 71, 70, 80 and 60; B: 97, 90, 80, and 76%, respectively]. Among the HD group, all patients receiving parenteral calcitriol except 1 (83%), but only 50% of the other HD patients produced protective antibody titers at least to two out of three vaccine virus antigens. No other patient- or HD treatment-associated parameter was significantly related to the vaccination-induced antibody response. Conclusions: We conclude that influenza vaccination of dialysis patients according to current recommendations may be effective. Additionally, our results suggest that parenteral calcitriol treatment may augment the immune response of HD patients even in a clinically relevant way, an effect so far shown only in in vitro studies.

Long-term Renal Dysfunction in Patients with Acute Urinary Retention

Objective: Acute urinary retention (AUR) causes bilateral renal obstruction, which has been found to affect kidney function. This study evaluated both glomerular and tubular renal function in the long term after the resolution of AUR. Material and methods: Renal function in 15 patients affected by AUR and found still to evince renal dysfunction 6 months afterwards was reevaluated approximately 18 months after the episode. The bladder outlet obstruction was treated and all patients voided normally at 6 month control. Results:OBJECTIVE Acute urinary retention (AUR) causes bilateral renal obstruction, which has been found to affect kidney function. This study evaluated both glomerular and tubular renal function in the long term after the resolution of AUR. MATERIAL AND METHODS Renal function in 15 patients affected by AUR and found still to evince renal dysfunction 6 months afterwards was re-evaluated approximately 18 months after the episode. The bladder outlet obstruction was treated and all patients voided normally at 6 month control. RESULTS The percentage of patients suffering from lowered creatinine clearance and elevated alpha1-microglobulin excretion increased during follow-up from AUR up to 6 and 18 months (46% to 57% to 79% and 42% to 71% to 100%, respectively). In addition, daily protein excretion was abnormally high in 69% of patients at the 18 month follow-up. In most cases the abnormalities found in renal function were mild. CONCLUSION Patients evincing renal dysfunction 6 months after AUR showed permanent impairment in tubular function, whereas glomerular permeability had partially recovered. Although this may be explained in part by chronic obstruction prior to AUR and although the impairment was mild in most cases, these findings stress the importance of urgent treatment of AUR to avoid the development of renal failure.

More than half of the patients with acute Puumala hantavirus infection have abnormal cardiac findings

This study was conducted to determine the frequency, severity and outcome of cardiac findings in patients with acute Puumala hantavirus-induced nephropathia epidemica (NE). 70 consecutive, hospital-treated patients with serologically confirmed NE were prospectively examined using serial electrocardiograms (ECG), plasma troponin I, tumour necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and echocardiography (ECHO). Examinations were repeated after 3 and 12 months. ECG changes were observed in 57% of patients. Plasma troponin I levels remained normal in all. In six patients, ECHO showed left ventricular contraction abnormalities, and 1 patient had mild pericardial effusion. There were no differences in clinical or standard laboratory findings or in plasma TNF-α and IL-6 concentrations between patients with and without ECG or ECHO changes. During the follow-up, all acute-phase changes in ECG and ECHO reverted to normal, which probably reflects their benign nature. We conclude that abnormal cardiac findings are surprisingly common during NE.

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 × 109/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. J. Med. Virol. 83:731–737, 2011.

Tubular proteinuria and glomerular filtration 6 years after puumala hantavirus-induced acute interstitial nephritis.

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.

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

Background/Aims: We have found greater urinary protein excretion and higher glomerular filtration rate (GFR) and blood pressure in patients 6 years after acute nephropathia epidemica (NE) compared with seronegative controls. The present aim was to establish whether the long-term outcome is determined by the severity of acute illness. Methods: Serial plasma interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α), creatinine, C-reactive protein, blood cell count as well as 24-hour urinary protein and overnight α1-microglobulin and albumin excretions were measured in 37 patients with acute NE. Human leucocyte antigen (HLA)-B, HLA-DRB1, TNF-α(–308) and IL-6(–174) alleles were also analyzed. After 6 years, GFR, blood pressure and urinary protein excretion were examined. Results: There were no associations between the clinical severity of acute NE or the genetic factors determined and the increased GFR, hypertension or 24-hour urinary protein excretion observed 6 years later. The degree of inflammation during the acute phase was higher in patients who had increased urinary excretion of α1-microglobulin 6 years later compared with those with no α1-microglobulin excretion. Conclusion: Neither the severity of acute NE nor the host genetic factors determined the predicted renal function, blood pressure or 24-hour urinary protein excretion 6 years later.