Yukihiko Kawasaki

Genetic diversity of enterovirus 71 associated with hand, foot, and mouth disease epidemics in Japan from 1983 to 2003

Background: Enterovirus 71 (EV71) is one of the major etiologic agents of hand, foot and mouth disease (HFMD). The surveillance data indicate that EV71 infection follows an epidemic mode of transmission, causing large outbreaks and then becoming quiescent for a few years. Methods: We investigated the genetic diversity of a total of 121 EV71 strains isolated from patients with HFMD in Fukushima, Japan, from 1983 to 2003 and compared their genetic relation with the 164 EV71 strains isolated in the world using phylogenetic analysis based on the VP4 sequence. Results: We observed EV71-related HFMD outbreaks in Fukushima in 1984, 1987, 1990, 1993, 1997, 2000 and 2003. Phylogenetic reconstruction of EV71 strains isolated in Fukushima demonstrated 8 genetically distinct clusters, including 6 subgroups previously designated as B-1, B-2 and 3, B-4, C-1, C-2, and C-3 and 2 subgroups newly designated as B-5 and C-4. Additional 2 indistinct clusters belonged to genogroup C and were named C-U1 and C-U2. Of those subgroups, B-1, C-U1, C-U2, C-2, B4, and C-4 and B-5 dominantly related to epidemics that occurred in the years 1984, 1987 and 1990, 1993, 1997, 2000 and 2003, respectively. EV71 strains derived from each outbreak in Fukushima formed a single cluster with those isolated during almost the same time period in other area of Japan and in other countries. Conclusions: Our results suggested that the repeated EV71 outbreaks might be the result of the worldwide transmission of the newly introduced genetically divergent EV71 strains.

Mizoribine: a new approach in the treatment of renal disease.

Mizoribine (MZB) is an imidazole nucleoside and an immunosuppressive agent. The immunosuppressive effect of MZB has been reported to be due to the inhibition of DNA synthesis in the S phase of the cell cycle. Because of its relative lack of toxicity, during the past decade MZB has been frequently used instead of azathioprine as a component of immunosuppressive drug regimens. MZB is being used to treat renal transplantation patients, IgA nephropathy, lupus erythematosus, and childhood nephrotic syndrome (NS), and some recent studies have assessed the efficacy of oral MZB pulse therapy for severe lupus nephritis, steroid-resistant NS, and frequently relapsing-steroid-dependent NS. This review summarizes the published findings on the efficacy of MZB for renal disease including IgA nephropathy, lupus nephritis, and NS, as well as of oral MZB pulse therapy for severe lupus nephritis and NS, and also the mechanism of the effect of oral MZB pulse therapy on the lymphocyte cell cycle.

Genetic Diversity of Coxsackievirus A16 Associated with Hand, Foot, and Mouth Disease Epidemics in Japan from 1983 to 2003

ABSTRACT To clarify the chronologic genetic diversity of coxsackievirus A16 (CV-A16) strains associated with hand, foot, and mouth disease (HFMD) epidemics in a restricted area and their genetic relation with those isolated in other areas, we investigated the genetic diversity of the 129 CV-A16 strains associated with HFMD epidemics in Fukushima, Japan, from 1983 to 2003, and compared their genetic relation to 49 CV-A16 strains isolated in other areas of Japan and in China by using phylogenetic analysis based on the VP4 sequences. Phylogenetic reconstruction of the CV-A16 strains isolated in Fukushima from 1983 to 2003 demonstrated three distinct genetically divergent clusters related to HFMD epidemics that occurred from 1984 to 1994 (including the 1985 and 1991 outbreaks), HFMD epidemics from 1987 to 1998 (including the 1988 and 1998 outbreaks), and HFMD epidemics from 1995 to 2003 (including the 1995 and 2002 outbreaks). CV-A16 strains isolated during each period in Fukushima formed a single cluster with those isolated during essentially the same time period in other areas of Japan and in China. Our results demonstrated that prevalent CV-A16 strains causing HFMD in Fukushima, Japan, genetically changed twice during 21 epidemics, and changes were also observed in the CV-A16 strains causing HFMD epidemics in other areas. We concluded that repeated outbreaks of CV-A16-related HFMD in Japan were caused, in part, by the introduction of genetically changed CV-A16 strains, which might be transmitted overseas.

Correlation between serum interleukin 6 and C-reactive protein concentrations in patients with adenoviral respiratory infection.

Objective. To characterize adenoviral respiratory infection, we evaluated clinical features, laboratory findings and serum cytokine concentrations in patients with adenoviral infection and compared them with those in patients with influenza virus and respiratory syncytial virus (RSV) infections. Methods. We enrolled 106 patients who had been diagnosed with acute viral respiratory infection caused by adeno-, influenza and respiratory syncytial viruses from January, 1995, through December, 1998. Forty-nine patients had adenovirus infection, 19 patients had influenza virus infection and 38 patients had RSV infection. Etiologic diagnosis was made based on the antigen detection by enzyme immunoassay (influenza virus, RSV), and viral isolation was done by tissue culture (adenovirus, influenza virus) from nasopharyngeal specimens. We evaluated clinical manifestations, laboratory findings (white blood cell count, C-reactive protein, erythrocyte sedimentation rate) and serum cytokine [interleukin (IL)-1-beta, IL-6, IL-8, interferon gamma and tumor necrosis factor alpha] concentrations. Results. We observed prolonged fever, strong inflammatory response such as leukocytosis with neutrophilia and high C-reactive protein values in patients with adenoviral respiratory infection compared with those in patients with influenza virus and RSV infections. Serum IL-6 concentrations in patients with adenoviral respiratory infection were higher than those in patients with influenza virus and RSV infections. Other cytokine (IL-1-beta, IL-2, interferon gamma and tumor necrosis factor alpha) values did not differ among adenovirus, influenza virus and RSV infections. Conclusions. Patients with adenoviral respiratory infection have high grade and prolonged fever, strong inflammatory response and higher serum IL-6 than in influenza and RSV infection.

Cytochrome c and tumor necrosis factor-alpha values in serum and cerebrospinal fluid of patients with influenza-associated encephalopathy

Cytochrome c and tumor necrosis factor-α concentrations were measured in serum and cerebrospinal fluid samples from 10 patients with influenza-associated encephalopathy. In the acute exacerbation phase, serum tumor necrosis factor-α and cytochrome c values were high in patients with a poor prognosis. In the convalescent phase, cerebrospinal fluid cytochrome c values increased remarkably in patients with subsequent brain atrophy.

Clinicopathological features and the prognosis of IgA nephropathy in Japanese children on long-term observation.

AIMS Clinicopathological features were investigated to clarify the ultimate prognosis and prognostic indicators for patients with IgA nephropathy in Japanese children. METHODS We evaluated the outcomes of 181 patients in whom IgA nephropathy was diagnosed before the age of 15 years since September 1979 and followed-up at least for three years with regard to clinical data at the onset of symptoms and renal histologic data. RESULTS After mean follow-up of 7.3 years from onset, 91 patients of 181 (50.3%) were in clinical remission at the last examination, 24 (13.2%) had isolated hematuria, 59 (32.6%) had hematuria and proteinuria. Eighteen of 59 (9.9%) had proteinuria more than 1 g per 24 hours. Hypertension was observed in 12 cases and 7 (3.9%) developed end-stage renal disease. Except 7, no patient had reduced renal function and elevated serum creatinine at the final follow-up. Predicted renal survival rate from onset was 92.3% at 10 years and 89.1% at 20 years. In multivariable analysis, age at onset and chronic changes of tubulointerstitium were associated with poor outcome. CONCLUSIONS Of 181 children with IgA nephropathy, 50% regressed, remaining 46% had hematuria and/or proteinuria and 4% of patients lapsed into end-stage renal disease. Our results indicate that childhood IgA nephropathy has a benign course and the risk for end-stage renal disease is lower than that of adults. Age at onset and tubulointerstitial lesions were the strong predictors of a progressive course of childhood IgA nephropathy.

The pathogenesis and treatment of pediatric Henoch–Schönlein purpura nephritis

Henoch–Schönlein purpura (HSP) is a systemic disorder characterized by leukocytoclastic vasculitis involving the capillaries and the deposition of IgA immune complexes. Renal involvement is the principal cause of morbidity and mortality in children with HSP. Thus, it is important to clarify the onset mechanism of Henoch–Schönlein purpura nephritis (HSPN) and to identify the most appropriate treatment. We herein review the pathogenesis and treatment of HSPN. As to the pathogenesis, several studies suggest that galactose-deficient IgA1 is recognized by anti-glycan antibodies, leading to the formation of circulating immune complexes and their mesangial deposition, thereby inducing renal injury. Aggressive therapies for the treatment of severe HSPN, including multiple drug combination therapy and plasmapheresis, have been shown to be effective in ameliorating proteinuria and histological severity. Nevertheless, detailed investigations of the pathogenesis of HSPN and double-blind randomized control studies on children with HSPN are still necessary.

Efficacy of Prednisolone and Mizoribine Therapy for Diffuse IgA Nephropathy

Objective: There have been only a few studies concerning oral prednisolone and mizoribine therapy for diffuse IgA nephritis (IgAN). We evaluated the efficacy of prednisolone and mizoribine therapy for diffuse IgAN. Methods: We enrolled 34 patients who had been diagnosed as having diffuse IgAN with severe proteinuria during the period from 1992 to 1999. Following diagnostic renal biopsy, the patients were treated with prednisolone, mizoribine, warfarin and dilazep dihydrochloride. The clinical features, laboratory data and pathological findings between pre- and post-therapy were investigated. Results: The mean urinary protein excretion after 6 months of treatment had decreased significantly compared to pre-therapy. The incidence of hematuria in post-therapy was lower than that of pre-therapy. The grading index decreased significantly from 4.8 ± 2.1 at the first biopsy to 2.3 ± 1.7 at the second biopsy (p < 0.001) and the staging index decreased significantly from 4.1 ± 1.9 at the first biopsy to 2.7 ± 2.4 at the second biopsy (p < 0.05). Macrophage infiltration and α-smooth muscle actin-positive cells in the glomerulus and interstitial region decreased significantly in post-therapy compared with pre-therapy. At the most recent follow-up, none of the 34 patients had renal insufficiency. Conclusions: Our study suggested that prednisolone and mizoribine therapy is effective for those patients with the risk of progression of IgAN.

Prognostic predictive values of serum cytochrome c , cytokines, and other laboratory measurements in acute encephalopathy with multiple organ failure

Aims: To evaluate the prognostic predictive values of cytochrome c, cytokines, and other laboratory measurements in serum collected during neurological onset in acute encephalopathy with multiple organ failure. Methods: In addition to general laboratory examinations, the concentrations of cytochrome c (apoptosis marker) and cytokines (inflammatory markers) were measured in serum samples collected at the initial phase in 29 patients with acute encephalopathy. The obtained values were evaluated as predictors for the development of severe encephalopathy. Results: Cytochrome c, tumour necrosis factor α (TNF-α), interleukin 6 (IL-6), soluble TNF-receptor 1 (sTNF-R1), and aspartate aminotransferase (AST) concentrations at the initial phase were high and correlated well with patient outcome. High concentrations of serum cytochrome c (>45 ng/ml), sTNF-R1 (>2000 pg/ml), AST (>58 IU/dl), IL-6 (>60 pg/ml), and TNF-α (>15 pg/ml) predicted an unfavourable prognosis (sequelae and death) at 93%, 79%, 82%, 77%, and 60%, respectively. The specificity of those markers was 100%, 89%, 83%, 100%, and 100%, respectively. Conclusions: Serum cytochrome c is the most sensitive and specific predictor for the development of severe encephalopathy at the initial phase. Results suggest that this marker might be used to guide decisions regarding the start of the initial treatment and further intensive care.

Rhinovirus load and disease severity in children with lower respiratory tract infections

It has not been clarified if there is a correlation between rhinovirus (RV) load and disease severity in the lower respiratory tract infections of hospitalized children. This study was undertaken to elucidate the contribution of the viral load to the development of disease severity in 412 children ≤3 years of age who were hospitalized with lower respiratory tract infections. The RV load in nasopharyngeal aspirates obtained from the patients at the time of admission was measured by real‐time quantitative reverse‐transcription polymerase chain reaction (PCR), and the clinical symptoms of the patients were assessed using a severity scoring system. Of the 412 patients, 43 (10.4%) were diagnosed with RV infections only, and 15 were determined to have high severity scores. When all patients infected with RV were assessed, there was no correlation between the viral load and the disease severity. However, there was a significant negative correlation between the disease severity and age among children <11 months of age (n = 15, ρ = −0.677, P = 0.006) and a significant positive correlation between the viral load and the disease severity among children ≥11 months of age (n = 28, ρ = 0.407, P = 0.032). Among the patients infected with RV <11 months of age, the disease severity may be associated with an immature immune response and the small diameter of their airways rather than viral load. By contrast, in the patients ≥11 months of age, viral load may contribute to the development of disease severity. J. Med. Virol. 84: 1135–1142, 2012.