Occurrence of hepatitis E virus infection in acute hepatitis in Thailand.

Hepatitis E virus (HEV) infection is one of the enterically transmitted types of hepatitis. The present study was undertaken to estimate the occurrence of HEV infection in sporadic acute hepatitis in Thailand. Serum samples were obtained from 614 suspected acute hepatitis patients at two large hospitals in Bangkok during 2008, 2009, and 2011. Acute hepatitis E was identified by the presence of anti-HEV IgM (4.8%) using indirect ELISA kits and/or HEV RNA (4.5%) by a semi-nested reverse transcription-polymerase chain reaction assay. HEV IgM was the most common marker for detection (77%) at diagnosis, either by positive HEV IgM alone or together with HEV RNA, whereas HEV RNA alone was detected in 23% of patients. Overall, 4.2% of cases (26 out of 614) were acute HEV infection with the highest attack rate in the elderly age group. In addition, nucleotide sequence analysis of five HEV samples revealed 92.8-99.8% homology. All viruses were clustered into HEV genotype 3 and were similar genetically to swine HEV strains previously detected in the same area. Therefore, the occurrence of HEV infection with closely related to swine genotype 3 was approximately 4-5% of acute hepatitis cases in Thailand. Anti-HEV IgM was the most common marker at diagnosis.

Surveillance of hepatitis A and E viruses contamination in shellfish in Thailand.

AIMS: To survey for hepatitis A virus (HAV) and hepatitis E virus (HEV) contamination in edible bivalve shellfish. METHODS AND RESULTS: A total of 213 shellfish (52 oysters, 69 cockles and 92 mussels) collected from a culture farm and two retailed markets were investigated for HAV and HEV contamination by reverse transcription-polymerase chain reaction (RT-PCR) assay using HA2-HA1 (capsid region) and HE366-HE363 (ORF2/3 overlapping region) primers, respectively. It was found that 3.8% of the shellfish and 2.9 and 6.5% of the cockle and mussel, respectively, showed positive for HAV detection. Nucleotide sequencing of all the 8 HAV-positive shellfish revealed 97-100% similarity to HAV subgenotype IA. Interestingly, viruses were found more frequently in the gills than in digestive tissue (4.5%vs 0.5%, P = 0.045). All the shellfish were negative for HEV. CONCLUSION: Significant contamination of HAV in edible bivalve shellfish was observed. Beside digestive tissue, gills are one of the important samples for viral genome detection. SIGNIFICANCE AND IMPACT OF THE STUDY: HAV-contaminated shellfish can play a role as reservoirs and/or vehicles in faecal-oral transmission in Thailand, and further monitoring of such a contamination is required.

Immunophenotypic discrepancies between granulocytic and erythroid lineages in peripheral blood of patients with paroxysmal nocturnal haemoglobinuria.

In paroxysmal nocturnal haemoglobinuria (PNH), somatic mutation of the PIG-A gene is thought to result in altered expression of glycosylphosphatidylinositol (GPI)-anchored proteins. This study was performed to determine if there were any heterogeneities of cellular phenotypes between two major peripheral blood cells, erythrocytes and granulocytes. Using CD59-based immunocytometry, the patterns of CD59 expression were shown to be conserved in the circulating erythroid cells (reticulocytes and mature erythrocytes) in all 29 patients with PNH. Twenty-one patients had distinct combinations of PNH type I, II, and III cells in different lineages. Only eight patients exhibited similar patterns of CD59 expression between the two lineages. Approximately one third of the patients had PNH type II cells in either or both of the two lineages indicating variable lineage involvement. The proportion of abnormal granulocytes was higher than those of abnormal reticulocytes and erythrocytes. In patients with appropriate erythropoietic responses to haemolysis (RPI > 2.0), shift reticulocytes display predominantly PNH phenotypes. These immature erythroid cells with altered expression of GPI-anchored proteins may dominate the peripheral blood during periods of increased marrow activity resulting in greater phenotypic mosaicism in such patients. Discrepancies in expression of GPI-anchored proteins in PNH which are highly variable between the two lineages may be the result of their different life spans and the influence of complement-mediated cytolysis. The phenomena also indicated the possible occurrence of more than one PNH clones with variable clonal dominance.

Role of FcgammaRI (CD64) in erythrocyte elimination and its up-regulation in thalassaemia.

To examine any role of the high affinity Fcgamma class I receptor (FcgammaRI) (CD64) in erythrocyte elimination by mononuclear phagocytes (MP) in thalassaemia (thal), we investigated the in vitro interaction of beta-thalassaemic erythrocytes with monocytes (Mo) whose FcgammaR expression had been modulated by cytokines. Treatment of Mo with interferon (IFN)-gamma or interleukin (IL)-10 which up-regulate FcgammaRI, caused a dose-dependent increase in binding of beta-thalassaemic erythrocytes, whereas stimulation with IL-4 which down-regulates the receptor, reduced this interaction, in a dose-dependent manner, to that of normal erythrocytes. Binding of thalassaemic erythrocytes by IFN-gamma or IL-10-treated Mo was inhibited by FcgammaRI-specific reagents. In addition, Mo expression of FcgammaRI and HLA class II DR was determined by flow cytometry in Thai patients with HbH disease (alpha1/alpha2 or alpha1/Hb Constant Spring) (n = 15) or beta degrees -thal/HbE (n = 16). In both groups of patients FcgammaRI expression was increased as compared to normal controls (n = 14): mean fluorescence intensity (+/-SD) 124.79 +/- 38. 77 in HbH disease and 121.86 +/- 18.23 in beta degrees -thal/HbE versus 91.94 +/- 17.36 in normal controls (P < 0.01 and P < 0.001, respectively). In contrast, HLA class II DR expression was similar in patients and controls. The results suggest that, in thalassaemia, up-regulated FcgammaRI on mononuclear phagocytes plays a role in their interaction with erythrocytes and that this process can be modified by cytokines.

Genotypic, immunophenotypic and clinical features of Thai patients with paroxysmal nocturnal haemoglobinuria.

Paroxysmal nocturnal haemoglobinuria (PNH) is an acquired haematological disorder characterized by complement-mediated haemolytic anaemia caused by deficiency of glycosylphosphatidylinositol (GPI) anchored proteins. Somatic mutation of an X-linked gene, PIG-A, is responsible for the defect in biosynthesis of GPI-anchor. It appears that frequency of PNH differs geographically, and seems to be more frequent in some Asian countries, such as Thailand and China. We studied a group of 34 Thai patients with PNH to see whether the somatic mutations in PIG-A, extent of deficiency of GPI-anchored proteins (complete or partial) and complication with aplastic anaemia among Thai patients are different from those in other regions. We determined 37 PIG-A mutations in 33 patients (10 base substitutions, 14 single-base deletions, five multiple-base deletions, three single-base insertions, two multiple base insertions and three others) which were found to be similar to those found in European, American and Japanese patients. Most patients had cells with a complete deficiency of CD59 (type III cells), whereas 19% and 33% of the patients with reliable data for CD59 expression had partially deficient granulocytes and erythrocytes (type II cells), respectively. Most mutations resulted in a complete loss of function of PIG-A in accordance with the prevalent PNH III phenotype. 19 patients (51%) had aplastic anaemia; their PIG-A mutations were not different from those without pre-existing aplastic anaemia. These characteristics of Thai patients are similar to patients from other regions. There was some negative correlation between mean basal Hb concentration and percentage of CD59-negative granulocytes (r = -0. 374; P = 0.0476). In addition, patients with severe anaemia (basal Hb <7 g/dl) had a significantly higher percentage of affected granulocytes than those with mild anaemia (88.5 +/- 9.4 v 64.9 +/- 25.9; P = 0.01). The data suggest that the severity of anaemia in PNH depends partly on the size of the PNH clone.

Serum levels of tumor necrosis factor-alpha, interleukin-1, and interferon-gamma in beta(o)-thalassemia/HbE and their clinical significance.

Serum levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-1alpha (IL-1alpha), and interferon-gamma (IFN-gamma) were estimated by conventional ELISA kits in 60, 42, and 58 Thai patients, respectively, with beta(o)-thalassemia HbE and found to be above the normal range in 13%, 21%, and 33% of the patients, respectively. Using high-sensitivity ELISA systems, an additional 10 beta(o)-thal/HbE patients were compared with 9 controls for concentrations of circulating TNF-alpha and IL-1beta, and 9 and 5 patients, respectively, but only 1 and none of the controls, respectively, showed values above the normal ranges. In patients with abnormally high IFN-gamma levels, basal hemoglobin values were significantly lower than in those with normal levels of the cytokine (mean +/- SEM: 6.03+/-0.24 vs. 7.08+/-0.18, p < 0.05), although circulating concentrations of soluble transferrin receptors (sTrF) and absolute reticulocyte counts were similar in the two groups. Patients with raised or normal levels of TNF-alpha, IL-1alpha, or IL-1beta had similar basal hemoglobin values. In a phagocytosis assay, monocytes of patients with raised serum levels of IFN-gamma showed significantly more attached or ingested IgG-coated red cells than those of patients with normal concentrations of the cytokine (mean +/- SEM: 192+/-22 vs. 140+/-14 per 100 monocytes, p < 0.05). Moreover, in 3 of 4 of the former patients, the number of attached or ingested IgG-coated red cells per 100 monocytes was above the 95% reference limit for the latter patients. The results suggest that IFN-gamma aggravates the anemia of beta(o)-thal/HbE by activating mononuclear phagocytes for destruction of red cells but not by inhibiting erythropoiesis. The elevated serum levels of TNF-alpha and IL-1 could contribute to complications of the disease, such as cachexia and thromboembolic phenomena.

Genotypic and phenotypic implications in paroxysmal nocturnal hemoglobinuria (PNH): a preliminary investigation.

The genetic and biochemical defects underlying paroxysmal nocturnal hemoglobinuria (PNH) have recently been elucidated. The deficiency of the surface expression of glycosylphosphatidylinositol (GPI)-anchored proteins caused by a somatic mutation of the PIG-A gene, an X-chromosomal gene that participates in the first step of the GPI anchor synthesis, has been shown to be responsible for PNH in all patients. The mutations of PIG-A studied to date are highly heterogeneous. They are however mainly of the frameshift type (61.5%). The characteristic abnormalities of PNH phenotypes has also been shown especially by DAF- and/or CD59-based fluorescent immunocytometry. A great degree of heterogeneity in the patterns and levels of expression of GPI-anchored proteins in various cell types was demonstrated indicating a discrepancy of lineage involvement. In this investigation, major blood cell populations, i.e erythrocytes and granulocytes were analyzed immunophenotypically, the mutations of PIG-A were identified by heteroduplex analysis and nucleotide sequencing and the consequences of PIG-A mutations were observed. All the mutations identified in 9 patients with PNH resulted in complete loss of function as clones of affected granulocytes completely negative for CD59 expression were shown in all patients. Interestingly, granulocytes in these patients contained variable proportions of affected cells varied from 50% to 100% and four of the patients had erythrocytes with diminished expression of GPI-anchored DAF and CD59 coexisting with normal and completely negative cells. Immunophenotypic analysis of reticulocytes in peripheral blood of patients with PNH demonstrated the conserved patterns of DAF and CD59 expression in circulating erythroid cells and the discrepancies between granulocytic and erythroid lineages. These findings suggested that the characteristics of abnormal phenotypes which appear to be highly variable between different hematopoietic lineages are not solely caused by mutation of PIG-A but are influenced by other factor(s).

Detection and typing of human papilloma virus DNAs in normal cervix, intraepithelial neoplasia and cervical cancer in Bangkok.

We detected and typed HPV-DNA by polymerase chain reaction (PCR) in cervico-vaginal lavages of 102 women with normal cervical cytology, 57 patients with cervical intraepithelial neoplasia (CIN), and 23 cervical cancer patients. HPV-DNA detection and typing by in situ hybridization were also performed in cervical biopsies from CIN lesions and cancers. Five percent of women with normal cervical cytology, 46% of CIN, and 61% of cervical cancer were positive for HPV-DNA. Of CIN cases with positive HPV-DNA, 69, 15, 8, 4 and 4% were HPV-16, -33, -18, -11 and -16/33 respectively. Of cervical cancer cases with positive HPV-DNA, 86% were HPV-16, 7% were HPV-16/33, 7% were HPV-18/31. HPV typing was performed in biopsies from 37 CIN and 18 cervical cancers by in situ hybridization. By this method, 38% of CIN were HPV-DNA positive, of which 71% were HPV-16 and 7% were each of HPV-11, -18, -31 and -33. Thirty-nine percent of cervical cancers were positive, of which 71% and 29% were HPV-16 and HPV-16/18 respectively.

Increased serum levels of macrophage colony-stimulating factor (M-CSF) in alpha- and beta-thalassaemia syndromes: correlation with anaemia and monocyte activation.

Serum levels of M-CSF were determined by an ELISA method in 29 and 34 patients with HbH disease (alpha 1/alpha 2 or alpha 2/HbCS) or beta zero-thal/HbE, respectively, in 28 haematologically normal subjects and in five patients with anaemia due to iron deficiency or myelodysplasia. In HbH disease and beta zero-thal/HbE, M-CSF concentrations were significantly higher than those in the normal subjects [986 +/- 138 and 1385 +/- 133, respectively, vs. 500 +/- 33 pg/ml (mean +/- SEM); p < 0.01, and p < 0.001, respectively]. By contrast, in patients with anaemia due to iron deficiency, M-CSF levels were within the normal range. In HbH disease and in beta zero-thal/HbE, M-CSF levels correlated inversely with mean basal Hb values (r = -0.39, p = 0.05 and r = -0.60, p < 0.001, respectively). In addition, in some of the HbH and beta zero-thal/HbE patients, monocyte ADCC activities towards red cells were tested and found to be approximately twice as high as those in normal controls [38.3 +/- 5.7 and 30.7 +/- 4.6 vs. 17.8 +/- 1.8% specific lysis (mean +/- SEM), respectively; p < 0.01 and p < 0.02, respectively]. When thalassaemic patients and normal controls were considered together there was a significant correlation between M-CSF levels and monocyte ADCC activities (r = 0.51, p < 0.02). The results suggest that in HbH disease and in beta zero-thal/HbE, raised serum M-CSF contributes to the anaemia by enhancing the effector function of mononuclear phagocytes towards red cells.

Activation of monocytes for the immune clearance of red cells in beta zero-thalassaemia/HbE.

We have recently provided evidence that IgG antibodies play a role in the destruction of red cells in thalassaemia syndromes. In order further to delineate factors involved in the clearance of thalassaemic cells, monocytes of 30 Thai patients with beta zero-thal/HbE (17 non-splenectomized and 13 splenectomized) and 16 normal controls were examined for their ability to bind and phagocytose normal red cells coated with IgG anti-Rh(D). In beta zero-thal/HbE, the mean number of red cells attached to the monocytes was approximately 3-fold greater than in normal controls and the number ingested 30% higher. Among the non-splenectomized patients, the number of red cells attached to and ingested by the monocytes, correlated inversely with mean basal Hb levels, suggesting that activation of mononuclear phagocytes for the immune clearance of red cells is a factor in determining the severity of the anaemia. As Fc-gamma-RI is of primary importance in the recognition of IgG-coated red cells by monocytes, leucocytes from 10 beta zero-thal/HbE patients (four non-splenectomized and six splenectomized) and five normal controls were investigated for their expression of Fc-gamma-RI by flow cytometry. In beta zero-thal/HbE there was an approximately 3-fold increase in the percentage of leucocytes expressing this receptor; the receptor was up-regulated on monocytes and induced on granulocytes. The up-regulation of Fc-gamma-RI in beta zero-thal/HbE is likely to be an important component in the activation of monocytes and in mediating their enhanced effector function towards antibody-coated cells.