Circulating cytokine levels and antibody responses to human Schistosoma haematobium: IL-5 and IL-10 levels depend upon age and infection status

Experimental schistosome infections induce strong parasite-specific Th2 responses. This study aims to relate human systemic cytokine and antibody levels to schistosome infection levels and history. Levels of anti-Schistosoma haematobium antibodies (directed against crude cercariae, egg and adult worm antigens) and plasma cytokines (IFN-γ, IL-2, IL-4, IL-5, IL-10, IL-13, IL-17, IL-21, and IL-23) were measured by ELISA in 227 Zimbabweans (6-60?years old) in a schistosome-endemic area and related to age and infection status. Egg-positive people had significantly higher levels of specific antibodies, IL-2, IFN-γ and IL-23. In contrast, egg-negative individuals had significantly higher circulating IL-10, IL-4, IL-13 and IL-21 that were detected with high frequency in all participants. Subjects with detectable plasma IL-17 produced few or no eggs. When analyzed by age, IL-4 and IL-10 increased significantly, as did schistosome-specific antibodies. However, when age was combined with infection status, IL-5 declined over time in egg-positive people, while increased with age in the egg-negative group. Older, lifelong residents had significantly higher IL-4 and IL-5 levels than younger egg-negative people. Thus, a mixed Th1/Th2 systemic environment occurs in people with patent schistosome infection, while a stronger Th2-dominated suite of cytokines is evident in egg-negative individuals.     

Serodiagnosis of Schistosoma mansoni infections in an endemic area of Burkina Faso: performance of several immunological tests with different parasite antigens

The performance of indirect haemagglutination assays (IHA), enzyme-linked immunosorbent assays (ELISA) and indirect immunofluorescent antibody tests (IFAT) were compared with 450 sera from a Schistosoma mansoni-endemic area in Burkina Faso. All participants in this survey provided at least one sample each of stool, urine and serum. From those with an egg-negative Kato-Katz thick smear, a second stool sample was examined. IHA was based on either extracts of adult S. mansoni worms (SmIHA) or S. japonicum egg antigen (SjIHA). For ELISA, three antigen preparations were used, namely: (i) soluble S. mansoni adult worm antigens (SWAP); (ii) soluble S. mansoni egg antigens (SEA); and (iii) a cationic exchange fraction of S. mansoni eggs (CEF6). IFAT was performed with S. mansoni male worm sections. Among the egg-excretors, the sensitivity of ELISA was high and egg antigens performed slightly better (SEA, 96%; CEF6, 97%) than worm antigen (94%). Sensitivity of IHA was satisfactory with homologous (Sm, >85%), but not heterologous (Sj, 56%) parasite antigen. In IFAT, the parenchyma-associated fluorescence showed high sensitivity (95%), but gut-associated fluorescence, which is known to be a sensitive diagnostic marker for schistosome-infected European travelers, was observed only in 76% of a sub-sample of 100 of the endemic sera. Among sera from egg-negative individuals, many gave positive reactions in several or all of the tests employed. These reactions (formally "false positive") are considered to represent true infections, since chemotherapy had not yet been delivered to this population. For the purpose of further surveys in Burkina Faso or other resource-poor settings, we suggest IHA as an accurate diagnostic test and propose to further improve its performance by including egg rather than worm antigens.     

日本血吸虫病流行区人群特异抗原诱导IFN-γ的应答特征

[目的 ]观察日本血吸虫病流行区人群血吸虫抗原 IFN- γ的应答特征。 [方法 ]选择江西省鄱阳湖中的南山岛上三个毗邻的自然村作为观察试区 ,根据粪检结果对 14～ 41岁人群按年龄组随机抽样 ,选取粪检结果阴性的 6 5人、粪检阳性的 6 4人为研究对象。采用全血培养法 ,检测培养上清中血吸虫抗原特异性的 IFN- γ水平 ,并检测血清中特异性抗体水平。 [结果 ]化疗后 ,人群 IFN-γ诱生水平较化疗前显著升高 ;未再感染组 SEA特异的 IFN-γ水平显著高于再感染组 ;SEA特异的 IFN -γ水平与抗 SEA的 Ig G4抗体水平之间呈显著负相关。 [结论 ]本研究结果提示 IFN-γ水平与对再感染的抗力有关     

Use of circulating cathodic antigen (CCA) dipsticks for detection of intestinal and urinary schistosomiasis

An evaluation of a commercially available antigen capture dipstick that detects schistosome circulating cathodic antigen (CCA) in urine was conducted in representative endemic areas for intestinal and urinary schistosomiasis in Uganda and Zanzibar, respectively. Under field-based conditions, the sensitivity (SS) and specificity (SP) of the dipstick was 83 and 81% for detection of Schistosoma mansoni infections while positive predictive (PPV) and negative predictive values (NPV) were 84%. Light egg-positive infections were sometimes CCA-negative while CCA-positives included egg-negative children. A positive association between faecal egg output and intensity of CCA test band was observed. Estimating prevalence of intestinal schistosomiasis by school with dipsticks was highly correlated (r=0.95) with Kato-Katz stool examinations, typically within +/-8.5%. In Zanzibar, however, dipsticks totally failed to detect S. haematobium despite examining children with egg-patent schistosomiasis. This was also later corroborated by further surveys in Niger and Burkina Faso. Laboratory testing of dipsticks with aqueous adult worm lysates from several reference species showed correct functioning, however, dipsticks failed to detect CCA in urine from S. haematobium-infected hamsters. While CCA dipsticks are a good alternative, or complement, to stool microscopy for field diagnosis of intestinal schistosomiasis, they have no proven value for field diagnosis of urinary schistosomiasis. At approximately 2.6 US dollars per dipstick, they are presently too expensive to be cost-effective for wide scale use in disease mapping surveys unless Lot Quality Assurance Sampling (LQAS) strategies are developed.     

A comparison of humoral responses to Schistosoma haematobium in areas with low and high levels of infection

Antibody responses to Schistosoma haematobium of 280 Zimbabweans were studied in two areas of differing infection levels. 133 of the subjects came from a low infection area with a prevalence of 33.8% and geometric mean infection intensity of 0.8 eggs per 10 ml of urine, while 147 of the subjects came from a high infection area with a prevalence of 62.7% and geometric mean intensity of 3.2 eggs per 10 ml of urine. Both the age-prevalence and age-intensity curves exhibited a peak shift. IgA, IgE, IgG, IgG1, IgG2, IgG3, IgG4, and IgM antibody levels against soluble egg antigen (SEA) and whole worm homogenate (WWH) were assayed by ELISA. Females produced significantly more anti-SEA IgG1, IgG4, IgM, anti-WWH IgE and IgG1. People from the high infection area produced significantly more anti-SEA IgE, IgG3 and anti-WWH IgG3 and significantly lower levels of anti-SEA IgA, IgM and anti-WWH IgM when the effects of infection intensity, sex and age had been allowed for. The age profiles of anti-SEA IgA, IgG and anti-WWH IgA and IgM reflected current levels of infection while anti-WWH IgG1, IgG2 and anti-SEA IgG1 evolved more slowly with age, and anti-WWH IgE rose with age in both areas. Some antibody responses, anti-SEA/WWH IgM, anti-SEA IgG1 and possibly anti-SEA/WWH IgA showed different age profiles in the two areas, with changes in antibody levels occurring at a younger age in the high infection area suggesting that immune responses are evolving more rapidly in residents of this area. This result clearly demonstrates that antibody levels are not a function of age alone.     

Genetic control of immunity to Heligmosomoides polygyrus: fixed H-2 E positive but not H-2 negative cells can present antigen to a parasite-specific T cell hybridoma

A number of T cell hybridomas were produced to adult worm homogenate (AWH) antigen of the nematode parasite Heligmosomoides polygyrus. All of the hybridomas were of the H-2^d haplotype and could potentially accept antigen in the context of either the A^d or E^d, H-2 molecules. Three types of antigen presentation were observed, with some of the T cell hybridomas accepting antigen in the context of the E and some in the context of the A molecule. A third type of hybridoma responded to antigen presented by paraformaldehyde fixed APC, but only when APCs were Epositive. These same hybridomas, were however, stimulated by A WH, when the antigen was presented by syngeneic but unfixed, E positive or E negative A PC. Therefore these data indicate that certain H. polygyrus-specfic T cell hybridomas can accept parasite antigen when presented in the context of either the H-2 A or E molecule, but the presentation of antigen by the two different MHC Class II molecules, can apparently utilize differing processing mechanisms.,     

In vitro stimulation of naive mouse lymphocytes by Heligmosomoides polygyrus adult worm antigens induces the production of IgG1

The production of high levels of IgG1, by mice chronically infected with the parasitic nematode Heligmosomoides polygyrus , has been documented for a number of years. In order to investigate this phenomenon, naive lymphocytes from B10.D2 mice were incubated in vitro with H. polygyrus adult worm homogenate (AWH) and the culture supernatants examined for immunoglobulin production. Stimulation of pooled naive splenocytes by AWH was found to produce IgG1, but not IgM, in an antigen dose dependent manner. Identical stimulation of splenocytes of individual inbred mice, indicated that this effect was reproducible but with considerable variation between mice. When the IgG1 produced was tested for specificity, it was found that there was little evidence that the immunoglobulin produced was able to bind to the inducing parasite antigens. Analysis of purified T cells reconstituted with splenocytes, demonstrated that T cells were the target lymphocytes of the stimulating molecule, contained within AWH. These results show that H. polygyrus AWH can induce the production of non-parasite specific IgG1 from naive splenocytes and that this production is crucially dependent upon the cell content of the in vitro culture. Furthermore, the production of IgG1 is not proportional to the degree of lymphocyte proliferation. It is suggested that at least part of the hypergammaglobulinaemia produced during a primary H. polygyrus infection, is due to this non-specific stimulation of mouse lymphocytes by the parasite.     

Association of HLA Class-II Genes and Anti-Neutrophil Cytoplasmic Antibodies in Chinese Patients with Inflammatory Bowel Disease

Background: In a preliminary study we showed that antibodies to the endoplasmic reticulum protein calreticulin (CR) occur in primary biliary cirrhosis (PBC) and autoimmune hepatitis type 1 (AIH). Since anti-CR antibodies have also been found in patients with infectious diseases, we investigated their prevalence and immunoglobulin classes in patients with various hepatic and intestinal diseases, hoping to get some information on a possible relationship between an infectious trigger and the induction of a certain class of anti-CR antibodies. Methods: Sera were tested for anti-CR antibodies of the IgA, IgG, and IgM class by Western blotting, using CR isolated from human liver: in autoimmune liver diseases (primary biliary cirrhosis (PBC) (n = 86) and autoimmune hepatitis (AIH) type 1 (n = 57)), alcoholic liver cirrhosis (ALC) (n = 32), viral liver infections (acute hepatitis A (n = 8), acute hepatitis B (n = 20), and chronic hepatitis C (n = 28)), and intestinal diseases (Crohn disease (CD) (n = 30), acute yersiniosis (n = 26)). Sera from 100 healthy individuals served as negative controls. Results: The most prominent finding was the high prevalence of anti-CR antibodies of the IgA class and the similarity in the anti-CR antibody class pattern in PBC (IgA, 62%; IgG, 43%; IgM, 55%) and yersiniosis (IgA, 62%; IgG, 39%; IgM, 42%). Class IgA anti-CR antibodies also occurred frequently in ALC (IgA, 44%; IgG, 41%; IgM, 19%). In contrast, in AIH anti-CR antibodies were predominantly of class IgG (IgA, 28%; IgG, 60%; IgM, 33%). In hepatitis A anti-CR antibodies were absent. In the other diseases they had a low prevalence and were mostly of class IgG (acute hepatitis B: IgA, 0%; IgG, 15%; IgM, 0%; chronic hepatitis C: IgA, 7%; IgG, 21%; IgM, 0%; CD: IgA, 13%; IgG, 20%; IgM, 13%). Of the healthy individuals 7% had anti-CR antibodies exclusively of class IgG. Conclusions: The high prevalence of anti-CR antibodies of class IgA in patients with PBC and yersiniosis as well as in alcoholic liver disease reflects a reactivity of the gut-associated immune system and could imply that a still undefined gut-derived bacterial (?) agent may trigger PBC.     

日本血吸虫病流行区人群吡喹酮治疗前后细胞因子水平的研究

观察日本血吸虫病流行区人群的细胞免疫应答状态及吡喹酮治疗对其影响。 [方法 ]采集日本血吸虫病流行区 12 9人 (粪检阳性者 6 4例 ,粪检阴性者 6 5例 ) ,吡喹酮治疗前及治疗后 45d的静脉血 ,以血吸虫成虫和虫卵抗原分别刺激诱生细胞因子 ,检测培养上清中的细胞因子IL 5、IL 10和IFN γ水平。 [结果 ]12 9例中 ,对血吸虫抗原刺激诱生的细胞因子水平粪检阴性组明显高于粪检阳性组 ;治疗后 ,细胞因子诱生水平较治疗前显著升高 ,特别是IL 5和IFN γ。 [结论 ]流行区人群的细胞免疫应答显示总体下调趋势 ;吡喹酮治疗后出现细胞因子水平的明显升高。     

Diagnosis of Opisthorchis viverrini Infection with Handheld Microscopy in Lao People's Democratic Republic

Opisthorchiasis is a neglected tropical disease, yet it is of considerable public health importance in Southeast Asia given the predilection for chronically infected persons to develop cholangiocarcinoma. We evaluated a handheld microscope for the diagnosis of Opisthorchis viverrini in a community-based setting in Lao People''s Democratic Republic in comparison with conventional light microscopy. In stool samples collected from 104 individuals, handheld microscopy revealed a sensitivity of 70.6% and a specificity of 89.5% for O. viverrini infection. Pearson''s correlation for quantitative fecal egg counts between the two devices was 0.98 (95% confidence interval: 0.98–0.99). With small adjustments to further increase diagnostic sensitivity, a handheld microscope may become a helpful tool to screen for O. viverrini and other helminth infections in public health settings.     

High Intraluminal Fluid Flow Increases Intestinal IgA Output

Background: Stool IgA output in normal stool or chronic diarrhoea is a fraction of that recorded in high-output watery diarrhoea due to cholera. We hypothesized that high intestinal fluid flow leads to increased IgA output, and this is not a consequence of reduced degradation/reabsorption. Methods: Daily intestinal outputs of IgA and other secretory and non-secretory proteins were measured in stool from 14 volunteers with ileostomies and compared with the output during whole-gut lavage, a whole-gut perfusion system. Results: Output into whole-gut lavage was significantly higher for all the proteins (P = 0.02 to 0.001). Median IgA output into ileostomy effluent (IE) was 3.6 mg/kg/day compared with 26 mg/kg/day into whole-gut lavage fluid (WGLF). Thus IgA recovery in stool was only 12.7% of the amount in corresponding WGLF. Similar results were found for other proteins: specific IgA and IgM antibodies (5.4%-20.3 %), IgM (42.4%), IgG (8.9%), and albumin (9.3%). Six subjects with IE water content >92% had increased recovery of IgA compared with eight with <92% water. In vitro, experiments predict that degradation of IgA within the small bowel results in 80% remaining compared with the 12.7% measured in vivo. Conclusions: Our data show that high intraluminal fluid flow increases the intestinal output of IgA and other proteins, and this is not a consequence of reduced degradation/reabsorption in the colon or small bowel. This increased protein output may be a non-specific response in the early stages of acute diarrhoea.     

Immunoglobulin M antibodies are not specific for serodiagnosis of human toxocariasis

Serodiagnosis of human toxocariasis is established by detecting serum anti‐Toxocara IgG antibodies, but there is little knowledge regarding the reactivity of human IgM antibodies against the Toxocara antigens. In this study, we have evaluated the reactivity of IgM antibodies in sera from patients with toxocariasis, patients with other helminth infections, and healthy individuals, against Toxocara larval excretory‐secretory (TES) antigens by enzyme‐linked immunosorbent assay (ELISA) and Western blot (WB). Anti‐Toxocara IgM were detected in 91.4% of sera from patients with toxocariasis, 76% of sera from patients with other helminth infections, and 45.3% of sera from healthy individuals when ELISA was used. Likewise, IgM antibodies were detected in 94.8% of sera from patients with toxocariasis, 65.3% of sera from patients with other helminth infections, and 41% of sera from healthy individuals when WB was used. This reactivity exhibited only a slight decrease when the TES antigens were deglycosylated, showing that not only glycosidic epitopes, but also peptide epitopes are involved in the recognition and binding of IgM antibodies during the immune response against the parasite. The results shown that IgM antibodies are not specific for serodiagnosis of human toxocariasis.     

Effects of Maternal Ethanol Consumption on the Subsequent Development of Immunity to Trichinella spiralis in Rat Neonates

The immune response of rat pups to the intestinal parasite Trichinella spiralis was studied to determine if maternal pre-and/or postnatal ethanol consumption affected neonatal immune responses. Female rats were fed ethanol-containing (36% of calories) or pair-fed control liquid diets and include groups that were maintained on ethanol as follows: group 1, from day 1 of pregnancy through weaning and whose pups were then placed on ethanol to sacrifice; group 2, from day 1 of pregnancy through lactation; group 3, from day 1 of pregnancy through pup delivery; and group 4, from day 1 of lactation through weaning. A parallel group of animals was pair-fed isocaloric control diet until sacrifice. The pups of all litters were immunized orally with 500 L₁ (T. spiralis) larva 5 days after weaning. To examine the effects of maternal ethanol on primary immune responses, one-fourth of the pups from each litter were sacrificed on days 10 and 20 after immunization. To examine the effects on neonatal secondary immune responses, the remaining pups were challenged with 1,000 larva 30 days after the initial immunization and sacrificed either 3 or 8 days after challenge. At the time of sacrifice, blood samples were collected, the intestine removed to determine T. spiralis worm burdens, and suspensions of mesenteric lymph node (MLN) cells prepared. Intestinal worm counts and serum levels of anti-T. spiralis IgM and IgG antibodies, interleukin-2 (IL-2), and tumor necrosis factor (TNF) were determined. In vitro proliferation responses of MLN cells to T. spiralis antigen and to the mitogen concanavalin A (Con A) were also examined. Pups from groups 1 to 3 demonstrated significantly higher intestinal worm counts (decreased immunity) than the pair-fed controls at the day 20 primary immune response sacrifice, and pups from group 1 had significantly higher worm counts at day 3 after a secondary immune challenge. Pups of dams from groups 1, 3, and 4 had significantly lower IgM antibody titers at the day 20 primary immune response sacrifice. All experimental ethanol groups (1 to 4) demonstrated significantly lower IgG antibody titers than that observed in pair-fed control pups at the 20-day sacrifice. IgM antibody titers showed significant reductions for ethanol-treated groups at 3 and 8 days after T. spiralis secondary challenge. In addition, IgG antibody titers were also significantly reduced for all alcohol groups at 3 and 8 days during the secondary immune response. Serum IL-2 and TNF levels were significantly lower in all experimental ethanol groups (1 to 4) relative to pair-fed controls at day 20 during a primary immune response, and IL-2 levels at 3 days postchallenge were lower in groups 2 to 4 after a secondary immune challenge. MLN proliferation responses to antigen and Con A were significantly reduced in ethanol groups 1 to 3 and to Con A in group 4 at day 10 after a primary immune challenge. Ethanol group 3 pups also demonstrated a reduced response to antigen at day 20. For animals undergoing a secondary immune response, ethanol group 2 demonstrated a reduced response to antigen at day 3, whereas groups 2 and 4 showed increased reactivity to antigen at days 3 and 8 postchallenge. These results show that maternal ethanol consumption diminishes the capacity of neonates to respond to T. spiralis antigen and that the depressed immune response involves T-and B-cell–mediated reactions and also affects the production of certain cytokines. These results also suggest that the diminished immune responses are increased with longer periods of maternal and neonatal exposure to ethanol.     

Opisthorchis viverrini: Evaluation of 28 kDa glutathione S-transferase as diagnostic tool in human opisthorchiasis

The liver fluke Opisthorchis viverrini is the agent of human opisthorchiasis in Thailand with a high prevalence observed in the rural population of north and northeastern regions of the country. A focus of research has therefore been the development of diagnostic tools to indicate infection by this parasite. In the present study, a 28 kDa glutathione S-transferase of O. viverrini (OV28GST), which is found in the excretion/secretion product of the parasite, was evaluated for its application in diagnosis of human opisthorchiasis. Bacterially expressed and functionally active rOV28GST was used in immunoblots and indirect ELISA to detect anti-OV28GST antibody in sera of infected individuals. Crude whole worm extract, sera of uninfected individuals and a rabbit anti-rOV28GST antiserum were used as controls in the assays while positivity for parasite DNA by PCR and egg count in faeces were used as primary indicators of infection. The results showed weak or absent reactivity of the infected sera to immunoblotted rOV28GST and no significant difference in absorbance values when compared to uninfected sera in ELISA. In addition, a glutathione capture ELISA which was performed to test for circulating OV28GST in human and hamster sera showed negative results. In conclusion, OV28GST is not applicable as a diagnostic tool in established infections due to low specific antibody titre and abundance as circulating antigen.     

Antibody Reactivity of a Standardized Human Serum Protein Solution Against a Spectrum of Microbial Pathogens and Toxins: Comparison with Fresh Frozen Plasma

Abstract: In this study, we compared a standardized solution of human serum protein (HSP) and fresh frozen plasma (FFP) with regard to the antibody specificity against a number of microbial pathogens and some important pathogenicity factors of bacterial pathogens. Due to the clinical use of HSP and FFP for therapeutical plasma exchange, we have chosen a spectrum of microbial pathogens for serological analysis that is critical in clinical settings. With the enzyme‐linked immunosorbent assay technique, we could show that HSP contains marked IgG antibody reactivity against antigens of Escherichia coli, Campylobacter jejuni, Enterobacter sakazakii, Proteus mirabilis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, S. epidermidis, Streptococcus pneumoniae, Enterococcus faecalis, Chlamydia pneumoniae, and Candida albicans. Although no IgM antibodies against the pathogens tested could be detected in HSP, moderate IgA reactivity was found against 4 of 12 microbial antigens. Immunoblot analysis demonstrated specific IgA and IgG responses against the endoproteinase Glu‐C and the superantigens enterotoxin A and B of S. aureus, the IgA‐protease of Neisseria gonorrhoeae, and Shiga toxin 2 of enterohemorrhagic E. coli. By using 3 different HSP batches in parallel, we could demonstrate antibody reactivity against important microbial pathogens and toxins. This antibody profile is essentially more homogeneous than that of 3 batches of FFP.     

Clinical manifestations and antiphosphatidylserine antibodies in patients with systemic lupus erythematosus: is there an association?

Objective: Antiphospholipid antibodies are a group of heterogeneous autoantibodies which have been reported in systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS) in association with thrombosis, fetal loss, and thrombocytopenia. In this study, we aimed to reveal the prevalence and correlation of IgG, IgA, and IgM isotypes of antibodies to cardiolipin (aCL) and antiphosphatidylserine (aPS) with clinical and laboratory manifestations of SLE patients. Methods: Fifty-nine SLE patients and 41 healthy controls were included. Fifteen of patients (25.4%) had secondary APS. aCL and aPS antibody assays were performed by enzyme-linked immunosorbent assay. Results: All isotypes of aCL and aPS antibodies except IgG were higher in patients with or without APS than those in the healthy controls (p<0.001). The most significant associations were found among migraine and IgA aCL (p<0.001), livedo reticularis and both IgM aCL and IgM aPS (p<0.001), migraine and IgM aCL (p<0.01), pulmonary involvement and IgM aCL (p<0.01), migraine and IgA aPS (p<0.01), and both thrombosis and migraine with IgM aPS (p<0.01). Conclusion: A relatively high prevalence of aCL and aPS antibodies was found in our SLE patients. It seems that isotypes of IgM aCL, IgM aPS, IgA aCL, and IgA aPS antibodies are correlated well with migraine and IgM aPS with thrombosis in SLE patients with secondary APS. The assessment of both IgM and IgA isotypes of aPS and aCL antibodies may be helpful in predicting these manifestations.     

Schistosomiasis mansoni: immunoblot analysis to diagnose and differentiate recent and chronic infection.

One hundred seven patients classified into three different groups (11 with acute schistosomiasis, 58 with chronic schistosomiasis, and 38 children with high IgM-specific antibody titers against schistosome gut-associated antigens living in an endemic schistosomiasis area) were studied by immunoblotting for the presence of IgG, IgM, and IgA antibodies against Schistosoma mansoni soluble adult worm antigen preparation. We used sera from 15 individuals infected with various intestinal parasites, as well as sera from 19 uninfected individuals, as controls. An immunogenic fraction with a molecular weight of 31-32 kD (Sm31/32) was the most frequently recognized by the different antibody isotypes. In the group with acute disease, this fraction was recognized by IgG and IgM antibodies of all patients, and by 10 (90.9%) of 11 samples for IgA antibodies. Approximately 98% of the patients with chronic infections had IgG antibodies against Sm31/32, but only about 10% had IgM and IgA antibodies against this fraction. The IgG immunoblot profiles of the children from the endemic area were similar to those obtained for the group with acute schistosomiasis. This observation suggests recent infection of these children. Our data show that the Sm31/32 protein fraction is highly immunogenic and may be a useful serologic marker for diagnosing and differentiating between acute and chronic schistosomiasis infection.     

High titres of IgA antibodies to enterovirus in fulminant type-1 diabetes

Aims/hypothesis We have recently proposed that fulminant type-1 diabetes is a novel subtype of type-1 diabetes with abrupt onset of insulin-deficient hyperglycaemia without islet-related autoantibodies. The pathogenesis is still unknown, but flu-like symptoms are frequently observed before the onset of disease of this subtype. Enterovirus infection is a candidate environmental factor causing type-1 diabetes. The aim of this study was to determine whether enterovirus infection contributes to the development of fulminant type-1 diabetes.Methods We investigated 19 patients with recent-onset fulminant type-1 diabetes, 18 patients with recent-onset typical type-1A diabetes, and 19 healthy controls. IgM, IgG, and IgA subclasses of antibodies to enterovirus were determined by ELISA.Results IgA antibody titres to enterovirus were significantly higher in fulminant type-1 diabetes than in typical type-1A diabetes (p=0.033) and controls (p=0.0003). IgM antibodies to enterovirus were not detected in any subject. IgG titres were lower in autoimmune diabetes than fulminant type and controls (p=0.014 and 0.019, respectively).Conclusions/interpretation High titres of enterovirus IgA antibodies in serum suggest recurrent enterovirus infection in fulminant type-1 diabetic patients, indicating higher susceptibility to enteroviral infections among them. Such infections might have pathogenetic importance in the triggering of fulminant type-1 diabetes.     

Serum immunoglobulin G, M and A response to Cryptosporidium parvum in Cryptosporidium-HIV co-infected patients

Background  

Cryptosporidium parvum, the protozoan parasite, causes a significant enteric disease in immunocompromised hosts such as HIV patients. The present study was aimed to compare serum IgG, IgM and IgA responses to crude soluble antigen of C. parvum in HIV seropositive and seronegative patients co-infected with Cryptosporidium and to correlate the responses with symptomatology.