BackgroundViral hepatitis is a serious global public health problem affecting billions of people globally, and both hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are rapidly spreading in the developing countries including Bangladesh due to the lack of health education, poverty, illiteracy and lack of hepatitis B vaccination. Also there is lack of information on their prevalence among the general population. So, a population-based serological survey was conducted in Dhaka to determine the prevalence and risk factors of HBV and HCV infections.MethodsHealthy individuals were selected for demographic and behavioural characteristics by stratified cluster sampling and blood tested for hepatitis B surface antigen (HBsAg), antibody to HBV core antigen (anti-HBc), and anti-HCV antibodies (anti-HCV).ResultsFrom June 2005-November 2006, 1997 participants were screened for HBsAg, anti-HBc and anti-HCV, 738 (37%) were males with mean (SD) age of 24 (14) years. HBV-seropositivity was documented in 582 (29%) participants: 14 (0.7%) were positive for HBsAg, 452 (22.6%) for anti-HBc and 116 (5.8%) for both HBsAg and anti-HBc. Four (0.2%) participants were positive for anti-HCV, and another five (0.3%) for both anti-HBc and anti-HCV. Ninety-six/246 (39%) family members residing at same households with HBsAg positive participants were also HBV-seropositive [74 (30.1%) for anti-HBc and 22 (8.9%) for both HBsAg and anti-HBc], which was significantly higher among family members (39%) than that of study participants (29%) (OR 1.56; p < 0.001). In bivariate analysis, HBV-seropositivity was significantly associated with married status (OR 2.27; p < 0.001), history of jaundice (OR 1.35; p = 0.009), surgical operations (OR 1.26; p = 0.04), needle-stick injuries (OR 2.09; p = 0.002), visiting unregistered health-care providers (OR 1.40; p = 0.008), receiving treatment for sexually transmitted diseases (STD) (OR 1.79; p = 0.001), animal bites (OR 1.73; p < 0.001); ear-nose-body piercing in females (OR 4.97; p < 0.001); circumcision (OR 3.21; p < 0.001), and visiting community barber for shaving in males (OR 3.77; p < 0.001). In logistic regression analysis, married status (OR 1.32; p = 0.04), surgical operations (OR 1.39; p = 0.02), animal bites (OR 1.43; p = 0.02), visiting unregistered health-care providers (OR 1.40; p = 0.01); and ear-nose-body piercing in females (OR 4.97; p < 0.001) were significantly associated with HBV-seropositivity.ConclusionsThe results indicate intermediate level of endemicity of HBV infection in Dhaka community, with much higher prevalence among family members of HBsAg positive individuals but low prevalence of HCV infections, clearly indicating need for universal hepatitis B vaccination. The use of disposable needles for ear-nose-body piercing need to be promoted through public awareness programmes as a preventive strategy.

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A human neoplastic B cell line SSK41 that expresses IgM on its surface switches spontaneously to IgG-producing cells. The SSK41 line contains a single immunoglobulin heavy-chain locus, the constant region (C) genes of which retain the germline configuration. The IgG-producing SSK41 line was purified by sorting, and shown to have undergone S-S recombination with deletion of the C mu gene. This line produced secretory and membrane-bound forms of gamma-chain mRNA. From cDNA libraries of a mixed population of IgM+/IgG+ SSK41 cells, we have isolated cDNA clones encoding the mature membrane-bound and secretory forms of the mu and gamma 1 heavy chains, all of which share the same variable region sequence. cDNA clones containing the mature gamma 3 chain were identified as well. We also isolated cDNA clones containing C gamma 1 and C gamma 3 sterile transcripts from the SSK41 line. These sterile transcripts contained additional exon sequences designated 'I' which were localized upstream of the C gamma 1 and C gamma 3 switch regions and homologous to murine counterparts. The I sequences were precisely spliced to the 5' ends of the corresponding C gamma exon sequences. These features of germline CH transcripts, i.e. the isotype specificity to class switching, location of exons, and sequences per se, are highly conserved between man and mouse.

Routine antenatal hepatitis B surface antigen (HBsAg) screening and immunization of risk babies is very effective in preventing perinatal transmission of hepatitis B virus (HBV). We studied 1,800 parturients attending a public hospital to assess the rationale for such vaccination in Bangladesh. In one in every 29 deliveries (63 of 1,800 or 3.5%), the mother was found to be HBsAg positive. All were asymptomatic and many (41 of 63 or 65%) without risk factors would remain undetected if HBsAg screening were performed on selected groups. Most of the HBsAgpositive mothers (54 of 63 or 85.7%) were found to be chronic carriers and 30.2% (19 of 63) were also hepatitis B e antigen (HBeAg) positive, indicating high infectivity. Although 23 cord blood were positive for HBsAg or HBeAg, none were positive for IgM antibody to hepatitis B core antigen (IgM anti-HBc), suggesting transplacental transmission of the antigens rather than intrauterine infection. These findings are discussed in relation to the cost-effectiveness of routine prenatal screening and immunization of risk babies compared with universal infant immunization.

The pharmacokinetics of recombinant human granulocyte-macrophage colony- stimulating factor (rhGM-CSF), induction of anti-GM-CSF antibodies, and clinical effects related to the induction of the antibodies were analyzed in patients with metastatic colorectal carcinoma (CRC) who were not on chemotherapy (n = 20, nonimmunocompromised patients). rhGM- CSF (250 micrograms/m2/d; Escherichia coli-derived) was administered subcutaneously for 10 days every month for 4 months. Eight patients with multiple myeloma (MM) on intensive chemotherapy followed by rhGM- CSF treatment were also included (immunocompromised patients). After a single injection of GM-CSF at the first cycle in CRC patients, the maximum calculated concentration (Cmax) was 5.24 +/- 0.56 ng/mL; the half life (T1/2) was 2.91 +/- 0.8 hours; and the area under the concentration curve (AUC) was 30.86 +/- 6.03 hours x ng/mL (mean +/- SE). No anti-GM-CSF antibodies were detected. During the subsequent cycles, 95% of the CRC patients developed anti-GM-CSF IgG antibodies, which significantly altered the pharmacokinetics of rhGM-CSF at the third and fourth cycles with decreased Cmax (2.87 +/- 0.57 ng/mL; P < .05), T1/2 (1.57 +/- 0.2 hours; P < .05), and AUC (14.90 +/- 4.10 hours x ng/mL; P < .005). The presence of anti-GM-CSF antibodies significantly reduced the GM-CSF-induced enhancement of granulocytes, and there was a clear tendency for a decreased increment of monocytes. Antibodies diminished systemic side effects of rhGM-CSF. Only 1 of 8 MM patients showed a very low anti-GM-CSF antibody titer after GM-CSF therapy, as shown by enzyme-linked immunosorbent assay and Western blot. Therefore, in nonimmunocompromised patients, exogenous nonglycosylated GM-CSF induced an anti-GM-CSF IgG antibody response in practically all patients, which seemed to be of clinical significance. In immunocompromised patients, virtually no significant antibody response was shown.

Background:Little is known about infection rates for human immunodeficiency virus (HIV) and other diseases that can be transmitted sexually in Bangladeshi women who may be at intermediate levels of risk-that is, women who are not commercial sex workers (CSWs) but whose sexual contacts may include men at high risk for STD. This study examines HIV/hepatitis/STD and other genital tract infections in women living near Tejgaon truck stand in Dhaka, Bangladesh. Methods: This population based study was conducted from January to December 1998. A random sample of 384 women provided urine and blood samples and participated in an interview; 261 of them also had a physical examination in which vaginal and cervical specimens were taken. Laboratory tests included PCR on urine and cervical swabs for gonorrhoea and chlamydia, culture for trichomoniasis, serology tests for syphilis, herpes simplex 2, hepatitis B, C, D, HIV1, HIV2, and clinical diagnoses of other genital tract infections. Results: None of the participants tested positive for HIV. In the 261 women who had a physical examination, trichomoniasis was detected in 19.5%, chlamydia in 3.4%, gonorrhoea in 5.4%, bacterial vaginosis in 37.2%, and candidiasis in 10%. In the full sample of 384 women, with tests of urine and blood, prevalence of infection with chlamydia, gonorrhoea, syphilis, and herpes simplex 2 was detected in 0%, 6.3%, 5.7%, and 32% respectively. Almost 50% of the subjects had ever been exposed to hepatitis B, 3.6% were currently infective, 1.6% had hepatitis C, and none had hepatitis D. Conclusion:The high prevalence of certain of these infectious diseases indicates the need to implement prevention interventions with these women and, perhaps more importantly, with their male partners. Qualitative research is needed to provide insights into their sexual behaviour and the contexts in which high risk behaviours occur. (Sex Transm Inf 2001;77:344-350)

To analyze human IgA subclass-specific mRNA we have developed RNA probes for quantitation of alpha 1 and alpha 2 heavy chain constant region genes by solution hybridization. Under our assay conditions, we can detect as little as 3 pg of specific mRNA and there is less than 2% cross-reactivity between the two IgA subclasses. Using this method, the relative proportions of IgA1 and IgA2 mRNA in pokeweed mitogen (PWM)-stimulated cells were found to be 66% and 34%, respectively, while in the Epstein-Barr virus (EBV)-stimulated cells they were 77% and 23%, respectively. Cytoplasmic staining of the plasma cells and determination of IgA subclass distribution by flow cytometry revealed an almost even distribution of the two IgA subclasses as induced by both activators. The culture supernatant contained 72% IgA1 and 28% IgA2 after PWM stimulation, while EBV stimulation induced 85% IgA1 and 15% IgA2. This report thus describes a method for the quantitative analysis of IgA subclass-specific mRNA. Furthermore, we present evidence that in response to in vitro stimulation of peripheral blood lymphocytes by polyclonal activators the IgA-producing B cells not only synthesize both isotypes but also have the potential to secrete them.

The fractional catabolic rate of IgG in the body is regulated with precision in order to maintain appropriate serum concentrations. We have investigated the turnover rate of normal human IgG3, a newly identified, naturally occurring, truncated form of IgG3 and a human-mouse chimeric IgG3 antibody in an immunodeficient mouse strain, C.B-17 (SCID), lacking endogenous Ig. The half-life of non-truncated, normal serum IgG3 as well as the chimeric antibody was about 7 days, whereas truncated IgG3 had a shorter half-life of about 5 days. Due to the inherent immune defect, the SCID mouse could represent a versatile animal model for the determination of turnover rates, inasmuch as an immune response will not be mounted against foreign antigens.