ABSTRACT
AIM: To explore the role of killer immunoglobulin receptor (KIR) genes in responsiveness or non-responsiveness to vaccination against hepatitis B virus. METHODS: We recruited 101 voluntary participants between March 2010 and December 2011. Sera samples from vaccinated and non-vaccinated participants were tested for the presence of anti-HBs antibodies as a measure of protection against hepatitis B, hepatitis B surface antigen and hepatitis B core antibody as indicators of infection by enzyme-linked immunosorbent assay. KIR gene frequencies were determined by polymerase chain reaction. RESULTS: Sera samples from 99 participants were tested for the levels of anti-HBs as an indicator of protection (≥ 10 mIU/mL) following vaccination as defined by the World Health Organization international reference standard. Among the vaccinated participants, 47% (35/74) had anti-HBs titers above 100 mIU/mL, 22% (16/74) had anti-HBs ranging between 10-100 mIU/mL, and 20% (15/74) had values of less than 10 mIU/mL. We report the lack of significant association between the number of vaccine dosages and the titer of antibodies among our vaccinated participants. The inhibitory KIR2DL1, KIR2DL4, KIR3DL1, KIR3DL2, and KIR3DL were detected in more than 95%, whereas KIR2DL2, KIR2DL3, KIR2DL5 (KR2DL5A and KIR2DL5B) were expressed in 56%, 84% and 42% (25% and 29%) of participants, respectively. The observed frequency of the activating KIR genes ranged between 35% and 55% except for KIR2DS4, detected in 95% of the study participants (40.6% 2DS4*001/002; 82.2% 2DS4*003/007). KIR2DP1 pseudogene was detected in 99% of our participants, whereas KIR3DP*001/02/04 and KIR3DP1*003 had frequencies of 17% and 100%, respectively. No association between the frequency of KIR genes and anti-HBs antibodies was detected. When we compared the frequency of KIR genes between vaccinated individuals with protective antibodies titers and those who lost their protective antibody levels, we did not detect a significant difference. KIR2DL5B was significantly different among different groups of vaccinated participants (group I > 100 mIU/mL, group II 10-100 mIU/mL, group III < 10 mIU/mL and group IV with undetectable levels of protective antibodies). CONCLUSION: To our knowledge, this is the first study screening for the possible role of KIR genes among individuals vaccinated against hepatitis B virus (HBV). Our results can be used to design larger studies to better understand the role of KIR genes in protection against or susceptibility to HBV post vaccination.
ABSTRACT
AIM: To identify gaps in the existing knowledge on single, dual and triple infections of human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV) in the Middle East and North Africa (MENA) region among men who have sex with men (MSMs), female sex workers (FSWs), injecting drug users (IDUs) and prisoners. METHODS: We performed an extensive literature search on articles published on the topic in the 25 countries of the MENA region. PubMed database was used as the main search engine. Case reports, case series, qualitative studies, editorials, commentaries, authors' replies and animal studies were excluded. Original articles and reviews dealing with the prevalence of HIV, HBV and HCV and their co-infection were included. Data on population type, sample size, age and markers of infections were extracted from the relevant studies. RESULTS: HIV, HBV and HCV are blood-borne viruses with similar modes of transmission. The categories of people at high risk of acquiring HIV-1, HBV and HCV commonly include: MSMs, FSW and IDUs. It is well established that HIV-positive individuals co-infected with HBV or HCV suffer from liver pathology associated with morbidity and mortality. Moreover, HIV-infected individuals do not respond well to treatment for HBV or HCV and hence are at increased risk of hepatic toxicity. Consequently, co-infection of HIV-positive individuals with HBV and/or HCV is a global health problem of significant magnitude. Our review reveals the paucity of epidemiological data for key populations in many countries of the region. Limited number of studies exists in the MENA region on the status of HIV, HBV and HCV and their co-infections among prisoners, MSMs and FSWs. Evidence support the continued increase of the HIV epidemic among MSMs. In addition to the lack of studies on MSMs and FSWs in the MENA region, our review highlights the lack of data on the practices, characteristics, or the status of HIV infection and viral hepatitis among male sex workers selling or exchanging sex for money. CONCLUSION: The MENA countries are in urgent need of advanced research and strengthening of the data collection systems and reporting practices of these infections among key populations.
