Latha Jagannathan

HLA-B∗57 and Gender Influence the Occurrence of Tuberculosis in HIV Infected People of South India

Background. Substantial evidence exists for HLA and other host genetic factors being determinants of susceptibility or resistance to infectious diseases. However, very little information is available on the role of host genetic factors in HIV-TB coinfection. Hence, a longitudinal study was undertaken to investigate HLA associations in a cohort of HIV seropositive individuals with and without TB in Bangalore, South India. Methods. A cohort of 238 HIV seropositive subjects were typed for HLA-A, B, and DR by PCR-SSP and followed up for 5 years or till manifestation of Tuberculosis. HLA data of 682 HIV Negative healthy renal donors was used as control. Results. The ratio of males and females in HIV cohort was comparable (50.4% and 49.6%). But the incidence of TB was markedly lower in females (12.6%,) than males (25.6%). Further, HLA-B*57 frequency in HIV cohort was significantly higher among females without TB (21.6%, 19/88) than males (1.7%, 1/59); P = 0.0046; OR = 38. CD4 counts also were higher among females in this cohort. Conclusion. This study suggests that HIV positive women with HLA-B*57 have less occurrence of TB as compared to males.

Risk factors for chronic hepatitis B virus infection among blood donors in Bangalore, India.

Objectives and Aim: We performed a study of hepatitis B virus (HBV) risk factors among blood donors in Bangalore, India.

Comparative Analyses of Low, Medium and High-Resolution HLA Typing Technologies for Human Populations

Human Leukocyte Antigen (HLA) encoding genes are part of the major histocompatibility complex (MHC) on human chromosome 6. This region is one of the most polymorphic regions in the human genome. Prior knowledge of HLA allelic polymorphisms is clinically important for matching donor and recipient during organ/tissue transplantation. HLA allelic information is also useful in predicting immune responses to various infectious diseases, genetic disorders and autoimmune conditions. India harbors over a billion people and its population is untapped for HLA allelic diversity. In this study, we explored and compared three HLA typing methods for South Indian population, using Sequence-Specific Primers (SSP), NGS (Roche/454) and single- molecule sequencing (PacBio RS II) platforms. Over 1020 DNA samples were typed at low resolution using SSP method to determine the major HLA alleles within the South Indian population. These studies were followed up with medium resolution HLA typing of 80 samples based on exonic sequences on the Roche/454 sequencing system and high-resolution (6-8 digit) typing of 8 samples for HLA alleles of class I genes (HLA-A, B and C) and class II genes (HLA-DRB1 and DQB1) using PacBio RS II platform. The long reads delivered by SMRT technology, covered the full-length class I and class II genes/alleles in contiguous reads including untranslated regions, exons and introns, which provided phased SNP information. We have identified three novel alleles from PacBio data that were verified by Roche 454 sequencing. This is the first case study of HLA typing using second and third generation NGS technologies for an Indian population. The PacBio platform is a promising platform for large-scale HLA typing for establishing an HLA database for the untapped ethnic populations of India.

Red Blood Cell Alloimmunization in Multi - transfused Patients: A Bicentric Study in India

Background: It is well-known that alloimmunization to red blood cell antigens resulting from the genetic disparities between donor and recipient is one of the risks of blood transfusion. The antibody screening cells are used to detect unexpected antibodies. The risk of alloimmunization is higher in patients who have received multiple blood transfusions such as thalassemia, other hematological disorders, renal failure patients on dialysis who receive blood transfusions, and females with bad obstetric history. Antibody screening test using 2–3 cells panel is not a mandatory pretransfusion testing in India and is performed routinely in limited blood centers. Materials and Methods: This bicentric study has been carried out to look at prevalence of antibodies in multi-transfused patients who have higher risks of alloimmunization such as patients who have received multiple blood transfusions such as thalassemia, other hematological disorders, renal failure patients on dialysis who receive blood transfusions, and females with bad obstetric history in the North as well as South India. The study was conducted at two blood centers, one regional blood transfusion of North India and one at South India. Totally, 4569 cases were analyzed and 258 patients were selected for antibody screening and identification. Results: Of total 4569 patients, 258 multi-transfused patients were studied. Among these, seven patients (2.71%) were found alloimmunized. The risk of alloimmunization was 2.90% in thalassemia, 0% in chronic renal failure patients, 3.77% in pregnant females with bad obstetric history, and 2.78% in other multi-transfused patients like cancer. Discussion: Regular monitoring through antibody screening and transfusion of blood matched for minor erythrocyte antigens are recommended in these patients.

An unusual case of a potentially clinically significant anti-M antibody in a healthy male blood donor without any history of blood transfusion

Dear Sir, The prevalence of red blood cell (RBC) alloantibodies among general, hospital-based patients typically has averaged approximately 1% in various studies. The presence of irregular antibodies in healthy voluntary blood donors is uncommon. Anti-M is a fairly common, naturally occurring antibody. Most anti-M are not active at 37 oC and generally are ignored in transfusion practice1. Sometimes, however, they can be clinically significant and become a problem in the immunohaematology laboratory. A male volunteer donor age 32 years donated blood in August 2008. Blood cell grouping showed an “A” positive phenotype, but serum grouping showed a positive reaction (+3) with all the three reagent red cells: A cells, B cells and O cells. The tests were repeated on the ID-Card, DiaClon ABO/D + reverse grouping (gel card) and the same results were observed. When reverse grouping tubes were tested at three different temperatures, 4 oC, 22 oC and 37 oC, for 1 hour, the reaction remained the same at 22 oC and 37 oC but negative at 4 oC. Autocontrols and the direct antiglobuling test were negative. With an antibody screening cell panel, two out of three cells showed positive results and an antibody identification panel (ID-DiaPanel 1-11 by DiaMed, Gmbh 1785 cressier, FR, Switzerland) showed that the suspected antibody was anti-M. The most likely type of antibody was IgG as the plasma was reactive even after treatment with dithiothreitol, which destroys IgM antibodies2. The A1 and O cells used for reverse grouping were shown to be positive for the M antigen. The anti-M present in the sample was interfering in reverse grouping with A1 and O cells. The A1 and O cells treated with papain enzyme gave a negative reaction in reverse grouping, as papain destroys the M antigen. This further confirmed the presence of anti-M with a wide thermal range, reacting at room temperature as well as at 37 oC. The antibody should, therefore, be considered potentially clinically significant. In blood donors, the prevalence of naturally occurring anti-M detectable in microplates with saline suspended cells at room temperature is one in 2,500 with M+N– cells and one in 5,000 with M+N+ cells 3. Some anti-M antibodies are pH-dependent and react at the optimum pH of 6.5. Another feature of this antibody is its failure to react with ficin- or papain-premodified cells. Proteolytic enzymes, such as ficin and papain, cleave the red cell membrane at well-defined sites. Haemolytic disease of newborn, of varying degrees of severity, has been reported in association with anti-M4,5.

A study of centralized individual donor nucleic acid testing for transfusion transmitted infections to improve blood safety in Karnataka, India

Introduction: Karnataka state has a total of 176 blood banks, with a total collection of around 650,000 units annually. From January 2014, all units under the Department of Health and Family Welfare services are tested at NAT Lab established at the Central facility and from September 2014, standalone Regional Blood Transfusion Centre was included in the State Government project. Aim and Objective: The aim of the study is to analyze the nucleic acid testing (NAT) for our donor population and demonstrate consolidation of blood transfusion service through a centralized testing center for NAT and also to assess safety benefits of implementing individual donor NAT (IDNAT). Materials and Methods: We collect nearly 40,000 units annually from voluntary donors with 30% repeat donations. The donors undergo strict predonation counseling, donor questionnaire, and medical examination. The units collected are tested for human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV) by ECI using VItros 3600. All the units are tested by NAT at Central NAT Lab, screened by Procleix® Panther System by Grifols. Results: From September 2014 to March 2016, total 50,903 samples tested for NAT. Of 50,903 samples, 588 samples (1.15%) were reactive by Chemiluminescence including 265 for HBV, 188 for HCV, and 135 for HIV. Total NAT reactive samples were 254, out of this 11 reactive for HIV-1 (0.02%), 2 reactive for HCV (0.003%), 235 (0.46%) reactive for HBV. There was one HIV and 10 HBV infection cases that were not detected by serology but reactive by NAT. The yield detected is 0.021% or one in 5000. Conclusion: The IDNAT project has helped in preventing window period infections thus reducing the treatment cost and burden on healthcare. It has added benefits in blood safety and should be considered along with the basic quality assured blood transfusion system such as volunteer base for blood donation, provision of donor self-deferral, donor notification, and quality assured sensitive serological methods.