Molecular genotyping of clinically important blood group antigens in patients with thalassaemia

Background & objectives: In multitransfused thalassaemic patients, haemagglutination fails to phenotype the patient's blood group antigens due to the presence of donor-derived erythrocytes. DNA-based methods can overcome the limitations of haemagglutination and can be used to determine the correct antigen profile of these patients. This will facilitate the procurement of antigen-matched blood for transfusion to multitransfused patients. Thus, the aim of this study was to compare the serological phenotyping of common and clinically important antigens of Rh, Duffy, Kell, Kidd and MNS blood group systems with molecular genotyping amongst multitransfused thalassaemic patients. Methods: Blood samples from 200 patients with thalassaemia and 100 'O' group regular blood donors were tested using standard serological techniques and polymerase chain reaction-based methods for common antigens/alleles (C, c, D, E, e, Fya, Fyb, Jka, Jkb, K, k, M, N, S, s). Results: Genotyping and phenotyping results were discordant in 77 per cent of thalassaemic patients for five pairs of antithetical antigens of Rh, Duffy, Kell and Kidd blood group systems. In the MNS blood group system, 59.1 per cent of patients showed discrepancy. The rate of alloimmunization among thalassaemics was 7.5 per cent. Interpretation & conclusions: Molecular genotyping enabled the determination of the actual antigen profile in multitransfused thalassaemia patients. This would help reduce the problem of alloimmunization in such patients and would also aid in the better management of transfusion therapy.

Immunoglobulin Levels and CD4 / CD8 Counts in β – Thalassemia Major.

Objective: This cross-sectional study determined the CD4, CD8 counts and serum immunoglobulins in transfusion dependent β - thalassemic patients, and correlated them with anti-HIV, anti-HCV and HBsAg status, number of transfusions, iron overload and splenectomy. Methods: Patients with acute or chronic diseases (except HIV, Hepatitis B and C), on immunosuppressive drugs or vaccinated within one month prior to study were excluded. CD4, CD8 counts and serum Immunoglobulins were documented. Results: Increasing transfusions led to higher IgA and IgM as well as a decline in CD4 and CD8 levels. Higher ferritin correlated with high IgM. CD4, CD8 and IgA were significantly higher in splenectomized subjects. HCV correlated significantly with lower IgA values. Conclusion: Higher transfusion requirement, iron overload, splenectomy and HCV infection correlated with alterations in different immunological parameters.

Safety and Immunogenicity of a Quadrivalent Meningococcal Conjugate Vaccine (MenACYW-DT): A Multicenter, Open-label, Non-randomized, Phase III Clinical Trial.

Objective: To assess the safety and immunogenicity of a quadrivalent meningococcal (groups A,C,Y,W) polysaccharide diphtheria toxoid conjugate vaccine (MenACYW-DT) in India. Design: Open-label, descriptive, non-randomized study. Setting: Three medical college hospitals, one each in New Delhi, Bengaluru and Mumbai, India. Participants: 300 healthy, vaccine-naïve participants (100 children aged 2-11 years, 100 adolescents aged 12-17 years, and 100 adults aged 18-55 years). Intervention: One dose (0.5 mL) of MenACYW-DT administered intramuscularly. Main outcome measures: Serum bactericidal antibody titers against A, C, Y, and W were measured before and after MenACWY-DT vaccination. Safety data were also collected Results: Thirty days post-vaccination, geometric mean titers rose across all serogroups. Most participants had protective titers ≥8 (1/dil) across the four serogroups. The percentage (95% CI) achieving ≥8 (1/dil) in the Adolescent Group was typical – A: 96.9% (91.2%; 99.4%); C: 96.9% (91.2%; 99.4%); Y:100% (96.3%; 100%); W:100% (96.3%; 100%). In general, solicited reactions were mild and short-lived. Unsolicited events were uncommon and unrelated to vaccination. Conclusions: MenACYW-DT was well tolerated and elicited a robust and protective immune response 30 days post-vaccination against meningococcal serogroups A, C, Y, and W-135 in the Indian study participants aged 2-55 years.

Isolation of Streptobacillus moniliformis from the blood of a child with acute lymphoblastic leukaemia.

This is an unusual report of isolation of Streptobacillus moniliformis from the blood of a male child with acute lymphoblastic leukaemia. No history of rat bite was there, but rats were present in the house. The possible source of infection may be food or water contaminated with rat excreta. Whether this bacteria can cause opportunistic infection in leukaemic patients, need to be evaluated further.

Acquired pure red cell aplasia in a child.

Primary acquired pure red cell aplasia is a rare occurrence in childhood. An eleven-year old boy presented to us with pallor, which required multiple packed red cell transfusions. He did not have hepatosplenomegaly, jaundice or lymphadenopathy. Bone marrow examination revealed the diagnosis of pure red cell aplasia. All possible investigations were done to exclude secondary causes of pure red cell aplasia. No secondary cause was found on investigations. Rheumatoid factor and anti-nuclear antibodies were positive. He was started on oral steroids, to which he did not respond. He was then given cyclosporine A. Response to cyclosporine was dramatic and the child now does not require any transfusions.

Clinical spectrum of HIV infection.

OBJECTIVE: To study the modes of transmission of pediatric HIV infection, to categorize clinical manifestations and to compare clinical spectrum of perinatal with transfusion acquired HIV infection. DESIGN: Case series study. SETTING: Hospital based pediatric HIV clinic. METHODS: Children confirmed to have HIV infection were evaluated and relevant details recorded. RESULTS: 55 children were enrolled of whom 41 (74.5%) had perinatal transmission of HIV, 12 (21.8%) were infected through blood transfusions and 2 (3.6%) through other routes. Thirty-seven (90.2%) of the 41 perinatally infected children were symptomatic. Tuberculosis was seen in 25 (67.5%) of these children and failure to thrive in 18 (48.6%). Nonspecific features such as recurrent bacterial infection, oral candidiasis and chronic diarrhea were other manifestations. Eight (26.3%) of the 30 children available for follow up for a median period of 9 months died at the median age of 8.5 months. Amongst the transfusion acquired HIV infection, 11 (91.6%) of the 12 were asymptomatic at presentation. Six (50%) of these children died at the median age of 3 years and the remaining 6 had no major symptoms at a median follow up of 3.5 years. CONCLUSION: Perinatal route is the major route of HIV transmission in children and clinical manifestations are different from those of adults.

Anemia in newborn.

Various blood indices vary in a newborn as compared to older child or adult. It depends on the gestational age, day of life, maternal factors, mode of delivery and site of blood collection. Hemoglobin, HCT & MCV tend to be higher in newborns. They further increase in first 2 days of life. Reticulocytosis and presence of nucleated red cells are normally seen in first week of life. Neonatal anemia is a common problem in NICU. It is usually caused by either hemorrhage or hemolysis and rarely due to decreased production. Hemorrhage can be ante or intra or post natal and it could be external or internal. It could be acute or chronic. Management of acute severe hemorrhage includes packed cell transfusion. Hemolysis is usually due to isoimmune hemolysis, G6PD deficiency or rarely due to the hemoglobinopathy like alpha-thalassemia or due to spherocytosis. Usually patients will have indirect hyperbilirubinemia which needs phototherapy or exchange transfusion. Rarely congenital pure red cell aplasia can present at birth with physical anomalies and anemia. Treatment of neonatal anemia depends on the arteriology.

'NESTROFT'--an effective screening test for beta thalassemia trait.

OBJECTIVE: To evaluate the efficacy of NESTROFT (Naked Eye Single Tube Red Cell Osmotic Fragility Test) as a screening tool for detection of beta thalassemia trait. DESIGN: Prospective study. SETTING: Field camps in various parts of Gujarat and Maharashtra States. METHODS: A total of 2525 subjects were screened. NESTROFT, complete hemogram including red cell indices and calculation of Mentzer's Fraction (MF) and discriminant functions (DF1-4) were done in all subjects. HbA2 was performed in 830 initial subjects to compute sensitivity, specificity and predictive values for various parameters. RESULTS: NESTROFT (sensitivity 94.4%), as a single screening parameter was superior to any of the other evaluated parameters individually, besides being cost effective. Mean corpuscular volume (MCV) < 80 fl followed NESTROFT closely (sensitivity 93.7; p > 0.05). MCV < 75 fl had a significantly (p < 0.001) lower sensitivity (87.3%) in comparison to both of these parameters. In contrast, MF, DF1, DF2, DF3 and DF4 did not meet the requirements of a good screening test with sensitivity values of 66.2%, 54.9%, 47.2%, 64.1% and 55.6%, respectively. NESTROFT in combination with MCV < 80 fl proved 100% sensitive. However, the combination was not cost effective. CONCLUSION: NESTROFT is a sensitive, cost effective, rapid and reliable screening test for detection of beta thalassemia trait in a population.

Evaluation of naked eye single tube red cell osmotic fragility test in detecting beta-thalassemia trait.

The Naked Eye Single Tube Red Cell Osmotic Fragility Test (NESTROFT) was applied to 4 groups of subjects: (i) Normal; (ii) Proven beta-thalassemia trait carriers; (iii) Iron deficiency anemia; and (iv) other hemoglobinopathies, to evaluate its effectiveness as a screening test for beta-thalassemia minor. The test was successful in detecting 105/110 subjects with beta-thalassemia trait. The sensitivity of the test was 95.5% and specificity was 87%. The predictive value of the positive test was 70.5% and that of the negative test was 98.3%. NESTROFT was also positive in 9/17 subjects with HbS trait, in 3/3 subjects with HbD trait and in 1/1 subjects with HbE trait. The test proved to be simple, cheap, easy to perform and adaptable for field surveys, coming close to an ideal screening test for beta-thalassemia minor.