Seroprevalence of SARS-CoV-2 IgG antibody among healthy blood donors: a single centre study.

BACKGROUND: Severe acute respiratory syndrome corona virus 2(SARS-CoV-2), the causative agent of corona virus disease-2019(COVID- 19) which has led to a global pandemic. The true extent of the burden of COVID-19 may be underestimated, and there is need to know the current prevalence of SARS-CoV-2 antibody in population. METHODS: The present study was a cross-sectional study to assess prevalence of SARS-CoV- 2 IgG antibody among 586 healthy voluntary blood donors who donated whole blood between mid-December 2020 to January 2021. A chemiluminescence assay was used to detect the presence of SARS-CoV-2 IgG antibody in serum samples in addition to recommended transfusion transmitted infections tests and Signal to Cut Off (S/C) > 1 was considered as reactive for antibody as per manufacturer's instructions. RESULTS: In the present study, 586 healthy voluntary blood donors were enrolled and were screened for SARS- CoV-2 IgG antibody. Out of 586 donors, 52 donors had indeterminate values of SARS-CoV-2 IgG antibody. A total of 534 healthy voluntary blood donors' samples were included in the present study for analysis. Out of total 534 healthy blood donors, 42.88% (229) were found to be seropositive while 57.11% (305) were found to be seronegative. CONCLUSION: A 43% positivity of SARS-CoV-2 IgG antibody among healthy blood donors was detected which is an indication of presence of infection at community level and majority of the population already has been exposed to SARS-CoV-2 infection. However, there was no statistically significant association of type of blood group and age with seropositivity.

Identification of the novel HLA-B*49:01:01:22 allele in an Indian renal transplant donor by next generation sequencing.

HLA-B*49:01:01:22 differs from HLA-B*49:01:01:01 by a single nucleotide C->G change in intron 5 at gDNA 2451.

Prevalence of anti-HLA antibodies in COVID-19 convalescent plasma donors: an Indian experience.

BACKGROUND: COVID-19 convalescent plasma is one of the experimental therapies used widely in moderately sick COVID-19 patients. However, there are a few risks involved in plasma transfusion; notably, transfusion-related acute lung injury (TRALI) caused by antibodies against human leukocyte antigens (HLA). This study was designed to assess the prevalence of anti-HLA antibodies in convalescent plasma donors using the single antigen bead method. STUDY DESIGN AND METHODS: This was a hospital-based observational study of consecutive plasma donors. A total of 252 samples were screened for anti-HLA Class I and Class II antibodies using the microbead assay with the identification of anti-HLA Ab in positive samples being performed using a single antigen bead assay. Luminex-based normalized background cutoff ratios of 10.8 for Class I and 6.9 for Class II and mean fluorescence intensity cutoffs of 2500 for Class I and 1500 for Class II were used for screening and the single bead assay, respectively. RESULTS: Of 252 screened samples, 28 (11.1 %) were positive for Class I, Class II or both Class I and Class II anti-HLA antibodies in donors with no history of a previous immunizing event. Moreover, 20/252 (7.9%) donors without any history of prior immunization had specific anti-HLA antibodies of Class I or Class II or both by the single bead assay. CONCLUSIONS: The high prevalence of anti-HLA antibodies in our cohort of donors raises an urgent and immediate need for anti-HLA antibody screening in all convalescent plasma donors for safe therapy of COVID-19 patients.

Identification of the novel allele, HLA-A*01:01:01:92, in an individual from North India.

HLA-A*01:01:01:92 differs from HLA-A*01:01:01:01 by a single nucleotide G->C change at gDNA-56 position.

The correlation of spurious eosinophilia in automated hematological analyzer Sysmex XS-800i with Plasmodium infection diagnosis.

CONTEXT: Automated analyzers based on flow cytometry have evolved as an effective adjuvant diagnostic tool in malaria diagnosis. AIM: To find out the correlation of interpretive (IP) message from automated hematology analyzer XS-800i and Plasmodium infection diagnosed in peripheral smear. SETTINGS AND DESIGN: Prospective study carried over a period of 2 years (July 2010 to June 2012). MATERIALS AND METHODS: All cases with IP message of eosinophilia in Sysmex XS-800i analyzer were screened for microscopic correlation of eosinophilia and other peripheral smear findings. RESULTS: In 24 out of 5012 patients with eosinophilia, microscopic eosinophil counts were normal. In these 24 cases, IP message in hematology analyzers was that the eosinophilia and WBC scattergram showed narrowed space between the eosinophil and neutrophil population. On careful examination of the peripheral smears of all 5012 cases, 39 cases revealed different stages of Plasmodium vivax (trophozoites, schizonts or gametocytes) in erythrocytes. CONCLUSION: Peripheral smears of the cases having inconsistent eosinophilia result with that of Sysmex XS-800i analyzer should be examined carefully for the presence of malaria parasites in the red blood cells. Sysmex XS-800i analyzers have moderate range of sensitivity and high degree of specificity in diagnosing malaria as spurious eosinophilia.