A Study of A1 and A2 Subtypes Among Whole-Blood Donors With Blood Groups A and AB at the Blood Center of a Tertiary Care Institute in Chhattisgarh

INTRODUCTION

The ABO blood group shows various subtypes due to the heterogeneity of A and B alleles. The frequency of these subtypes varies in different populations. Studies related to the frequency of subtypes of blood groups A and AB are lacking in this region. So, we planned this study to estimate the prevalence of A1 and A2 subtypes among the healthy blood donor population.

MATERIALS AND METHODS

This was a prospective study performed in the blood center of a teaching hospital in the Chhattisgarh state. Healthy whole-blood donors were included in the study after written informed consent. The conventional test tube method was used for performing forward and reverse blood grouping. Testing with anti-A1 and anti-H lectin was performed in blood groups A and AB. Additional tests such as saliva testing for secretor status and adsorption-elution were performed if needed.

RESULTS

Four thousand one hundred twelve donor samples were studied, out of which 1170 showed A antigen. Among 1170 samples, 74.6% were blood group A, and 25.4% were AB. Among blood group A, 92.3% were A1 and 3.3% A2, and the rest were other subtypes, while in AB, it was 85.2% A1B and 14.8% A2B. Two cases of anti-A1 antibodies were also noted, which were clinically insignificant.

CONCLUSION

We observed a significantly higher proportion of A2B than A2 in our study population. We also found a large proportion of Aint in the study participants. Testing with anti-A1 and anti-H lectin is recommended in blood groups A and AB to determine various subtypes and prevent any incompatibility.

Factors Influencing Corrected Count Increment After Platelet Transfusion in Thrombocytopenic Patients

Background Platelet transfusion is a life-saving procedure for thrombocytopenic patients. Platelet transfusions can be either prophylactic or therapeutic. Prophylactic platelet transfusion reduces the risk of bleeding before any specific procedure, whereas therapeutic platelet transfusion helps to control active bleeding. Evaluation of the response to platelet transfusion by calculating the corrected count increment (CCI) is important to determine the success of platelet transfusion and to plan subsequent patient management. Methods We conducted a prospective observational study in patients who received at least one unit of platelet concentrate (random donor platelet (RDP) or single donor platelet (SDP)) admitted under or seen by General Medicine. Patients over 60 years, multiparous females, and chemotherapy patients were excluded. The patient's pre-transfusion and post-transfusion platelet counts at one hour and 24 hours were taken, and CCI was calculated. Results We studied 60 patients during the study period, out of which 35 were males (58.33%) and 25 were females (41.67%). The mean age was 36.2 years, and the age range was from 15 to 60 years. The majority of patients were O-Rh positive (41.67%), followed by B-Rh positive (40%), A-Rh positive (11.67%), and least by AB-Rh positive (5%) and only one patient with O-Rh negative (1.67%). The logistic regression analysis showed that sepsis (p=0.025), splenomegaly (p=0.004), COVID-19 (p=0.016), dengue (p=0.028), systemic lupus erythematosus (SLE) (p=0.045), immune thrombocytopenic purpura (ITP) (p=0.003) and fever (p=0.007) significantly contributed to unsuccessful CCI. However, acute leukemia (p=0.238), active bleeding (p=0.147), disseminated intravascular coagulopathy (DIC) (p=0.952), aplastic anemia (AA) (p=0.114), and sickle cell disease (SCD) (p=0.739) did not show any statistical significance. Conclusion Unsuccessful CCI at 24 hours is attributed to non-immunological clinical factors like sepsis, splenomegaly, COVID-19, and fever, whereas immunological clinical factors like SLE, dengue, and ITP resulted in unsuccessful CCI at one hour, as evident by this study.

Central Aortic Cannula Disruption Following Left Atrial Myxoma Excision

Central aortic cannulation is used to give oxygenated blood to the patient through a heart-lung machine. Central aortic cannula disruption during cardiopulmonary bypass (CPB) is a rare complication. This could result in aortic dissection, extensive tears, bleeding, posterior aortic wall injury, oesophageal trauma, and cardiac arrest. We are reporting a central aortic cannula disruption during a left atrium (LA) myxoma excision in which the metal tip part of the cannula detached from its body, resulting in massive blood loss. The intraoperative blood salvage technique was used to maintain hemodynamics during surgery. Pre-procedural visual inspection of all cardiac consumables, including cannula, should be performed to eliminate this complication. All surgical team members should be observant to avoid such complications.

Blood Group Discrepancy in a Whole Blood Donor With Weak AB

The ABO blood group system was the first to be discovered; still, there is an enigma in ABO subgroups. The A₁ and A₂ phenotypes account for about 99% of all A or AB blood group individuals, and the rest are the weaker subgroups. They usually are suspected in cases of blood group discrepancies. Meticulous serological testing with technical expertise will help to differentiate these subgroups. We describe a case of a healthy blood donor with blood group discrepancy due to a weak subgroup of 'A' in the AB blood group.

Blood group discrepancy in mixed-type autoimmune hemolytic anemia in a pediatric patient

Autoimmune hemolytic anemia (AIHA) is characterized by the presence of antibodies directed against self-antigens on red blood cells (RBCs) leading to progressive RBC destruction along with reduced red cell survival. Mixed-type AIHA is characterized by the presence of both warm and cold-autoantibodies. These autoantibodies may cause blood-group discrepancy or cross-match incompatibility leading to delay in arranging suitable blood unit for transfusion. The detection of autoantibodies by monospecific-direct antiglobulin test showing positive reaction on immunoglobulin G and C3d and presence of cold-agglutinins leads to the diagnosis. We report a rare case of mixed AIHA in a 15 years female showing severe anemia, blood group discrepancy, and cross-match incompatibility. She received transfusion of least incompatible packed RBCs without any untoward effect.

Primary Tuberculotic Osteomyelitis of Rib in a Child

Although extremely rare, osteomyelitis has been reported in smaller bones like ribs. A 13-year-old male child presented with a one week history of chest wall swelling. Fine Needle Aspiration Cytology (FNAC) of the lesion and initial bacterial culture could not find the aetiology of the lesion. He underwent surgical resection of entire sixth rib for osteomyelitis and was subsequently diagnosed to have tubercular osteomyelitis. Diagnosis and treatment of rib tuberculosis is both difficult and controversial. Rib tuberculosis is often not successfully treated by medical management alone and consequently needs surgery.