ABSTRACT
BACKGROUND: The present report illustrates a case with rare "P null" phenotype due to a large deletion in chromosome 22q13.2 and with clinically significant anti-PP1Pk antibody. Patient blood management in such cases is challenging. CASE REPORT: The transfusion center supporting the tertiary care referral center in the southern part of India received a blood sample from a trauma case for pre-transfusion testing. An antibody to a high-frequency blood group antigen was initially suspected. Following extensive immune-hematological workup, the patient was diagnosed to have naturally occurring anti-PP1Pk antibody and a rare "P null" phenotype. The genomic DNA of the patient was analyzed by exome sequencing followed by Sanger's sequencing. Molecular diagnostics revealed a large 21-bp deletion in chromosome 22q13.2 which encodes the A4GALT gene, resulting in truncation of seven amino acids I245-251P and resulted in rare "P null" phenotype. Patient blood management strategies were adopted to manage the patient conservatively without blood transfusion. CONCLUSION: A large deletion in chromosome 22q13.2 had resulted in a rare "P null" phenotype in the present case. The patient was a victim of a road traffic accident, required emergency hospitalization, as well as surgical intervention, and his plasma had antibodies to high-frequency antigens. A rare donor registry plays a major role in providing transfusion support to such cases.
ABSTRACT
A 54-year-old male patient was admitted with low-grade intermittent fever not associated with chills. The cell grouping of the patient sample showed O Rh D positive and serum grouping as B, with a discrepancy to be resolved. Series of immunohematological workup was performed to rule out the discrepancy. Reviewing the past proxy history revealed that the patient blood group was B Rh D positive. Bone marrow aspirate showed hypercellularity with increased myelopoiesis and markedly suppressed megakaryopoiesis giving an impression of acute myeloid leukemia and was confirmed by flow cytometry. Based on the current results and past history the blood group of the patient was confirmed to be B Rh D positive with loss of B and H antigens expression on the red cell surface due to underlying leukemia. Correlating the lab results with the clinical details and the case history is an important step in resolving blood grouping discrepancy.
