Frequency Of CD34 Expression In Acute Lymphoblastic Leukaemia And Its Correlation With Clinicopathological Characteristics: A Single Centre Experience From Pakistan.

Background: This study was carried out to determine the frequency of CD34 positivity in acute lymphoblastic leukaemia (B-ALL) in our population and to report its association with the clinicopathological profile at the time of diagnosis. Methods: The cross-sectional study was conducted at National Institute of Blood Diseases and Bone Marrow Transplantation, Karachi, Pakistan, from March 2020 till December 2020.Newly diagnosed patients were selected, from both genders and all age groups. Relevant history and findings of physical examination were recorded. Immunohistochemistry was done on trephine biopsy and molecular studies were carried on bone marrow aspirates or peripheral blood samples. Results: Out of 105 patients enrolled, 67 (63.8%) were males, with a male to female ratio (M: F) 1.8:1. Of the total patients, 62 (59.04%) were above 15 years of age. CD34 was expressed in 73 (69.5%) cases. Lymphadenopathy, splenomegaly, and hepatomegaly were separately noted in context to CD 34 expression in 22 (66.6%), 24 (64.8%), and 14 (58.3%) patients, respectively. CNS disease was seen in a total of 3(2.75%) subjects, in which 2 (66.6%) of the patients had CD34 expression. Total 81 patients in our study fall into the high-risk group out of which CD 34 expression was seen in 58(71.6%) subjects. Cytogenetic analysis, BCR-ABL p190, and MLL gene rearrangement were investigated in all participants. Cytogenetic analysis revealed an abnormality in 20 (19%) cases out of which 13 (17.8%) cases were from CD34 positive group. Conclusion: Our study reported CD34 expression in more than two-thirds of cases. High-risk disease was significantly associated with CD34 expression.

Highly specific functional equivalence of XN-HPC for optimum CD34+ cell count in harvested allogeneic bone marrow stem cell products.

OBJECTIVES: To establish a reliable XN-HPC cutoff, for an effective CD34 + cell count of ≥2 × 106cells/kg of the recipient's body weight, in harvested bone marrow products in allogenic transplantation. METHODS: The study was carried out in two phases. In retrospective Phase 1, data from 47 donors were analyzed. Sysmex analyzer XN-20 and BD FACS Calibur were employed to process XN-HPC and CD34 + cell enumeration, respectively. To make the two variables comparable, both XN-HPC and CD34 + cell counts were reported as the number of cells/kg of the recipient's body weight. Spearman's rank correlation coefficient was calculated for CD34 + cells and XN-HPC, followed by the calculation of the receiver operating characteristic (ROC) curve to identify the XN-HPC value which could effectively predict the cutoff of ≥2 × 106 CD34 + cells/kg of the recipient's body weight. In Phase 2, the computed XN-HPC cutoff was validated in a prospective set of 53 donors by obtaining the positive and negative predictive values. RESULTS: Statistically significant correlation was obtained between XN-HPC and CD34 + cell count with Spearman's rho of 0.54 (p-value <0.001). The optimal XN-HPC cutoff, for the required CD34 + ve cell count of ≥2 × 106 cells/kg of the recipient's body weight, was calculated to be ≥2.80×106 cells/kg of the recipient's body weight with the specificity and sensitivity of 100% and 31%, respectively. The ROC curve demonstrated the area under the curve to be 0.74. Phase 2 validation revealed 100% PPV. CONCLUSIONS: For harvested bone marrow products with XN-HPC of ≥2.80×106 cell/kg of the recipient's body weight, CD34 + cell enumeration by flow cytometry can safely be disposed of.