The Clinical Significance of CD371 Expression Detected by Flow Cytometry in Primary Myelofibrosis.

OBJECTIVE:This study aims to analyze the expression patterns of CD371 in CD34+CD117+ bone marrow (BM) cells from patients with primary myelofibrosis (PMF) using flow cytometry (FCM), with a comparative evaluation against conventional antigens to assess its potential clinical utility for identifying aberrant immunophenotypes in PMF. METHODS:A retrospective analysis was conducted on BM samples from 26 PMF patients and 20 control individuals. We evaluated the proportions of CD34+CD117+ cells and basophils, as well as the expression profiles-including positive cell percentages, mean fluorescence intensity (MFI), and coefficient of variation (CV) of MFI-of CD371, CD34, CD117, CD13, CD33, CD123, CD38, HLA-DR, and CD7 within the CD34+CD117+ population. RESULTS:Control group exhibited consistent bimodal CD371 expression, while PMF samples showed three distinct patterns. PMF demonstrated significant differences vs. controls in CD371 MFI (p < 0.01), MFI CV (p < 0.01), and CD371+ cell proportion (p < 0.05). Within CD371+ cells, MFI and MFI CV also differed significantly (both p < 0.01). Significant differences (p < 0.01) were observed in: CD34+CD117+ proportion, CD34 MFI/MFI CV, basophil proportion, CD38dim+ proportion/CD38 MFI/MFI CV. No significant differences were observed for CD13+ cell proportion (p = 0.154) or CD13 MFI (p = 0.835), though the MFI CV was significantly different (p < 0.01). CD33+ cell proportion (p < 0.05) and CD33 MFI (p < 0.05) showed significant differences, while the MFI CV did not (p = 0.276). CONCLUSION:This study provides the first characterization of CD371 expression patterns in PMF, showing significantly different expression profiles compared to controls. While CD371 demonstrated comparable performance to standard markers (CD34/CD38/CD13/CD33) and showed better discrimination than CD123/HLA-DR, these preliminary findings suggest its potential utility for: (1) identifying abnormal CD34+CD117+ populations in PMF, and (2) possible integration into routine clinical workflows, pending further validation in larger cohorts.