Background and Objectives: Peripheral cytopenia occurs in approximately 2% of the population; however, in up to 0.9%, no cause is identified by conventional tests. Next-Generation Sequencing (NGS) detects somatic variants consistent with clonal hematopoiesis (CH). We aimed to determine the prevalence of CH and pre-myelodysplastic syndrome (pre-MDS) using a 51-gene panel with histopathological assessment. Materials and Methods: Bone marrow samples from 96 consecutive patients evaluated for cytopenia were retrospectively analyzed for genetic alterations. Results: In the overall cohort (n = 96), the median follow-up was 8.1 months (range, 1–20). A total of 37 (39%) out of 96 patients were diagnosed with idiopathic cytopenia of undetermined significance (ICUS), 9 (9%) with clonal cytopenia of undetermined significance (CCUS), 9 (9%) with clonal cytopenia and monocytosis of undetermined significance (CCMUS), 34 (36%) with myelodysplastic syndrome (MDS), and 7 (7%) with myelodysplastic/myeloproliferative neoplasm (MDS/MPN). Among 41 patients in whom no cytogenetic abnormalities were detected by fluorescence in situ hybridization (FISH), somatic variants were identified by NGS. In CCUS, 88% of patients had a single variant, most commonly ASXL1 (44%), followed by TET2 (22%). In CCMUS, ASXL1 and DNMT3A (each 25%) were the most frequent variants. The mean variant allele frequency (VAF) was higher in MDS (33.4%) than in CCUS/CCMUS (13.6%). In MDS patients aged 60 years and older, a higher number of variants were found compared to patients aged less than 60 years (p = 0.028). RUNX1 variants (n = 8) were associated with leukopenia (p = 0.012). Patients with SRSF2 variants (n = 4) had significantly poorer progression-free survival (p = 0.001). EZH2 and SETBP1 variants were associated with inferior overall survival (p = 0.04 and p = 0.019, respectively). In MDS patients (n = 34), thrombocytopenia (plt < 100.000) was associated with shorter PFS (p = 0.005). Conclusions: Given that pre-MDS conditions are considered predictors of hematologic malignancies, conventional diagnostic workup may be insufficient to accurately identify these entities, whereas NGS provides significant additional diagnostic value.
Yücel et al. (Fri,) studied this question.