A Prospective, Cross Sectional Study of PNH Clone in MDS Patients Using High Sensitivity Flowcytometry: A Single Center Experience.

Subclinical PNH can be present in patients with bone marrow failure like aplastic anemia and myelodysplastic syndrome (MDS). Such clone may have prognostic and therapeutic implications. In literature around 1-10% MDS cases have shown a PNH clone, however, data from India is relatively scarce. A high sensitivity PNH assay was employed using a single tube combination of FLAER, CD157, CD64, CD15 and CD45 antibodies in adult patients of MDS at presentation. A clone size of  > 0.01% was taken as significant. A total of 30 patients were included. PNH clone was present in 30% cases. Correlation done between PNH clone size and LDH values showed moderately positive correlation (r = 0.735, p = 0.001, r2 = 0.541). As per this study a LDH cut off of 247 IU is likely to predict a PNH clone (> 1%) with moderate sensitivity and specificity. High sensitivity PNH assay is able to detect small PNH clone. Calculating the cut-off of LDH to predict PNH positivity can help us judiciously prescribe this test in MDS patients in resource constrained settings. © Indian Society of Hematology and Blood Transfusion 2019.