Evaluation of multiparametric flow cytometry in diagnosis & prognosis of myelodysplastic syndrome in India.

Background & objectives: Diagnosis of myelodysplastic syndromes (MDS) is subjective in low-grade cases with <5 per cent blasts or <15 per cent ring sideroblasts. Flow cytometry (FCM) has been used to diagnose MDS; but, it still has only an adjunctive role. This study was conducted to evaluate the role of FCM to diagnose MDS and correlate the number of aberrancies with revised international prognostic scoring system (R-IPSS). Methods: This study included 44 consecutive clinically suspected cases of MDS with refractory cytopenia(s) and 10 controls. Patients were divided into two groups: (i) proven MDS cases (n=26), and (ii) suspected MDS (n=18). Ogata quantitative approach, pattern analysis and aberrant antigen expression were studied. Results: Ogata score ≥2 correctly diagnosed 80.7 per cent (21/26) while aberrant antigen and pattern analysis with flow score of ≥3 could diagnose 92.3 per cent (24/26) patients with proven MDS. Combination of both with flow score ≥3 could diagnose 100 per cent patients. Eight patients in suspected MDS group with persistent cytopenia on follow up were labelled as probable MDS. Ogata score ≥2 was present in 5 of 8 and pattern analysis score ≥3 was present in six probable MDS patients. Combination of both with flow score ≥3 was present in seven of eight patients. Spearman's correlation between Ogata score and R-IPSS, pattern analysis and R-IPSS and combination of both scores and R-IPSS showed significant positive correlation in proven MDS as well as when proven and probable MDS patients were combined. Interpretation & conclusions: Our results showed that combined Ogata approach and pattern analysis, demonstration of ≥3 aberrancies in >1 cell compartment could diagnose most MDS patients. Patients with high flow scores had high R-IPSS scores. Patient with flow score ≥3 and borderline cytomorphology should be observed closely for the development of MDS.