Primary Immune Thrombocytopenia Guidelines for Bone Marrow Aspirate Reduce the Diagnostic Rate of Myelodysplastic Syndromes

About one quarter of patients with low risk myelodysplastic syndromes may present with isolated thrombocytopenia, defined by International Prognostic Scoring System (IPSS) as a platelet (PLT) count < 100 Gi/L. Primary immune thrombocytopenia (ITP) is defined as an acquired immune-mediated disorder characterized by isolated thrombocytopenia, PLT count <100 Gi/L, and the absence of any obvious initiating and/or underlying cause of the thrombocytopenia (Rodeghiero et al, Blood, 2009). Recent guidelines consider bone marrow (BM) aspirate informative in patients > 60 years of age, those with systemic symptoms or abnormal signs or in some cases where splenectomy is considered (Provan et al, Blood, 2009). We performed a retrospective chart analysis between January 2008 and July 2012 of all patients referred to our clinic for thrombocytopenia but with a PLT count 100– 149 Gi/L. The aim of the study was to evaluate whether BM aspirates in these patients be informative.

Twenty-six cases (18 males/8 females) of mean age 59 ± SD 17 years were evaluated at our clinic for a PLT count below normal lab range values, > 100 Gi/L. At the time of evaluation none had bleeding symptoms. PLT counts ranged from 101 to 149 Gi/L, mean 122 Gi/L. Five patients had an enlarged spleen. BM aspirates identified 20 patients with low IPSS risk MDS. Cytogenetics were obtained in 15 cases: 7 normal, 2 del20q, 6 –Y. Twelve patients were aged < 60; 8 (66%) were diagnosed with MDS. Amongst the 14 patients with an indication for BM aspirate (age > 60), 12 (86%) had MDS.

The thresholds of PLT count 100 Gi/L and age 60 years for BM aspirate in patients with isolated thrombocytopenia reduces the diagnostic rate of MDS. In our retrospective review, 66% of patients (younger age and PLT > 100 Gi/L) would not have had MDS diagnosed. BM aspirate should be considered irrespective of age, since more than half of the patients in our case review had MDS with PLT > 100 Gi/L as a single cytopenia and age under 60.

No relevant conflicts of interest to declare.