MDS with Isolated Neutropenia or Thrombocytopenia. Incidence and Characteristics in the Groupe Francophone des Myélodysplasies (GFM) Registry.

Background: MDS classification is regularly refined over time. WHO classification (2001) puts emphasis on cases with anemia and isolated dyserythropoiesis, as opposed to multilineage dysplasia, while the next modifications to WHO classification will probably consider cases with isolated or predominant granulocytic or thrombopoietic involvement.

Methods: In this context, we analyzed cases of IN and IT included in the GFM registry of MDS.

Results: From Jul 2003 to Jul 2007, 1009 newly diagnosed MDS patients (including 145 therapy MDS, and excluding CMML,) from 11 centers were included in the GFM registry. 22 of them (2%) presented with neutropenia (ANC <1.5×109/l) (IN) and 24 (2.4%) with thrombocytopenia (plts<100×109/l) (IT) as only cytopenia, respectively. IN included 13 F and 9 M and IT 17 F and 7 M. Median age was 70 years (range 54-89) in IN, and 72 years (range 50-84) in IT. Median ANC was 0.89×109 (range 0.14-1.48×109) in IN, and median platelet count 62×109 (range 7-99×109) in IT. According to WHO (2001), IN included 5 RA (diagnosis based in 4 pts and 1 pt on prominent unilineage dyserythropoiesis and unilineage dysmegacaryopoiesis respectively, and elimination of other causes of anemia, as karyotype was normal in all 5 pts), 1 RCMD, 8 RAEB-I, 2 RAEB-II, 1 patient with 5q- syndrome (with Hb=12.5g/dl), 1 unclassified MDS with marrow hypocellularity (of 39 U -MDS in the registry,) and 4 therapy-related MDS. IT included 13 RCMD, 7 RAEB-I, 4 RAEB-II. Cytogenetic findings were: for IN: good risk: 15 (normal: 13, del 5q, -Y), intermediate: 2 (+8), poor: 1, cytogenetic failure: 4 ; for IT: good risk: 13 (normal: 12, del 20q:1), intermediate: 5 (del 2, del3p,+8, del 9+t(9;14), del11+del13p), poor: 2, cytogenetic failure: 4. IPSS was: For IN: low (5), Int-1 (7), Int-2 (5), High (1) patients (4 ND); For IT: low (7), Int-1 (9), Int-2 (4) and High (0) (4 ND). Median follow-up of IN and IT was 23 months (range 2-48 mos). 5 IN pts progressed to AML and 4 of them died, 1 IT pt progressed to AML and 2 died.

Conclusion: IN and IT are rare in MDS, predominate in females, contrary to overall MDS, and are widely distributed in the current WHO classification. IT was always associated with multilineage dysplasia, and/or excess of marrow blasts contrary to some IN, which were therefore more difficult to diagnose, especially as karyotype was usually normal. Follow-up in the GFM registry is still limited to evaluate the prognosis of IN and IT. These findings are to be considered if new specific MDS categories are to be individualized.