Increased apoptosis of bone marrow cells and preserved proliferative capacity of selected progenitors predict for clinical response to anti-inflammatory therapy in myelodysplastic syndromes (original) (raw)

Objectives. To determine the relation of apoptosis and clonal proliferation in the bone marrow (BM) to the effectiveness of a therapeutic protocol described to downmodulate monokine activity in patients with myelodysplastic syndromes (MDS). Materials and Methods. Prior to protocol therapy, BM stroma was cultivated and selected CD34 ϩ cells were studied in stroma and cytokine-dependent clonogenic assays. The TUNEL assay was used to establish the degree of apoptosis occurring in the marrow and CD34 ϩ population. The effectiveness of oral ciproloxacin 500 mg b.i.d., pentoxifylline 800 mg t.i.d., and dexamathasone 4 mg t.i.d. (CPD) antiinflammatory therapy was correlated with the intensity of cell apoptosis and proliferation of BM progenitor cells. Results. Seventeen patients were studied. Twelve patients (10 transfusion dependent) received therapy for a median of 99 days (range 49-284). Toxicity caused four patients to discontinue the drug combination. Six patients fulfilled response criteria. Four patients became transfusion independent, and 50% reduction in the need for blood transfusions was noted in one patient. Blood parameters of one untransfused patient increased by Ͼ 30%. Blood count remained unsupported in three patients, even at a median of 12 months after trial discontinuation. Apoptosis of marrow cells and selected CD34 ϩ progenitors was detected in a median of 49.5% (range 3.6%-90%) and 10.6% (range 3.6%-100%; p Ͻ 0.01), respectively. In patients who responded to therapy, the median apoptosis rate in the bone marrow population was 71%, in contrast to the nonresponder's rate of 13% (p ϭ 0.002). Overall clonogenic growth of selected precursors corresponded significantly with response to CPD protocol (p ϭ 0.004). Conclusions. In some patients with MDS, ineffective hematopoiesis is related to high apoptotic index despite proliferation of the CD34 ϩ precursors. These patients seem to benefit from CPD cytokine modulatory therapeutic strategy.