TNF-alpha mediated apoptosis of the hematopoietic cells has been thought to contribute to the ineffective hematopoiesis observed in myelodysplastic syndrome (MDS). The combination of pentoxifylline (P) and ciprofloxacin (C) has been shown to reduce the serum levels of TNF-alpha, and an earlier trial of P and C with dexamethasone (D) provided good palliation for patients with MDS. The purpose of this study is to assess the hematologic response to PCD therapy for patients suffering with MDS. 21 of 25 patients who completed at least of 12 weeks of treatment were evaluable for the treatment efficacy. At baseline, the patient's median age was 60 yr (range: 18-75 yr). The diagnoses according to WHO classification included: RA (n=5), RCMD (n=10), RARS (n=1), RCMD/RS (n=1), RAEB (3), and CMML (n=1). 11 patients (52%) had at least single lineage response. 3 patients (11%) showed improvement of triple lineage cytopenia. There were no differences in the response rates between the FAB subtypes. The median time to response was 4 weeks (range: 2-12 weeks), and it is interesting that 9 of 11 patients who had a response remained without relapse for a median of 177 days (range: 78-634 days). These preliminary results indicate that anti-cytokine therapy with PCD is an effective and well tolerated palliative treatment for patients with MDS.
Adolescent ; Adult ; Aged ; Anti-Infective Agents/adverse effects/therapeutic use ; Anti-Inflammatory Agents/adverse effects/therapeutic use ; Apoptosis/*drug effects ; Ciprofloxacin/adverse effects/therapeutic use ; Comparative Study ; Dexamethasone/adverse effects/therapeutic use ; Drug Therapy, Combination ; Erythrocyte Count ; Female ; Hematologic Agents/adverse effects/therapeutic use ; Humans ; Male ; Middle Aged ; Myelodysplastic Syndromes/*blood/drug therapy ; Nausea/chemically induced ; Pentoxifylline/adverse effects/therapeutic use ; Platelet Count ; Time Factors ; Treatment Outcome ; Tumor Necrosis Factor-alpha/*metabolism

BACKGROUNDCigarette smoke-induced emphysema is associated with overexpression of the chemokine receptor CXCR3 and its ligands. Previously, we have demonstrated that pentoxifylline (PTX) alleviated cigarette smoke-induced emphysema. The aim of this study was to determine if the overexpression of CXCR3 and its ligand interferon-inducible protein-10 (IP-10) that was elicited by smoke exposure were attenuated by PTX.

METHODS(1) The study in vitro: a given number of RAW264.7 macrophages with decreasing concentrations of PTX in the culture medium were challenged with cigarette smoke extract (CSE); (2) The study in vivo: male BALB/c mice were randomized into four groups, i.e., sham-smoke, smoke only, smoke with 2 mg/kg PTX, and smoke with 10 mg/kg PTX. The smoke exposure time was 90 minutes once a day, 6 days a week for 16 weeks. PTX was given intraperitoneally before each episode of smoke exposure. Interferon (IFN)-γ and IP-10 in broncho-alveolar lavage fluid (BALF) and in culture medium were measured by enzyme-linked immunosorbent assay (ELISA). IP-10 mRNA in lung tissue was assessed by RT-PCR. CXCR3 positive cells in lung sections were visualized by immunochemistry staining.

RESULTSUp-regulation of IFN-γ and IP-10 in the culture medium of macrophages elicited by CSE was inhibited by PTX in a dose-dependent manner. Chronic cigarette smoke exposure led to overexpression of IFN-γ and IP-10 in BALF, upregulation of IP-10 mRNA and increased infiltration of CXCR3(+) cells into lung parenchyma. Administration of PTX decreased the level of IFN-γ from (6.26 ± 1.38) ng/ml to (4.43 ± 0.66) ng/ml by low dose PTX or to (1.74 ± 0.28) ng/ml by high dose PTX. IP-10 was reduced from (10.35 ± 1.49) ng/ml to (8.19 ± 0.79) ng/ml by low dose PTX or to (7.51 ± 0.60) ng/ml by high dose PTX. The expression of IP-10 mRNA was also down-regulated (P < 0.05). But only with a high dose of PTX was the ratio of CXCR3(+) cells decreased; 15.2 ± 7.3 vs. 10.4 ± 1.8 (P < 0.05).

CONCLUSIONPTX attenuates cigarette smoke-induced overexpression of chemokine receptor CXCR3 and its ligand IP-10, which is relevant to its inhibitory effect on pulmonary emphysema.

Animals ; Cell Line ; Chemokine CXCL10 ; genetics ; metabolism ; Gene Expression ; drug effects ; Immunohistochemistry ; Male ; Mice ; Mice, Inbred BALB C ; Pentoxifylline ; pharmacology ; therapeutic use ; Pulmonary Emphysema ; drug therapy ; genetics ; metabolism ; Random Allocation ; Receptors, CXCR3 ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Smoking ; adverse effects