Dysregulation of immune cell and cytokine signaling correlates with clinical outcomes in myelodysplastic syndrome (MDS)

OBJECTIVES

Myelodysplastic syndromes (MDS) are characterized by ineffective hematopoiesis. Although hypomethylating agents (HMA) have improved survival in higher-risk MDS, most patients eventually succumb to progressive disease. Utilizing samples collected prospectively from three MDS clinical trials, we analyzed genetic and immunological biomarkers and correlated them with clinical outcomes.

METHODS

154 samples were analyzed from 133 de novo MDS patients for T-cell and myeloid cell immunophenotyping and gene expression analysis. Treatments were with HMA or immunomodulatory drug (IMiD) alone or in combination.

RESULTS

We observed differences in immune cell subsets between lower and higher risk IPSS groups with NKT cells, MDSCs, intermediate-proinflammatory and non-classical monocytes being higher in the latter group while naïve CD4+ T-cells were reduced. Intermediate-proinflammatory monocytes were increased in non-responders and those failing to achieve at least a hematological improvement. Pro-inflammatory NKT cells were increased at diagnosis for patients failing to derive clinical benefit after 12 months of treatment. Gene expression analysis of paired bone marrow (BM) colony-forming units (CFUs) from diagnosis and 4 cycles post-treatment confirmed that genes involved in cytokine signaling were downregulated in C4 normal colonies.

CONCLUSIONS

These findings support the central roles of dysregulation in innate immunity and inflammatory signaling in the pathogenesis of MDS which correlated with clinical outcomes post-treatment.

When should iron chelation therapy be considered in patients with myelodysplasia and other bone marrow failure syndromes with iron overload?

Despite the absence of a robust evidence base, there is growing consensus that effective treatment of iron overload leads to decreased morbidity and premature mortality in patients with good prognosis myelodysplastic syndromes (MDSs). Furthermore, new treatment modalities, including disease-modifying therapies (lenalidamide and azacytidine) and reduced intensity conditioning therapies for allogeneic blood stem cell transplants, are offering the prospect of longer survival for patients with traditionally less favourable prognosis MDS, who might also benefit from iron chelation. This article proposes assessment of patients with MDS and related bone marrow failure syndromes to determine suitability for iron chelation. Iron chelation therapy options and monitoring are discussed.

Current status of new drugs for the treatment of patients with multiple myeloma

Multiple myeloma, a malignant disorder of plasma cells, is the second most common haematological malignancy. Although treatable, multiple myeloma remains incurable in virtually all cases, with a median survival of 3-4 years. Fortunately for patients with this disease, traditional treatment paradigms have been challenged with the emergence of a number of new therapies entering clinical practice over the last 6 years. In this review, we focus on the use of thalidomide (Thalidomide Pharmion; Boulder, CO, USA), lenalidomide (Revlimid; Celgene Corporation, Summit, NJ, USA) and bortezomib (Velcade; Janssen Pharmaceutica N.V., Belgium) in the treatment of myeloma. We present the current clinical experience with respect to efficacy and toxicity of these promising new agents and how the incorporation of these drugs with traditional therapies may improve the outcome for patients with multiple myeloma.

Differentially expressed messenger RNA isoforms of the human estrogen receptor-alpha gene are generated by alternative splicing and promoter usage

The isolation and characterization of several new human estrogen receptor-alpha (hERalpha) mRNAs are described. Together with those previously identified, they give rise to a total of six hERalpha mRNA isoforms (A-F hERalpha mRNAs). Produced from a single hERalpha gene by multiple promoter usage, all these transcripts encode a common protein but differ in their 5'-untranslated region as a consequence of alternative splicing of five upstream exons (1B-1F). RT-PCR and S1 nuclease mapping analysis of these different hERalpha mRNA isoforms revealed a differential pattern of expression of the hERalpha gene in human tissues and cell types. The A hERalpha mRNA is the main isoform detected in mammary glands or in the tumor cell lines derived from this tissue. In endometrium, the predominant forms are the A and C hERalpha mRNA isoforms, whereas the C and F hERalpha mRNA isoforms are the major forms detected in ovary. Finally, high levels of the E hERalpha mRNA isoform are restricted to the liver with an increased expression in females. Taken together, our results demonstrate that the hERalpha gene is a complex genomic unit exhibiting alternative splicing and promoter usage in a tissue-specific manner.

Flecainide acetate for conversion of acute supraventricular tachycardia to sinus rhythm

The efficacy of intravenous flecainide acetate (maximum 2 mg/kg or 150 mg given at a rate of 15 mg/min) was assessed in patients with acute supraventricular tachycardia (SVT) (within 24 hours). Fifty patients were studied, 46 with spontaneous SVT and 4 with induced SVT at electrophysiologic assessment. Conversion to sinus rhythm was achieved within 45 minutes in 76%: in 25 patients with atrial fibrillation (76% conversion), 15 with atrioventricular (AV) nodal or AV reentrant tachycardia (100% conversion) and 10 with atrial flutter or atrial reentrant tachycardia (40% conversion). Adverse effects were noted in 21 patients (42%): paresthesia in 9, drowsiness in 8, nausea in 2, accelerated ventricular rate in 5, ventricular tachycardia in 1, sinus bradycardia in 1 and hypotension in 5. Adverse effects were associated with larger dosage and atrial flutter or atrial reentrant tachycardia. Thus, flecainide acetate is effective in converting to sinus rhythm acute atrial fibrillation and AV nodal and AV reentrant tachycardias, but not atrial flutter or atrial reentrant tachycardia.