Genetic polymorphisms and risk of MALT lymphoma in Greek population

PURPOSE

MALT lymphoma is thought to have a genetic component. Genetic studies in the greek population are rare and genetic determinants remain to be established. The current study aimed to seek correlations between genetic polymorphisms and risk of MALT lymphoma in the Greek population.

PATIENTS AND METHODS

83 MALT lymphoma patients and 60 age-matched healthy outpatients were recruited. SNPs in TNFa, LTA and CTLA-4 genes and IL1RN-VNTR and GSTT1 and GSTTM1 null polymorphisms were genotyped using published PCR/PCR-RFLP methods, while two novel PCR-RFLP methods were developed for IL-22 rs7314777 and TCF19 rs7750641 SNPs. Part of the results was validated by DNA-sequencing. Statistical analysis was performed using SPSS and the SNPstats bioinformatic tool.

RESULTS

The mean age of the patients and controls were 55.9 and 56.2 years respectively. The majority of patients (63) suffered gastric marzinal zone lymphoma (GMZL) and 71.1% were stage I at diagnosis. A statistically significant association was noted for the CTLA-4 49A/ G G variant (OR:2.56,p: 0.006) and the TCF19 rs7750641 SNP T variant (OR: 3.86, p:0.023).

CONCLUSIONS

Our study confirmed a role for CTLA-4 49A/G and TCF19 rs7750641 SNPs in the Greek population. Additional studies could help confirm these associations and possibly link them to prognosis or response to treatment parameters.

Tumor-infiltrating and circulating granulocytic myeloid-derived suppressor cells correlate with disease activity and adverse clinical outcomes in mycosis fungoides

PURPOSE

Cutaneous T cell lymphomas (CTCL) are rare and histologically diverse lymphoproliferative neoplasms, with mycosis fungoides (MF) representing the most common disease subset. Given the emerging role of myeloid-derived suppressor cells (MDSC) as a clinically applicable biomarker in solid tumors, we sought to investigate the presence of tumor-infiltrating and circulating MDSC in early- and advanced-stage MF patients and evaluate their prognostic significance in patient overall survival.

METHODS

Tumor-infiltrating MDSC were assessed immunohistochemically with Arginase-1 in 31 MF and 14 non-MF skin punch biopsies. Circulating MDSC were assessed with flow cytometry in freshly isolated PBMC from 29 MF patients. Granulocytic MDSC (G-MDSC) were defined as CD11b+CD14-CD15+ and monocytic MDSC (M-MDSC) were defined as CD11b+CD14+HLA-DRlow/-.

RESULTS

MDSC infiltration occurred in approximately one-third (35.5%) of CTCL lesions, with a predilection for non-MF lesions (p < 0.05). The predominant morphology of MDSC was granulocytic. Although in MF lesions the presence of MDSC infiltrates did not correlate with clinical stage, it conferred significantly worse overall survival outcomes (p < 0.05). Circulating G-MDSC were significantly higher in MF patients compared to healthy donor controls (p < 0.0001), while M-MDSC did not show any statistically significant difference. G-MDSC were significantly higher in patients with active disease compared to patients who were in partial remission (p < 0.01). As with tumor-infiltrating MDSC, clinical stage did not correlate with circulating G-MDSC levels, while prospective overall survival analysis showed that patients with high levels of circulating G-MDSC have significantly inferior outcomes (p < 0.01).

CONCLUSIONS

This study shows that G-MDSC could represent a novel and easily assessable biomarker in MF, which mirrors disease activity and can predict patient subgroups with aggressive clinical features.