RELATIONSHIP BETWEEN SINGLE NUCLEOTIDE POLYMORPHISMS IN CYTOKINE GENES AND CLINICAL LABORATORY PARAMETERS IN PATIENTS WITH MULTIPLE MYELOMA

Abstract

Multiple myeloma is the most common form of paraproteinemic hemoblastosis, which is characterized by variability of clinical manifestations, forms, and variants. Limited efficiency of antitumor immune protection in the patient plays an important role in progression of this disease. Survival of myeloma cells is promoted by some growth factors, including a number of interleukins. Cytokines and chemokines are secreted in response to intercellular interactions and stimulate tumor growth, inhibition of osteoblasts and increase of the osteoclastic activity. Cytokine genes show a significant allelic polymorphism. A single gene may exhibit numerous polymorphic sites located in exons, introns and promoter regulatory areas. Single nucleotide substitutions in the promoter region of cytokine genes are known to have a huge impact upon secretion and biological activity of these factors. Therefore, a study of allelic gene variants determining the levels of cytokine production will allow of establishing new immunogenetic factors associated with a high risk of disease development, including multiple myeloma. We have studied single nucleotide polymorphism in cytokine genes (IL-1α -889 TT, IL-1β +3962 TT, IL-6 -174 GG, and IL-6 nt565 GG), and clinical laboratory parameters (serum levels of albumin, β2-microglobulin, and hemoglobin) determining severity grade of multiple myeloma in 80 patients living in the North-Western region of Russia. It was found that the presence of certain cytokine gene variants, i.e., IL-1α -889 TT, IL-1β +3962 TT, IL-6 -174 GG, IL-6 nt565 GG or IL-1α -889 TT, IL- 1β +3962 TT or IL-6 -174 GG, IL-6 nt565 GG was associated with low albumin levels (< 3.5 g/DL), and high levels of β2-microglobulin (> 5.5 mg/l). A combination of all the four negative variants in homozygous state (IL- 1α TT -889, IL-1β +3962 TT, IL-6 -174 GG and IL-6 nt565 GG) increases the chance of six-fold reduction of albumin levels (p < 0.05); combinations of homozygous IL-1α TT -889, IL-1β +3962 TT, IL-6-174 GG. and IL-6 nt565 GG are associated with increased chance of high-level β2-microglobulin (> 5.5 mg/l) by more than two times. This data allow to consider IL-1α -889 TT, IL-1β +3962 TT, IL-6 -174 GG, and IL-6 nt565 GG genotypes additional negative immunogenetic factors in the prognosis of multiple myeloma.

Keywords

• multiple myeloma
• single nucleotide polymorphism
• genes
• interleukins
• albumin
• beta 2-microglobulin