Polymorphisms of IL-10, IL-17A, IL-17F and IL-18 Affect the Clinical Features of Multiple Myeloma in Japanese Patients
Authors: Iwasaki Atsushi , Saitoh Takayuki , Ushie Chiaki , Moriyama Norihiko , Takani Tomonori , Hattori Hikaru , Handa Hiroshi , Matsumoto Morio , Isoda Jun , Sawamura Morio , Ogawara Hatsue , Murakami Hirokazu 
Published: October 2019

Abstract
Abstract 4972

Background:
The growth of plasma cells in multiple myeloma (MM) is dependent on a complex interplay among various cytokines, adhesion molecules and other factors in the tumor microenvironment. Several cytokines, including Interleukin (IL)-6, IL-10 and IL-17 have been shown to promote myeloma cell growth in vitro. Furthermore, several investigators have shown the increase in levels of serum IL-6, IL-10, IL-17, and IL-18 in MM patients compared with healthy donors. Although many studies have shown that the dysregulation of these cytokines can be associated with MM development, there are a few reports showing the influence of polymorphisms in cytokine genes on the risk of MM. We examined the single nucleotide polymorphisms (SNPs) of these cytokines: IL-10 (rs1800870 − 1082 A/G, rs1800871 − 819 T/C, and rs1800872 − 592 A/C), IL-17A (rs2275913, −197G/A), IL-17F (rs763780, 7488 T/C), and IL-18(rs187238 −137G/C and rs1946518 −607 A/C) in MM patients, and analyzed the relationship between these SNPs and the susceptibility and clinical features.

Patients and Methods:
Ninety three patients [age range, 35–83 years; male/female 44/49; Durie and Salmon stage I (n=8), stage II (n=22), stage III (n=61), unknown (n=2); International staging system (ISS) 1 (n=21), 2 (n=21), 3 (n=29), unknown (n=22); IgG (n=55), IgA (n=15), IgD (n=2), non-secretory(n=3), Bence Jones(n=18)] with MM and 192 healthy race- and sex-matched healthy controls were examined. Genomic DNA was isolated from peripheral blood using the DNA extraction Kit. Genotyping of IL-10, IL-17A, and IL-17F polymorphisms were determined by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and the genotyping of the IL-18 polymorphism was determined by the allelic specific polymerase chain reaction technique. Genotype and allele frequencies were compared between the study groups using Χ2-test. The characteristics and laboratory features of MM patients with each polymorphisms were compared using Χ2-tests and student t-tests. The Kaplan-Meier method was used in the calculation of overall survival (OS). OS were compared with the log-rank test. Probability values <0. 05 were considered statistically significant.

Results:

Genotype and allele frequencies of cytokines in MM patients and the control:
The frequencies of genotypes of cytokines in patients with MM were as follows: AA 92. 5% and AG 7. 5% for IL-10–1082; TT 43%, TC 48. 4% and CC 8. 6% for IL-10–819; AA 43%, AC 48. 4% and CC 8. 6% for IL-10–592; AA 19. 4%, AG 40. 9% and GG 39. 8% for IL-17A-197; TT 82. 8% and TC 17. 2% for IL-17F; GG 65. 6%, GC 26. 9% and CC 7. 5% for IL-18–137; AA 35. 5%, AC 47. 3% and CC 17. 2% for IL-18–607 loci. No significant differences were observed in the allele or genotype frequencies of IL-10 and IL-17F polymorphisms between MM patients and the control group. However, patients with MM had a significantly higher frequency of the IL-18–137 CC genotype compared to the control group (7. 5% vs. 2. 2%, P<0. 05). The number of IL-18–137 C alleles among the patients with MM was also higher than in the control group (21% vs. 13. 3%, p<0. 05). Furthermore, MM patients had a significantly lower frequency of the IL-17A A/G genotype compared to the control group (40. 9% vs. 58. 7%, P<0. 01).

Patients' characteristics according to cytokine polymorphisms:
IL-10 592 CC genotype (high producer type) was significantly associated with advanced ISS (P=0. 03) and higher β2 microglobulin level (CC vs non CC; 9. 81±4. 78 g/dL vs. 5. 27±3. 27g/dL, p<0. 05). IL-17A-197 AA genotype (high producer type) was also significantly associated with higher bone scale (66. 6% vs 44%, p=0. 05). IL-18–137 CC or GC genotype was significantly associated with advanced ISS (P<0. 05) and lower hemoglobin level (8. 8±2. 6 mg/dL vs. 9. 9±2. 4 mg/dL, p=0. 04). Although there was no significant difference in overall survival of IL17 A, IL-17F and IL-18 polymorphisms, patients with IL-10–592 CC or IL-18–607 AA genotype showedtendency to more unfavorable survival (p=0. 07). A multivariate analysis using cox proportional hazard model demonstrated that Bence Jones protein (p=0. 001), ISS stage III (p<0. 05), the use of new drugs (p=0. 001), IL-10–592CC genotype (P=0. 005) and IL-17 AA (P=0. 00001) were independent adverse prognostic factors.

Conclusion:
These results indicate that cytokine polymorphisms, including IL-10, IL-17 and IL-18, are associated with prevalence and clinical feature of MM in Japanese patients.

Disclosures:
No relevant conflicts of interest to declare.