Patients carrying the STAT4 rs7574865 variant allele have a higher risk to develop the monoclonal component and leukopenia (P = 0.002, OR = 7.6; P = 0.048, OR = 2.01, respectively), while patients carrying the variant allele of TRAF3IP2 rs33980500 were less predisposed to develop anti-SSB (OR = 0.4 and P = 0.043). This evidence concerns the gene STAT4 and Decreased total leukocyte count.