B19+p RA patients differ from other (B19+b/p, B19+b and B19−) RA patients and from healthy controls, in that not only do the majority of them not have antibodies to VP-1S and VP-N, but also in that the amount of antibodies to VP-N, VP-1S and VP-2r negatively correlates with age, the amount of antibodies to VP-2r negatively correlates with RF, the amount of antibodies to VP-C negatively correlates with levels of IL-6 and HgB values negatively correlate with levels of IL-4 and IL-6. Here, IL4 is linked to rheumatoid arthritis.