CD40LG and Epstein-Barr virus infection: Finally, in two other patients, positive IgM anti-CCP2 titers (393 U/mL and 396 U/mL) were only detected at time point three (70 respectively six weeks after EBV infection); one patient was diagnosed with agenesis of the left side kidney and a hypoplastic kidney on the right side and was HLA-DR3-4 positive, the other was diagnosed with essential hypertension with secondary focal segmental glomerulosclerosis and was HLA-DR2-6 positive.