Long‐term kinetics of adult human antibody repertoires

Summary In healthy humans, antibody repertoires change during ontogeny and senescence. The dynamics of antibody repertoires among adults over a longer period of time in one and the same individual has, however, not been extensively studied. In this study we analysed peripheral blood samples from five healthy adults, taken over a period of 10 weeks and once 9 years later. A competitive, quantitative polymerase chain reaction (PCR) was developed to investigate short and long‐term variations in V H gene family repertoires. Serum antibody levels to common self and non‐self antigens were determined in samples taken at the same time‐points as the cell samples to analyse possible correlations between molecular and serological expression profiles. We found a high degree of stability in the V H gene family repertoire over time as well as between individuals with a Caucasian background. A specific change in the usage of primarily the V H 3 and V H 5 gene families was observed in one individual at one time‐point. The deviating pattern resembled the V H gene family utilization pattern observed in naturally activated B lymphocytes. The fluctuations in V H 3 and V H 5 gene family expression correlated with the presence of rheumatoid factor in serum. We discuss the possible influence of polyclonal, transient stimulation of B cells on V H gene repertoires, as measured in circulating B cells.