Mean CDR3 length distribution and correlation with viral load. (A) Comparison of mean CDR3 sequence length in the BCR immunoglobulin gene repertoires of 22 HCV-infected patients and 7 healthy individuals (HD), across 4 B-cell subsets. As the 2 biological replicates for each B-cell subset were very similar, the mean of the 2 values was taken for the calculation. Only productive IGHV gene rearrangements were used for this analysis. The mean CDR3 sequence lengths estimated for each B-cell subset for the healthy donors are: naive = 16.51, CD5⁺ = 16.95, CSM = 15.05, NCSM = 14.51. For the HCV-infected patients, the values are: naive = 16.54, CD5⁺ = 17.07, CS memory = 15.47, NCSM = 15.24. Median with interquartile range and P values <.05 are shown (Mann-Whitney U test). (B) Linear relationship between log10-transformed viral load and mean CDR3 length in 22 HCV⁺ patients. Linear regression slopes (m) and 95% confidence intervals (CIs) for the slopes are shown for each B-cell subset. Blue best-fit lines with shaded 95% CIs for the regression lines are also shown. aa, amino acids.