Analysis of hematogones, and the correlation of their frequency compared with blood B-cell numbers and age of donors. (A) A relationship between frequencies of hematogones and blood B cells at engraftment (P < .001). (B) A relationship between frequencies of hematogones at engraftment and blood B cells on day 90 (P < .01). (C) A relationship between frequency of hematogones and donor's age in patients who received BMT (blue line, P = .023), and in all recipients treated with either BMT or CBT (black line, P < .001). (D) No significant relationship was observed between frequency of hematogones and recipient age. NS indicates not significant.