Early lymphocyte recovery predicts longer survival after autologous peripheral blood stem cell transplantation in multiple myeloma

To understand the prognostic value of lymphocyte recovery after autologous peripheral blood stem cell transplantation (APBSCT), we performed a retrospective study of 59 newly diagnosed multiple myeloma (MM) patients who underwent frontline APBSCT. Conditioning regimens were melphalan 100 mg/m(2) for 2 days. Following APBSCT, all patients showed complete or partial response. Median follow-up time was 29.57 months and median recovery of absolute lymphocyte count (ALC) >= 1000/mm(3) was 23 days. Univariate analysis revealed that significant predictors of overall survival (OS) included bone marrow (BM) plasma cells <= 40% at diagnosis (P = 0.0243) and recovery of ALC >= 1000/mm(3) by day +23 (P = 0.0156). Positive predictors for progression-free survival (PFS) were BM plasma cells <= 40% at diagnosis (P = 0.0134) and recovery of ALC >= 1000/mm3 by day +23 (P + 0.0243). Absolute neutrophil count >= 1000/mm3 on day +12 was marginally significant for OS and PFS (P = 0.0821 and P = 0.1153, respectively). Multivariate analysis showed that ALC >= 1000/mm(3) on day +23 independently predicted OS (P = 0.031) and prolonged PFS (P = 0.011), and that serum beta 2-microglobulin was marginally significant for prolonged OS (P = 0.066). In conclusion, ALC recovery was an independent predictor of both OS and PFS in MM.