Immune parameters in multiple myeloma patients: influence of treatment and correlation with opportunistic infections.

The present study evaluated cellular and humoral immune parameters in myeloma patients, focusing on the effect of treatment and the risk of opportunistic infections. Peripheral blood lymphocyte subsets and serum levels of nonmyeloma immunoglobulins (Ig) were analysed in 480 blood samples from 77 myeloma patients. Untreated myeloma patients exhibited significantly reduced CD4+/45RO+, CD19+, CD3+/HLA-DR+, and natural killer (NK) cells, as well as nonmyeloma IgA, IgG and IgM. Conventional-dose chemotherapy resulted in significantly reduced CD4+ and even further decline of CD4+/CD45RO+ and CD19+ cells, most notably in relapsed patients. Additional thalidomide treatment had no significant effects on these parameters. Following high-dose chemotherapy (HD-CTX), prolonged immunosuppression was observed. Although CD8+, NK, CD19+ and CD+/CD45RO+ cells recovered to normal values within 60, 90, 360 and 720 days, respectively, CD4+ counts remained reduced even thereafter. Nine opportunistic infections were observed, including five cytomegalovirus (CMV) diseases, one Pneumocystis carinii pneumonia (PCP) and three varicella zoster virus infections with CMV diseases and PCP occurring exclusively after HD-CTX. Opportunistic infections were correlated with severely reduced CD4+, as well as CD4+/CD45RO+ and CD19+ counts. Thus, myeloma patients display cellular and humoral immunodeficiencies, which increase following conventional as well as HD-CTX, and constitute an important predisposing factor for opportunistic infections.

Analysis of commercial CD34 control samples for quality assurance.

The amount of CD34+ cells is important to predict the quality of stem cell transplants and ensure safe engraftment after high-dose chemotherapy. Further, daily controls of the patients' peripheral blood CD34+ cell counts are performed to optimize peripheral blood stem cell collection, especially in patients with low CD34+ cell numbers. Therefore, the use of reliable reference samples is mandatory for quality assurance, both in terms of patient safety and reproducibility of results from different laboratories. We report our first experience with CD-Chex CD34, containing stabilized placental cord blood cells in preservative medium with defined concentrations of CD34+ cells. Analysis was performed according to standard operating procedures. Three lots were tested sequentially on a day per day use. The expected CD34+ values were 28.6-, 36.7- and 28.1 microl(-1), respectively, and the mean measured values were 27.4 +/- 2.75 microl(-1) (n = 25, range 21 - 33 microl(-1), coefficient of variation [CV] 10.0%), 29.9 +/- 2.39 microl(-1) (n = 17, range 26 - 35 microl(-1), CV 8.0%), and 27.2 +/- 2.24 micro1(-1) (n = 18, range 24 - 34 microl(-1), CV 8.2%). Serial dilution (1:2 to 1:10) with normal peripheral blood or PBS w/o Ca++/Mg++ gave adequate results. We conclude that the control samples used in this setting are reliable and thus helpful to increase the accuracy in the analysis of CD34+ cells.