Clonal expansions of cytotoxic T cells exist in the blood of patients with Waldenstrom macroglobulinemia but exhibit anergic properties and are eliminated by nucleoside analogue therapy.

T cells contribute to host-tumor interactions in patients with monoclonal gammopathies. Expansions of CD8(+)CD57(+) T-cell receptor Vbeta-positive (TCRVbeta(+))-restricted cytotoxic T-cell (CTL) clones are found in 48% of patients with multiple myeloma and confer a favorable prognosis. We now report that CTL clones with varying TCRVbeta repertoire are present in 70% of patients with Waldenström macroglobulinemia (WM; n = 20). Previous nucleoside analog (NA) therapy, associated with increased incidence of transformation to aggressive lymphoma, significantly influenced the presence of TCRVbeta expansions (chi(2) = 11.6; P < .001), as 83% of patients without (n = 6) and only 7% with (n = 14) TCRVbeta expansions had received NA. Clonality of CD3(+)CD8(+)CD57(+)TCRVbeta(+)-restricted CTLs was confirmed by TCRVbeta CDR3 size analysis and direct sequencing. The differential expression of CD3(+)CD8(+)CD57(+)TCRVbeta(+) cells was profiled using DNA microarrays and validated at mRNA and protein level. By gene set enrichment analysis, CTL clones expressed not only genes from cytotoxic pathways (GZMB, PRF1, FGFBP2) but also genes that suppress apoptosis, inhibit proliferation, arrest cell-cycle G1/S transition, and activate T cells (RAS, CSK, and TOB pathways). Proliferation tracking after stimulation confirmed their anergic state. Our studies demonstrate the incidence, NA sensitivity, and nature of clonal CTLs in WM and highlight mechanisms that cause anergy in these cells.

An evaluation of the DiaMed assays for immunoglobulin A antibodies (anti-IgA) and IgA deficiency.

BACKGROUND: Immunoglobulin A antibodies (anti-IgA) are rare but can cause transfusion-associated anaphylaxis. The detection of anti-IgA has traditionally been performed using a labor-intensive hemagglutination assay in a limited number of reference laboratories. STUDY DESIGN AND METHODS: Two simple gel card assays are now available that can be used to screen for anti-IgA and IgA deficiency. A total of 24 serum samples that had been previously assayed for anti-IgA over a 3-year period were used to assess the DiaMed anti-IgA and IgA deficiency assays. RESULTS: The DiaMed assays correctly identified patients (n = 6) who had significant IgA deficiency and anti-IgA. All patients with an abnormal anti-IgA titer by hemagglutination assay and who were also IgA-deficient had anti-IgA detected using the DiaMed screening test. One patient, previously shown to have an IgA level of less than 0.067 g per L, failed to be detected as IgA-deficient in the DiaMed IgA deficiency test; however, anti-IgA were not present. Samples with slightly increased anti-IgA titers tended to have normal IgA levels. CONCLUSION: The DiaMed gel card screening assays are appropriate screening tools for the investigation of transfusion-related anaphylactic reactions and can be used in any routine blood bank laboratory.

Myeloma skews regulatory T and pro-inflammatory T helper 17 cell balance in favor of a suppressive state.

Abstract Discrepancies in the literature between regulatory T cell (Treg) and pro-inflammatory T helper 17 (Th17) numbers in multiple myeloma (MM) can be largely explained by technical differences in methodology and patient selection. In this study, Treg cells were defined as CD3(+)CD4(+)CD25(++)CD127(lo) cells. Patients with MM (n = 20) had a significant imbalance in Treg/Th17 ratio when compared with either aged-matched controls (n = 28) or other monoclonal gammopathies, and this was associated with a significantly worse survival. The percent Treg in bone marrow of patients with MM was higher than that in matched peripheral blood samples (p = 0.02), although FOXP3 expression within bone marrow T cells was lower (p = 0.02). We observed increased Treg function, both in vivo and in vitro, due at least partially to an increase in CTLA-4 expression by concurrent treatment with dexamethasone and immune modulatory compounds (iMiDs). We suggest that immunoregulatory balance is important during active chemotherapy and that conclusions related to the immunostimulatory effect of iMiDs based on in vitro testing must be considered with caution.

Prognostically significant cytotoxic T cell clones are stimulated after thalidomide therapy in patients with multiple myeloma.

The expanded T cell clones are associated with a prolonged survival in patients with multiple myeloma. We sought to confirm this prognostic significance in a multicenter patient cohort and investigate the effect of thalidomide on clones and T regulatory cells (T(regs)). Blood was collected from 120 patients enrolled in a Phase III trial of maintenance therapy +/- thalidomide after autologous stem cell transplantation. TCR Vbeta repertoire analysis identified T cell expansions in 48% of patients pre-transplant and 68% after 8-month maintenance. T cell expansions, previously shown to be clonal, were predominantly CD8+ (93%) and all 24 TCR Vbeta families tested were represented. Thalidomide therapy was associated with a significant increase in the incidence of patients with multiple expansions (49% vs. 23%; chi2 = 6.8; p = 0.01). The presence of expansions regardless of therapy was associated with a significantly longer median progression free survival (PFS) (32.1 vs. 17.6 months; chi2 = 5.6; p = 0.02) and overall survival (OS) (chi2 = 3.9; p < 0.05). Median PFS in the thalidomide arm was 50.9 months for patients with expansions and 28.3 months for patients without expansions (chi2 = 19.4; p = 0.0002). Thalidomide did not appear to modulate T(reg) numbers. Expanded T cell clones are prognostically significant and have an impact on progression after thalidomide therapy in a proportion of patients.