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Jacqueline Chabod

Publications and source records attributed to Jacqueline Chabod.

4 recordsLinked to original sources
PubMed2006

Bacterial extract (OM-89) specific and non specific immunomodulation in rheumatoid arthritis patients.

The Escherichia Coli bacterial extract (OM-89) is used in the treatment of rheumatoid arthritis (RA). We evaluated the immunological changes induced by oral administration of OM-89 in 12 RA patients (polyclonal T cell reactivity to PHA, T cell precursor frequencies specific for OM-89 and Tetanus toxoid (TT), a control antigen and the release of Th1 (IFN-gamma, TNF-alpha), Th2 (IL-4) and T regulatory 1 cell (Tr1) (IL-10) cytokines in the supernatants of PBMC cultures. Stimulation index in response to PHA decreased at month 3 as well as T cell precursor frequencies specific for TT with similar trends for OM-89-specific T cell precursor frequencies. OM-89 induced a strong production of IL-10, a significant decrease in IL-4 production while TNF-alpha and IFN-gamma production tended to decrease during the study. Our results suggest that OM-89 has immunomodulatory properties by inducing changes in PBMC cytokines release suggestive of an induced Tr1 response to OM-89.

Aged↗
PubMed2002

Flow cytometric evaluation of pregnancy-induced anti-HLA immunization and blood transfusion-induced reactivation.

BACKGROUND: Pregnancy-induced alloimmunization (PIA) may decrease to a level that becomes undetectable by complement-dependent cytotoxicity (CDC). Nevertheless, such alloimmunization may provoke acute rejections after kidney transplantation and lead to broad-spectrum immunizations after transfusion. Flow-cytometry (FC) was used to estimate the frequency of low-level PIA and to evaluate its influence on posttransfusion alloimmunization profiles. METHODS: To evaluate the frequency of low-level PIA, the sera of 36 women, free of CDC-detectable anti-HLA IgG (CDC-IgG- negative), were cross-matched by FC against their husband's or offspring's lymphocytes and further analyzed with human leukocyte antigen (HLA) Ag-coated microbeads (Flow-PRA One-Lambda, Canoga Park, CA). To evaluate the influence of low-level alloimmunization on posttransfusion appearance of CDC-IgG, pretransfusion sera of a second cohort of 43 women, also CDC-IgG-negative and included in a transfusion protocol, were analyzed by Flow-PRA. Posttransfusion sera were analyzed for the development of cytotoxic IgG. RESULTS: Ten of the first cohort of 36 (27.8%) CDC-IgG-negative women showed a positive FC cross-match against the husband or offspring lymphocytes. Flow-PRA analysis confirmed that 9 of 10 positive cross-matched sera contained anti-HLA IgG. Among the 43 transfused patients, 11 of 16 (68.7%) of the women who were CDC-IgG-positive after blood transfusion showed FC-detectable IgG before transfusion; although 2 of 27 (7.4%) of the patients who remained CDC-IgG-negative after transfusion showed FC-detectable IgG before transfusion (P <0.001). CONCLUSION: Most of the de novo anti-HLA immunizations detected by CDC after transfusion in previously pregnant women can be detected by Flow-PRA before transfusion.

Blood Transfusion↗
PubMed2002

Increased presence of anti-HLA antibodies early after allogeneic granulocyte colony-stimulating factor-mobilized peripheral blood hematopoietic stem cell transplantation compared with bone marrow transplantation.

We have recently shown that the use of allogeneic granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood hematopoietic stem cell transplantation (PBHSCT), as compared with bone marrow transplantation (BMT), is associated with increased titers of antibodies (Abs) directed against red blood cell ABO antigens. To further evaluate the influence of a G-CSF-mobilized PBHSCT graft on alloimmune Ab responses, we examined the frequency of anti-HLA Abs after transplantation in the setting of the same randomized study, comparing PBHSCT with BMT in adults. Anti-HLA Ab presence was determined by complement-dependent cytotoxicity assay (CDC) and flow cytometry in the recipient before and 30 days after transplantation as well as in the donor before graft donation. The use of PBHSCT was significantly associated with increased detection of anti-HLA immunoglobulin G (IgG) Abs early after transplantation as evidenced by flow cytometry (11 of 24 versus 4 of 27 transplant recipients, P =.03) and, less so, by CDC (5 of 24 versus 1 of 27 transplant recipients, P =.09). The difference between PBHSCT and BMT was further heightened when analysis was restricted to anti-HLA IgG Ab-negative donor/recipient pairs. In such a setting, early anti-HLA Ab was never detected after BMT but was repeatedly detected after PBHSCT (flow cytometry, 6 of 18 versus 0 of 17 transplant recipients, P =.02; CDC, 4 of 23 versus 0 of 26 transplant recipients, P =.04). Importantly, the PBHSCT-associated increase in anti-HLA Ab detection was observed despite a reduction in the median number of platelet-transfusion episodes per patient in PBHSC transplant versus BM transplant recipients (3 platelet-transfusion episodes [range, 1-21] in PBHSCT group vs 6 platelet-transfusion episodes [range, 3-33] in the BMT group; P =.02). In conclusion, this study strongly suggests that G-CSF-mobilized PBHSCT results in an increased incidence of circulating anti-HLA Abs and further confirms that the use of such a graft alters alloimmune Ab responses.

Adult↗