IL-10 promoter and IL4-Ralpha gene SNPs are associated with immediate beta-lactam allergy in atopic women.

BACKGROUND: Allergic reactions to beta-lactam antibiotics represent the most frequent cause of immunological drug reactions. OBJECTIVE: This study evaluates the involvement of genetic susceptibility factors in patients with immediate allergic reactions to beta-lactams. We examined 15 single nucleotide polymorphisms (SNP) of genes coding proteins implicated in immunoglobulin (Ig)E synthesis regulation. METHODS: We performed a case-control study involving 44 patients with immediate beta-lactam allergy and 44 control subjects, all matched for sex and atopy. Interleukin (IL)-4, IL-13, IL-4Ralpha, signal transducer and activator of transcription 6 (STAT6), interferon (IFN)-gammaR1, IFN-gammaR2 and FcepsilonRIbeta gene polymorphisms were determined using polymerase chain reaction (PCR) restriction fragment length polymorphism, and IL-21R gene and IL-10 promoter polymorphisms by direct sequencing. RESULTS: Our analysis did not reveal differences in the distribution of the 15 SNPs between allergic patients and controls. However, among atopic subjects, we found two distinct significant associations between immediate beta-lactam allergy in women and the Ile75Val variant of IL-4Ralpha gene (P = 0.012, OR = 5.4, CI: 1.16-27.7), and two linked IL-10 promoter gene polymorphisms, -819C>T and -592 C>A (P = 0.023, OR = 17.5, CI: 1.26-533.07). In contrast, we observed no association in allergic male subjects in the atopic population. Interestingly, the IL-4Ralpha Ile75Val variant could have a paradoxal protective effect in atopic male patients (P = 0.004, OR = 0.07, CI: 0.01-0.66). CONCLUSION: Our findings suggest that polymorphisms in the IL-10 promoter and IL-4Ralpha genes are genetic factors that favour beta-lactam immediate allergies in female patients with atopy.

CD4 T cell surface CCR5 density as a host factor in HIV-1 disease progression.

OBJECTIVE AND DESIGN: We have recently shown that the number of CCR5 molecules at the surface of peripheral blood CD4 T cells (CCR5 density) correlates with the viral RNA plasma level in HIV-1-infected individuals. As viral load is a strong predictor of outcome in HIV infection, the present study examines the correlation between CCR5 density and HIV-1 disease progression. METHODS: Using a quantitative flow cytometry assay, we measured CCR5 density in HIV-1-infected adults and control healthy volunteers. The CCR5 genotype (presence of a Delta 32 allele) was also determined. RESULTS: CCR5 density was stable over time on non-activated, HLA-DR(-)CD4 T cells of infected individuals. In a study cohort of 25 patients, asymptomatic and non-treated, we observed a correlation between CCR5 density on HLA-DR(-)CD4 T cells and the CD4 T cell slope (P = 0.026), which was independent of the presence or absence of the Delta 32CCR5 deletion. In particular, slow progressors expressed lower CCR5 densities than non-slow progressors (P = 0.004) and non-infected control subjects (P = 0.002). CONCLUSION: These results are compatible with the hypothesis that CCR5 density, which is a key factor of HIV-1 infectability, determines in-vivo HIV production, and thereby the rate of CD4 cell decline. Consequently, CCR5 density quantitation could be a new valuable prognostic tool in HIV-1 infection. Moreover, these data emphasize the therapeutic potential of treatments that reduce functional CCR5 density.

Reduced intensity conditioning: enhanced graft-versus-tumor effect following dose-reduced conditioning and allogeneic transplantation for refractory lymphoid malignancies after high-dose therapy.

Non-myeloablative regimens have been proven to allow engraftment following allogeneic stem cells transplantation (allo-SCT) with minimal procedure-related toxicity. Conventional allo-SCT may produce remissions in patients with relapsed and refractory lymphoid malignancies (LM) but these good results may be achieved at the cost of high treatment-related morbidity and mortality. Application of allo-SCT using less intensive regimens may temper the frequency of these complications, allowing a potent graft-versus-tumor effect (GVT). We present our data on 11 patients with LM receiving allo-SCT with a reduced regimen. Ten patients had received previous high-dose therapy, and were at high risk for toxicity, thus precluding the use of allo-SCT. A fludarabine and low-dose busulfan combination facilitated engraftment while exerting GVT. Hematological recovery was quick, and full donor T cell chimerism preceded acute GVHD. GVHD and infections were the major problems. Spontaneous acute GVHD occurred in eight patients (72%). Five patients (45%) achieved complete remission, and the GVT effect was closely associated with GVHD. These results support the concept that GVT is effective against LM in patients who have been heavily pretreated. Further studies are needed to investigate strategies to generate more specific alloreactive effects providing optimal GVT and an acceptable risk of GVHD and infections.

CD4+ T cell surface CCR5 density as a determining factor of virus load in persons infected with human immunodeficiency virus type 1.

The intensity of expression of the chemokine receptor CCR5 is involved in in vitro cell infectability by human immunodeficiency virus (HIV)-1 R5 isolates. Because CCR5 expression varies among individuals, the hypothesis that this expression could determine virus load in HIV-1-infected persons was tested. The mean number of CCR5 molecules per cell was measured on peripheral blood CD4+ T lymphocytes (CCR5 density) from HIV-1-infected, asymptomatic, nontreated adults. There was a strong correlation between HIV RNA plasma level and CCR5 density (P=.009) that was independent of cell activation and was not due to an HIV-induced CCR5 up-regulation. These data are compatible with the hypothesis that CCR5 density is a key factor governing cell infectability and in vivo virus production and explain the protective effect of the Delta32CCR5 deletion, which results in low CCR5 expression. CCR5 density might be of critical predictive value in HIV infection.

Polymorphism of the HLA-DMA and DMB genes in rheumatoid arthritis.

OBJECTIVE: To determine whether the HLA-DMA and DMB genes, whose encoded molecules are involved in HLA class II-restricted antigen presentation, contribute to the genetic susceptibility to rheumatoid arthritis (RA). METHODS: One hundred ninety-one RA patients, 147 control subjects, and 218 HLA-DRB1 genotype-matched control subjects were oligotyped for DMA and DMB genes. RESULTS: DMA*0103 and DMB*0104 were significantly increased in the RA patients compared with the randomly selected and the matched controls, thus indicating a direct influence of the DM genes. After stratification of the patients and matched controls according to DRB1 genotypes, only DMA*0103 was increased in the RA patients with DRB1*01, as well as in the patients negative for the RA-susceptibility DR alleles. CONCLUSION: Our results suggest that DMA*0103 could play an additional role in the genetic susceptibility to RA.

Generic HLA-DRB1 gene oligotyping by a nonradioactive reverse dot-blot methodology.

HLA-DRB1 allelic specificities can be determined using SSOs annealing to their complementary PCR-amplified target DNA. To perform HLA-DR oligotyping routinely for donors and recipients of bone marrow transplantation, a "reverse" dot-blot technique has been developed that consists in the hybridization of labeled PCR-amplified target DNA to SSOs that have been first attached to nitrocellulose membranes. The 15 oligonucleotides chosen enabled the following HLA-DRB1 "generic" specificities to be defined: DR1, BON, 2, 3, 4, 11, 11 JVM, 12, 13, 13 HAG, 14, 7, 8, 9, 10. The genomic DNA was amplified by asymetric PCR with incorporation of biotinylated deoxynucleotides predominantly to generate labeled single-stranded DNA. Hybridization between specific immobilized oligoprobes and target DNA was nonradioactively detected by a colorimetric reaction using alkaline phosphatase. The reverse dot-blot methodology was successfully tested, first, for the determination of HLA-DR4 subspecificities, and then the procedure was routinely applied to the generic HLA-DR oligotyping of bone-marrow donors and recipients.