RESUMO
BACKGROUND: HLA antibodies passively transferred to transfused recipients may cause transfusion reactions such as transfusion-related acute lung injury (TRALI), but in many of the reported TRALI incidents, no white blood cell antibodies have been identified. We investigated whether a higher number of anti-HLA would be detected in donor's plasma by using a method with potential higher sensitivity rate. STUDY DESIGN AND METHODS: Sera from 300 previously pregnant female blood donors were screened for anti-HLA using a solid-phase mixed-antigen assay (enzyme-linked immunosorbent assay [ELISA]). Samples from 60 women with three or more pregnancies with a negative ELISA were further tested using microbead-flow assays (LABScreen mixed, panel-reactive antibodies [PRA], and single antigen). RESULTS: Anti-HLA Class I and/or Class II were detected by ELISA in 26.7% (80/300) of all women and in 37.0% (37/100) of women with three or more pregnancies. The LABScreen assays detected additional anti-HLA specificities (44 Class I and 17 Class II) in 28.3% (17/60) of ELISA-negative donors with three or more pregnancies. HLA antibodies were detected in 8.3% (5/60), 18.3% (11/60), and 21.7% (13/60) of ELISA-negative women by LABScreen mixed, PRA, or single antigen, respectively. CONCLUSION: Our data showed that the microbead-flow detected more HLA antibodies than ELISA, but the clinical significance of these antibodies is currently unknown. Detecting anti-HLA is useful for donor management and could contribute to the decision to definitively defer blood donors involved in TRALI incidents. However, further studies are necessary to better determinate the relative risk of TRALI induced by anti-HLA detected only by techniques with higher sensitivity rate.
Assuntos
Autoanticorpos/sangue , Doadores de Sangue/estatística & dados numéricos , Antígenos HLA/sangue , Antígenos HLA/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Antígenos HLA-D/sangue , Antígenos HLA-D/imunologia , Antígenos de Histocompatibilidade Classe I/sangue , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Paridade , Gravidez , Sensibilidade e EspecificidadeRESUMO
In populations such as Northern Europeans in which the HLA-DR4 subtypes DW14 and Dw4 show strong association with rheumatoid arthritis (RA), these alleles and the double allelic dose of the shared epitope are considered severity markers. The clinical expression of RA varies in different populations, which may be determined by variation in the prevalence of these markers. In the present study we analyzed the expression of RA in 112 consecutive Chilean patients and its relation to the prevalence of genetic factors, prompted by our previous observation that DR4 is weakly associated to RA in this population. Mean age was 50 +/- 14 years; 90% were seropositive and 87% were female, with a disease duration of 10 +/- 8 years. Extra-articular manifestations were found in 38% of patients, rheumatoid nodules in 27%, vasculitis in 8%, and Sjogren's syndrome in 29%. Functional capacity (ACR, 1991) I or II: 82%.15% of patients stopped working. Hand radiographs scored according to Steinbrocker in 89 patients: I, 21%; II, 15%; III, 43%; IV, 21%. In this series, patients with less formal education seemed to have more benign arthritis. In 97 controls and in 65 (56%) RA patients the presence of DRB1 alleles corresponding to DR1 and DR4 serotypes, to DR4-Dw subtypes, and homozygocity, were determined by polymerase chain reaction followed by specific oligonucleotide hybridization. The shared epitope was present in 53% of RA patients and in 30% of controls (P = .0048, odds ratio [OR] = 2.64). A double allelic dose of the epitope was present in 15% of RA patients compared with 4% of controls (P = .026, OR = 4.23). In a subgroup of 31 erosive RA patients we did not find a significant association of disease severity with the shared epitope in a single or double allelic dose. None of the DR4 subtypes that associate with RA in other populations was found significantly more prevalent in our patients. The severity of RA in our study compared with published series was intermediate between British patients with severe RA and Greek patients with milder disease. This may be due to the high prevalence of Dwl3*0403 in our population.
Assuntos
Artrite Reumatoide/epidemiologia , Artrite Reumatoide/imunologia , Adulto , Fatores Etários , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Chile/epidemiologia , Escolaridade , Feminino , Antígenos HLA-D/sangue , Antígeno HLA-DR4/sangue , Teste de Histocompatibilidade , Homozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Prognóstico , Fatores Sexuais , Fatores de Tempo , TrabalhoRESUMO
The prevalence of class I and class II HLA antigen was analyzed in 14 patients (12 males, two females) with Whipple's disease, diagnosed an average of 9.7 yr (range 6 months to 25 yr) before the typing. They were compared with 174 healthy control subjects of the same geographic area in Argentina. Class I antigens (locus A, B, C) were studied by lymphocytotoxic test, and class II antigens (locus DR, DQ) were detected by the double immunofluorescence technique. HLA-B27 was positive in one patient (7.7%) and in 4% of the control population. No significant association was found with the antigens tested. We observed no difference in the clinical picture or in the frequency of arthralgias, compared with those reported in the literature. Our data suggest that there is no conclusive proof of an association between HLA-B27 and Whipple's disease.