Associação entre HLA e leucemia em uma população brasileira de etnia mista / Association between HLA and leukemia in a mixed Brazilian population

OBJETIVOS: O objetivo deste estudo foi investigar a freqüência de antígenos HLA Classe I e de alelos HLA Classe II em 164 pacientes com vários tipos de leucemias: 35 pacientes com LLA (leucemia linfóide aguda), 50 com LMA (leucemia mielóide aguda) e 78 com LMC (leucemia mielóide crônica). MÉTODOS: A tipagem HLA Classe I foi realizada por microlinfocitotoxicidade e a de Classe II por PCR-SSP (polymerase chain reaction - sequence specific of primers), ambas da One Lambda (Canoga Park, CA, US). RESULTADOS: Em pacientes com LLA, as freqüências das variantes HLA-B45 e HLA-B56 foram maiores (P = 0,02; OR = 3,13; 95 por centoIC = 0,94-10,44; P = 0,03; OR = 3,61; 95 por centoIC = 0,47-27,64, respectivamente), quando comparadas com controles. Nos pacientes com LMA, a freqüência de HLA-B7 (P = 0,01; OR = 2,41; 95 por centoIC = 1,25-4,67) foi maior que em controles. A presença de HLA-B45 (P= 0,01; OR = 3,29; 95 por centoIC = 1,46-7,40) e de HLA-DRB1*04 (P = 0,002; OR = 2,17; 95 por centoIC = 1,36-3,46) e HLA-DRB1*08 (P = 0,004; OR = 2,36; 95 por centoIC = 1,34-4,16) foi associada ao maior risco de desenvolver LMC. CONCLUSÃO: Nossos resultados sugerem que variantes HLA conferem susceptibilidade a algumas formas de leucemia e podem prover novas ferramentas para a investigação da genética e etiologia desta doença.

OBJECTIVE: The main purpose of this study was to investigate the class I HLA antigens and class II HLA allele frequencies in 164 patients with leukemia: 35 patients with ALL (acute lymphoid leukemia), 50 with AML (acute myeloid leukemia) and 78 with CML (chronic myeloid leukemia). METHODS: The genotyping of class I HLA was performed by microlymphocytotoxicity and of class II by PCR-SSP (polymerase chain reaction - sequence specific of primers) (One Lambda, Canoga Park, CA, USA). RESULTS: In patients with LLA, frequencies of HLA-B45 and HLA-B56 were higher (P = 0.02; OR = 3.13; 95 percentIC = 0.94-10.44; P = 0.03; OR = 3.61; 95 percentIC = 0.47-27.64, respectively), than in controls. In patients with AML, the frequency of HLA-B7 (P = 0.01; OR = 2.41; 95 percentIC = 1.25-4.67) was higher than in controls. The presence of HLA-B45 (P= 0.01; OR = 3.29; 95 percentIC = 1.46-7.40), HLA-DRB1*04 (P = 0.002; OR = 2.17; 95 percentIC = 1.36-3.46) and HLA-DRB1*08 (P = 0.004; OR = 2.36; 95 percentIC = 1.34-4.16) was associated to increased risk of CML developing. CONCLUSION: Our results suggest that variants of HLA confer susceptibility to the same forms of leukemia, and could provide new tools for the investigation of genetics and etiology of this disease.

Addition of exogenous cytokines in mixed lymphocyte culture for selecting related donors for bone marrow transplantation

CONTEXT: Mixed lymphocyte culturing has led to conflicting opinions regarding the selection of donors for bone marrow transplantation. The association between a positive mixed lymphocyte culture and the development of graft-versus-host disease (GVHD) is unclear. The use of exogenous cytokines in mixed lymphocyte cultures could be an alternative for increasing the sensitivity of culture tests. OBJECTIVE: To increase the sensitivity of mixed lymphocyte cultures between donor and recipient human leukocyte antigen (HLA) identical siblings, using exogenous cytokines, in order to predict post-transplantation GVHD and/or rejection. TYPE OF STUDY: Prospective study. SETTING: Bone Marrow Transplantation Unit, Universidade Estadual de Campinas. PARTICIPANTS: Seventeen patients with hematological malignancies and their respective donors selected for bone marrow transplantation procedures. PROCEDURES: Standard and modified mixed lymphocyte culturing by cytokine supplementation was carried out using donor and recipient cells typed for HLA. MAIN MEASUREMENTS: Autologous and allogenic responses in mixed lymphocyte cultures after the addition of IL-4 or IL-2. RESULTS: In comparison with the standard method, average responses in the modified mixed lymphocyte cultures increased by a factor of 2.0 using IL-4 (p < 0.001) and 6.4 using IL-2 (p < 0.001), for autologous donor culture responses. For donor-versus-recipient culture responses, the increase was by a factor of 1.9 using IL-4 (p < 0.001) and 4.1 using IL-2 (p < 0.001). For donor-versus-unrelated culture responses, no significant increase was observed using IL-4, and a mean response inhibition of 20 percent was observed using IL-2 (p < 0.001). Neither of the cytokines produced a significant difference in the unrelated control versus recipient cell responses. CONCLUSION: IL-4 supplementation was the best for increasing the mixed lymphocyte culture sensitivity. However, IL-4 also increased autologous responses, albeit less intensively than IL-2. Thus, with this loss of specificity we believe that it is not worth modifying the traditional mixed lymphocyte culture method, even with IL-4 addition

Incidência de pacientes hipersensibilizados em lista de espera contra doador cadáver / Incidence of hypersencitized patients in waiting lists for cadaver donois

Cento e vinte pacientes em programa crônico de diálise (38,8 = 17,3 meses) a espera de transplante renal em lista de doador cadáver foram analisados quanto ao grau de infocitotoxicidade contra um painel selecionado de 22 células HLA (A, B) tipadas e fixas. Os pacientes foram distribuídos em três grupos quanto ao nível de sensibilizaçäo (0-9,9%, 10-49,9% e acima de 50%). O número de pacientes em cada nível foi de 61 (49%), 33 (26%) respectivamente. O sexo femenino significativamente superior no grupo de hipersensibilidados (> 50%) e o sexo masculino no de näo sensibilizados (0-9,9%). As gestaçöes prévias parecem ter contribuido para este caráter de hiperreatividade. Näo ocorreu um percentual crescente de hipersensibilizados a medida que se prolongava o tempo em diálise, estando o grupo hipersensibilizados já precocemente definido nos primeiros seis meses de diálise. No grupo de pacientes com mais de um painel, o grau de sensibilizaçäo permaneceu estável em 65% e nos restantesfoi observado uma tendência a elevaçäo e, 17,4%, a queda em 5,8*, e um comportamento errático em 11,8%