Georgina Márquez

HLA-B27 subtypes determination in patients with ankylosing spondylitis from Zulia, Venezuela

To perform an investigation regarding the distribution of the human leukocyte antigen (HLA)-B27 subtypes in the Zulian population with ankylosing spondylitis (AS), 48 unrelated Mestizos, HLA-B27 positive by serology, were studied using the polymerase chain reaction-specific sequence oligonucleotides probe (PCR-SSOP) and specific sequence primers (SSP) to analyze the polymorphism in exons 2 and 3 of the HLA-B27 gene. Only two of eight HLA-B27 subtypes studied (B*2701-B*2708) were found. The distribution of these alleles in the population of patients was: B*2705, 68.8%, and B*2702, 31.2%. B*2705 subtype showed significant association with patients being male. In the healthy controls, the most common subtype was B*2708. These results were compared with frequencies reported in other Mestizo and Spanish populations and showed significant differences, such as a high frequency of B*2702. Such results show that HLA*B2705 and HLA*B2702 are the subtypes most frequently associated with AS in our Mestizo population and suggest a possible protector role for HLA*B2708, which was found only in the healthy population.

Patrones diferenciales de distribución de los alelos y genotipos HLA-DPA1* en asociación con leucemias linfoides agudas y leucemias mieloides crónicas en pacientes del estado Zulia, Venezuela

Resumen Poco se sabe aun de la relevancia del polimorfismo y la funcion del HLA-DP. La leucemia linfoide aguda (LLA) es el cancer mas frecuente en ninos y adolescentes en la poblacion zuliana de Venezuela. La leucemia mieloide cronica (LMC) afecta igualmente a ninos, jovenes y adultos. Varios estudios epidemiologicos revelan la presencia de ciertos factores asociados con la susceptibilidad. El locus HLA-DPA1*, alelos HLA-DPA1*01, *02, *03 y *04, se estudiaron utilizando los estuches PCR Olerup SSPTM (Genovision), en una poblacion de 48 pacientes con LLA, 48 con LMC y 48 controles sanos provenientes del Banco de Sangre del Estado Zulia, Venezuela, mestizos no relacionados. El analisis estadistico de las frecuencias se determino por recuento directo; la comparacion de las frecuencias alelicas se realizo con la prueba de χ2 corregida por Yates y los valores de p 2,5 se consideraron asociaciones positivas y los