Association between the genetic polymorphism of interleukin-1ß (3953 T/C) and symptomatic lumbar herniated disc

Abstract

Objective

To evaluate the association between the presence of the genotype of certain genetic polymorphisms (GP) of the cytokine and oxide nitric synthase (NOS) and the development of lumbar herniated disc (LHD).

Materials and methods

We reviewed 179 patients in a retrospective case-control study. The case group was made up of 50 patients with confirmed lumbar herniated disc diagnosed by Magnetic Resonance Imaging (MRI). The control group was made up of patients admitted for hip and knee prosthetic surgery who did not have or had not had any symptoms consistent with LHD. Blood was drawn from all of the study participants. The genotypes of the GP were obtained of the cytokines to be studied: Interleukin-1 [IL-1α [−889 C/T), IL-1ß [+3953 T/C)], Tumor Necrosis Factor-α [TNF-α[−308 G/A] and [−238G/A]).

Results

The CC genotype and C allele frequency of the IL-1ß PG (+3953T/C) polymorphism were significantly more frequent in patients with LDH compared to the controls. On the contrary, the control group patients carried eNos GPs (−768 T/C) and iNOS22 G/A polymorphisms more frequently than the LHD group, this difference being statistically different for both polymorphisms.

Conclusions

We found that individuals who were carriers of the CC genotype of the IL-1ß (+3953T/C) polymorphism showed higher susceptibility to suffer lumbar disc herniation. Furthermore, being a carrier of ENOS (−786 T/C) and iNOS (22 G/A) polymorphisms suggests that this could behave as a protection factor against disc herniation.

Resumen

Objetivo

Evaluar la asociación entre la presencia en el genotipo de determinados polimorfismos genéticos (PG) de las citocinas y del óxido nítrico sintasa (NOS) y el desarrollo de la hernia discal lumbar (HDL) sintomática.

Material y método

Se revisaron 179 pacientes en un estudio retrospectivo de casos y controles. El grupo de casos estaba formado por 50 pacientes con HDL confirmada mediante resonancia magnética. El grupo control lo componían pacientes ingresados para cirugía protésica de la cadera o de la rodilla que no presentaban ni habían presentado nunca clínica compatible con HDL. Se realizó una extracción de sangre a todos los participantes del estudio. Se genotiparon los PG de las citocinas que pretendíamos estudiar: interleucina (IL)-1 (IL-1α [−889 C/T] e IL-1ß [+3953 T/C]) y factor de necrosis tumoral-α (TNF-α [−308 G/A] y TNF-α [−238 G/A]).

Resultados

El genotipo CC y la frecuencia del alelo C del PG IL-1ß (+3953 T/C) fueron significativamente mayores en el grupo de pacientes con HDL respecto a la población control. Por el contrario, los pacientes del grupo control portaban los PG de NOS endotelial (−768 T/C) y de NOS inducible 22 G/A con mayor frecuencia que el grupo de pacientes con HDL, esta diferencia es estadísticamente significativa para ambos polimorfismos.

Conclusiones

Encontramos que ser portador del alelo C del PG IL-1ß (+3953 T/C) puede ser un factor de predisposición para desarrollar una HDL. Por otro lado, ser portador del PG NOS endotelial (−768 T/C) y del NOS inducible 22 G/A parece comportarse como un factor protector frente al desarrollo de esta enfermedad.