Association of variable number tandem repeats polymorphism in the IL-4 gene with end-stage renal disease in children

Interleukin-1 receptor antagonist (IL-1RA) and interleukin-4 (IL-4) variable number of tandem repeat polymorphisms in schizophrenia and bipolar disorder: an association study in Turkish population

Background

Pro-inflammatory/anti-inflammatory cytokine imbalance in cerebrospinal fluid or plasma of schizophrenia (SCZ) and bipolar disorder (BD) patients has been documented over the last decade. We aim to examine the interleukin-1 receptor antagonist (IL-1RA) and IL-4 variable number of tandem repeat (VNTR) polymorphisms in SCZ and BD patients by comparing them with healthy controls.

Methods

Two hundred and thirty-four unrelated patients (127 patients with SCZ, 107 patients with BD) and 204 healthy controls were included. The Structured Clinical Interview for DSM-IV Axis I Disorders was used to confirm the diagnosis. In addition, the polymerase chain reaction technique was used to investigate IL-1RA and IL-4 VNTR polymorphisms.

Results

Our results showed that the distributions of IL-1RA and IL-4 genotype and the allele frequencies of SCZ or BD patients were not significantly different from the healthy control group. IL-1RA allele 2 homozygous genotype and IL-1RA allele 2 frequencies were non-significantly higher among SCZ patients than in controls.

Conclusions

Our study indicates that the IL-1RA and IL-4 VNTR polymorphisms are not considered risk factors for developing SCZ and BD among Turkish patients.

Interleukin-4 gene intron 3 VNTR polymorphism in adult acute myeloid leukemia

Background

The proliferation of acute myeloid leukemia (AML) blast into the bone marrow microenvironment is controlled by cytokines. Interleukin-4 (IL-4) has recently been discovered to suppress the development and persistence of AML cells selectively. Intron three of the Interleukin-4 (IL-4) gene contains a 70-bp minisatellite region polymorphism that may influence gene transcriptional activity and subsequently affect the production level of IL4. We investigated the IL-4 gene intron three variable number tandem repeat (VNTR) polymorphism as a molecular marker in AML associated with clinical and laboratory variables and a prognostic factor for therapeutic response and disease outcome.

Results

IL-4 gene intron three minisatellite regions polymorphism was assessed in 60 adult AML patients and 60 healthy controls, comparable concerning age and gender, using polymerase chain reaction. Three study marker genotypes were detected in AML patients; P1/P1 (3%), P1/P2 (40%), and P2/P2 (56.7%). The frequency of P2 alleles was significantly more in AML patients than in healthy controls (76.7% versus 25%; P < 0.001). Compared to the heterozygous group and P1/P1 carriers, AML patients with the homozygous P2/P2 genotype had a higher total leucocytic count and increased blast percentages in bone marrow or peripheral blood, besides a lower platelet count. P2P2 genotype was also significantly associated with poor therapeutic response, higher susceptibility to disease recurrence and shorter overall survival and disease-free survival.

Conclusion

The IL-4 intron 3 VNTR polymorphism could be included in the molecular risk stratification of AML to predict poor disease. This information can be utilized in incorporating biological therapy into the present therapeutic protocols to enhance chemotherapy regimens’ current low response rates.

Polymorphisms of interleukin 4 and interleukin 4 receptor genes and bronchial asthma risk among Egyptian children

BACKGROUND

Interleukin 4 (IL4) is a key cytokine that regulates the inflammatory cascade in bronchial asthma. We investigated the association between the IL4 and IL4R polymorphisms and the susceptibility for bronchial asthma among Egyptian children.

METHODS

IL4 VNTR and IL4R c.1902 A>G p.(Q576R) polymorphisms were investigated among 100 children with bronchial asthma and 100 healthy controls using PCR method. Serum levels of IL4 and immunoglobulin E (IgE) were assessed by ELISA.

RESULTS

The frequencies of (A1A2 + A2A2) genotypes and A2-allele of the IL4 VNTR variant were significantly higher among asthmatic patients than controls (p = 0.01, OR = 2.34, 95% CI = 1.24-4.44; p = 0.01, OR = 2.27, 95% CI = 1.29-3.99, respectively). The frequencies of (AG + GG) genotypes and G-allele of the IL4R (A1902G) variant were significantly higher among asthmatic patients than controls (p = 0.003, OR = 2.52, 95% CI = 1.39-4.58; p = 0.002, OR = 2.25, 95% CI = 1.35-3.76, respectively). There was a significant association between (A1A2 + A2A2) genotypes of the IL4 VNTR variant and high serum IL4 level among asthmatic patients (p < 0.001). The (AG + GG) genotypes of the IL4R (A1902G) variant were significantly associated with exposure to triggers, atopic dermatitis and higher serum IgE level in asthmatic patients (p = 0.02, 0.04 and 0.01, respectively).

CONCLUSION

IL4 VNTR and IL4R (A1902G) polymorphisms could be associated with higher risks of bronchial asthma among Egyptian children.