Association of IL-10 polymorphism with severity of illness in community acquired pneumonia

• Published in: Thorax 2003-02, Vol.58 (2), p.154-156
• Main Authors: Gallagher, P M, Lowe, G, Fitzgerald, T, Bella, A, Greene, C M, McElvaney, N G, O’Neill, S J
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Bacterial diseases; Bacterial diseases of the respiratory system; Bacterial pneumonia; Biological and medical sciences; Blood; Case-Control Studies; Chromosomes; Chronic obstructive pulmonary disease; community acquired pneumonia; Community-Acquired Infections - genetics; Cytokines; Effectiveness; Genetic aspects; Human bacterial diseases; Humans; IL-10 polymorphism; Illnesses; Infectious diseases; Interleukin-10; Interleukin-10 - genetics; Interleukin-6 - genetics; Medical sciences; Physiological aspects; Pneumonia; Pneumonia - genetics; Polymerase Chain Reaction - methods; Polymorphism; Polymorphism, Genetic; Polymorphism, Restriction Fragment Length; Pulmonary Disease, Chronic Obstructive - complications; Regression analysis; Sepsis; Short Paper; Smoking - adverse effects; systemic inflammatory response syndrome; Systemic Inflammatory Response Syndrome - etiology; Tumor Necrosis Factor-alpha - genetics; Tumor necrosis factor-TNF
• ISSN: 0040-6376; 1468-3296
• DOI: 10.1136/thorax.58.2.154

Background: The influence of genetic polymorphisms of interleukin (IL)-10, tumour necrosis factor (TNF)-α, and IL-6 gene promoters on severity of systemic inflammatory response syndrome (SIRS) associated with community acquired pneumonia (CAP) was studied. Methods: Using PCR-RFLP analysis we analysed a −1082G/A single nucleotide polymorphism (SNP) of the anti-inflammatory IL-10 gene, a −308G/A SNP of the pro-inflammatory TNF-α gene and a −174G/C SNP of the IL-6 gene. Illness severity was stratified according to SIRS score, calculated by presence of up to four physiological indices: temperature, white blood cell count, heart rate and respiratory rate (non-SIRS, SIRS 2, SIRS 3, and SIRS 4). Results: A statistically significant stepwise increase in frequency of the IL-10 G allele, associated with higher expression of the gene, was observed in patients with increasing severity of illness from non-SIRS (n=19) to SIRS 2 (n=17), SIRS 3 (n=33) and SIRS 4 (n=24). This was primarily due to a higher frequency of the GG genotype with increasing severity from non-SIRS through to SIRS 4. IL-10 G allele frequency was also increased in patients who died as a result of CAP (n=11) compared with CAP survivors (n=82) (p=0.01). No association was seen between the TNF-α −308G/A and IL-6 −174G/C SNPs and disease. Additionally, no interaction between all three SNP genotypes and disease severity was observed. Conclusions: A polymorphism affecting IL-10 expression may influence the severity of illness in patients with CAP.