Genetic variation in proinflammatory and anti-inflammatory cytokine production in multiple organ dysfunction syndrome

The objectives of this study were to examine the prevalence of genetic variation for cytokine production (tumor necrosis factor [TNF]-alpha, interleukin-10, transforming growth factor-beta1) in patients with multiple organ dysfunction syndrome, to measure circulating cytokine levels and relate these to genotype, and to identify the relationship between genetic variation and outcome.

Prospective analysis.

Intensive care unit of a university teaching hospital.

Eighty-eight critically ill patients with multiple organ dysfunction syndrome.

The frequency of the different interleukin-10 genotypes (corresponding to high, intermediate, and low interleukin-10 production ) were significantly different between controls and multiple organ dysfunction syndrome patients. High interleukin-10 producers were under-represented in the multiple organ dysfunction syndrome group: This genotype occurred in 30% of controls but in only 6% of patients ( <.001). There was no relationship between interleukin-10 genotype and mortality. The frequency of TNF-alpha genotypes was also significantly different between patients and controls. Intermediate TNF-alpha producers were under-represented (5.7% vs. 23%) and high TNF-alpha producers over-represented (35.2% vs. 16%) in the patient group (p <.001). TNF-alpha genotype was not related to mortality. The distribution of TNF-beta genotypes (homozygous B1, homozygous B2, and heterozygotes) was also different between controls and patients (p =.008). The B2/B2 genotype (associated with high TNF-alpha production) tended to occur less frequently in the intensive care unit population (31% vs. 50%) and was associated with a higher mortality rate than either the B1/B1 or B1/B2 genotypes (48% vs. 11% and 33% respectively, p=.115). The combination of proinflammatory (TNF-alpha/TNF-beta) and anti-inflammatory (interleukin-10/transforming growth factor-beta1) cytokine genotypes was associated with prolonged patient survival time. Patients predisposed to produce a balanced cytokine response (e.g., intermediate interleukin-10/TNF-alpha producers) demonstrated the longest survival times, although overall mortality was no different.

A genetic predisposition to high interleukin-10 production or intermediate TNF-alpha production may be protective of admission to the intensive care unit, although once admitted, any protection provided by these genotypes seems to be lost. TNF-beta genotype conferred no advantage to patients with multiple organ dysfunction syndrome, the TNFB2 allele being associated with increased mortality. The combination of proinflammatory and anti-inflammatory cytokine genotypes supports the idea that a balanced cytokine response is favorable and was associated with prolonged patient survival time.