Bacteremia in solid organ transplant recipients as compared to immunocompetent patients: Acute phase cytokines and outcomes in a prospective,matched cohort study

We undertook a prospective, matched cohort study of patients with Staphylococcus aureus bacteremia (SAB) and gram-negative bacteremia (GNB) to compare the characteristics, outcomes, and chemokine and cytokine response in transplant recipients to immunocompetent, nontransplant recipients. Fifty-five transplant recipients (GNB n = 29; SAB n = 26) and 225 nontransplant recipients (GNB n = 114; SAB n = 111) were included for clinical analysis. Transplant GNB had a significantly lower incidence of septic shock than nontransplant GNB (10.3% vs 30.7%, p = .03). Thirty-day mortality did not differ significantly between transplant and nontransplant recipients with GNB (10.3% vs 15.8%, p = .57) or SAB (0.0% vs 11.7%, p = .13). Next, transplant patients were matched 1:1 with nontransplant patients for the chemokine and cytokine analysis. Five cytokines and chemokines were significantly lower in transplant GNB vs nontransplant GNB: IL-2 (median IQR]: 7.1 pg/ml 7.1, 7.1] vs 32.6 pg/ml 7.1, 88.0]; p = .001), MIP-1β (30.7 pg/ml 30.7, 30.7] vs 243.3 pg/ml 30.7, 344.4]; p = .001), IL-8 (32.0 pg/ml 5.6, 53.1] vs 59.1 pg/ml 39.2, 119.4]; p = .003), IL-15 (12.0 pg/ml 12.0, 12.0] vs 12.0 pg/ml 12.0, 126.7]; p = .03), and IFN-α (5.1 pg/mL 5.1, 5.1] vs 5.1 pg/ml 5.1, 26.3]; p = .04). Regulated upon Activation, Normal T Cell Expressed and Secreted (RANTES) was higher in transplant SAB vs nontransplant SAB (mean SD]: 750.2 pg/ml 194.6] vs 656.5 pg/ml 147.6]; p = .046).