ARE SERUM CONCENTRATIONS OF NITRIC-OXIDE METABOLITES USEFUL FOR PREDICTING THE CLINICAL OUTCOME OF SEVERE ULCERATIVE-COLITIS

Objective: To determine serum concentrations of nitric oxide metabolit es (NO(x)) in patients with severe ulcerative colitis and to assess wh ether these concentrations predict clinical outcome. Patients: Twenty- six patients (16 men and 10 women, mean age 46 years) with severe ulce rative colitis requiring hospitalization for parenteral steroid therap y. Thirteen patients had a complete clinical response and symptoms res olved after 5 days of parenteral steroid administration; 13 made an in complete recovery and needed further treatment (six cyclosporin, seven colectomy). Methods: Serum concentrations of NO(x) and C-reactive pro tein (CRP) were measured daily for 3 days in all patients and as clini cally indicated thereafter. The normal range for NO(x) was established by measuring the concentration in 25 healthy controls. Results: Mean serum NO(x) and CRP concentrations were significantly elevated in both the patients with a complete and those with an incomplete response co mpared with controls (P < 0.001) on day 1 and fell during the first 3 days of therapy. On day 3, mean serum concentrations of NO(x) and CRP were lower in the patients with a complete response, but only the diff erence in CRP attained statistical significance (P = 0.02). There was no correlation between NO(x) and CRP concentrations. Conclusions: In t he majority of patients with severe ulcerative colitis, circulating co ncentrations of NO(x) are increased at presentation and fall promptly during parenteral steroid therapy, irrespective of clinical outcome. H owever, in a small number of patients NO(x) concentrations do not fall during steroid treatment and such patients will probably require addi tional medical therapy or surgery.