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 metabolites (NOX) in patients with severe ulcerative colitis and to assess whether these concentrations predict clinical outcome.

PATIENTS

Twenty-six patients (16 men and 10 women, mean age 46 years) with severe ulcerative colitis requiring hospitalization for parenteral steroid therapy. Thirteen patients had a complete clinical response and symptoms resolved after 5 days of parenteral steroid administration; 13 made an incomplete recovery and needed further treatment (six cyclosporin, seven colectomy).

METHODS

Serum concentrations of NOX and C-reactive protein (CRP) were measured daily for 3 days in all patients and as clinically indicated thereafter. The normal range for NOX was established by measuring the concentration in 25 healthy controls.

RESULTS

Mean serum NOX and CRP concentrations were significantly elevated in both the patients with a complete and those with an incomplete response compared with controls (P < 0.001) on day 1 and fell during the first 3 days of therapy. On day 3, mean serum concentrations of NOX and CRP were lower in the patients with a complete response, but only the difference in CRP attained statistical significance (P = 0.02). There was no correlation between NOX and CRP concentrations.

CONCLUSIONS

In the majority of patients with severe ulcerative colitis, circulating concentrations of NOX are increased at presentation and fall promptly during parenteral steroid therapy, irrespective of clinical outcome. However, in a small number of patients NOX concentrations do not fall during steroid treatment and such patients will probably require additional medical therapy or surgery.