Serum Cytomegalovirus Polymerase Chain Reaction Test Is a Valuable Negative Predictor of Infection in Acute Severe Ulcerative Colitis.

BACKGROUND

Diagnosis of cytomegalovirus (CMV) colitis in the setting of severe ulcerative colitis (UC) remains a clinical challenge. This study aimed to determine the utility of serum CMV polymerase chain reaction (PCR) as a non-invasive test for the diagnosis of CMV superinfection in patients hospitalized with UC.

METHODS

This retrospective study included consecutive admitted patients with UC who had serum testing for CMV completed as part of standard hospital procedure and CMV colitis diagnosed by expert pathologists.

RESULTS

Two hundred and six patients with UC were included; 13 patients (6%) had histologically confirmed CMV colitis. Eleven of 13 patients with CMV colitis (84%) and 3 of 193 (1.5%) patients without CMV colitis had a positive serum PCR test (p < 0.0001). ROC analysis showed that a CMV PCR level of 259 IU/mL had a sensitivity and specificity of 77% and 99%, respectively, for diagnosis of CMV colitis with an AUC of 0.9 (p < 0.0001). Serum CMV PCR level significantly correlated to the number of inclusion bodies on biopsy specimens with data available (n = 8) (r = 0.8, p = 0.02). CMV positivity did not predict the need for salvage therapy, admission or 1-year colectomy rates.

CONCLUSION

Serum CMV PCR has an excellent negative predictive value and demonstrates a strong correlation with CMV positivity on histology. This work supports a rationale for serum CMV PCR testing on admission to assess the risk of CMV colitis in patients with severe UC.