Medical therapy of specific clinical presentations

Cytomegalovirus infection in steroid-refractory ulcerative colitis: a case-control study

Cytomegalovirus (CMV) infection is reported to be a cause of steroid-refractory ulcerative colitis (UC), but the strength of this association has not been tested in a case control study. Controlled studies have also not been performed to determine the sensitivity of available immunohistochemical techniques to detect CMV in this setting. The pathology database at Stanford Hospital was searched for UC patients with a diagnosis of "severe colitis" between the years 1992 and 2002 and medical records were reviewed. Forty patients were identified with refractory UC, defined as poor response to highdose systemic steroids for >2 weeks. Another group of 40 patients with severe, but nonrefractory, UC was case-matched for age and year of biopsy. A series of 40 patients who underwent colectomy for reasons other than inflammatory bowel disease with representative sections of "normal" colon were selected as noncolitis controls. CMV inclusions were detected on hematoxylin and eosin (H&E) in 2 of 40 patients with refractory UC, but not in other patients. Immunohistochemistry (IHC) detected CMV in 10 of 40 (25%) patients with refractory UC and 1 of 40 (2.5%) patients with nonrefractory UC (P = 0.007). The CMV-positive cases initially identified on IHC but not on H&E were re-reviewed for viral inclusions on H&E: 3 had rare, but typical, inclusions; 3 had atypical inclusions; and 3 had no inclusions. CMV was not detected by H&E or IHC in 40 noncolitis controls. Of 10 steroid-refractory UC patients with CMV detected, 7 were refractory to cyclosporin or 6-mercaptopurine/azathioprine (70%) and 6 had undergone proctocolectomy (60%) prior to detection of the CMV. Two patients with recognized CMV infection were treated with gancyclovir, improved, and were able to taper off steroids and avoid proctocolectomy. This study provides evidence that unrecognized and therefore untreated CMV infection is significantly associated with steroid-refractory UC. Moreover, IHC is more sensitive than H&E for detection of CMV and should be considered as part of the routine evaluation of steroid-refractory UC patients, before proceeding with other medical or surgical therapy that may be unnecessary once the CMV is treated.

Mercaptopurine metabolite results in clinical gastroenterology practice

BACKGROUND

Azathioprine (AZA) and its active metabolite mercaptopurine (MP) are frequently used in the management of inflammatory bowel disease. Measurement of the AZA/MP metabolites, thioguanine (TG) and methylmercaptopurine (MMP), has been suggested as a means to optimize therapy with AZA/MP in inflammatory bowel disease.

AIM

To evaluate the results of initial AZA/MP metabolite panels sent by gastroenterologists during the first year of its widespread availability.

METHODS

Initial AZA/MP metabolite panels sent by gastroenterologists to a single laboratory were reviewed and the metabolite panels were interpreted.

RESULTS

Initial metabolite levels were reviewed for 9187 patients. Noncompliance was detected in 263 patients (3%) and under-dosing in 4260 patients (46%). 534 patients (6%) had levels that were consistent with preferential metabolism via the TPMT pathway. The therapeutic goal was achieved in 2444 patients (27%) and an additional 552 patients (6%) had appropriate TG levels but potential hepatotoxicity. 936 patients (10%) had potential TPMT deficiency, and 58 patients (1%) had potential TPMT absence and were at risk for leukopenia. 140 patients (2%) had too high a dose.

CONCLUSIONS

Measurement of AZA/MP metabolites can be used by practising gastroenterologists to identify potential reasons for nonresponse to AZA or MP, and to identify patients at risk for certain drug-related toxicities.

Medical treatment of Crohn's disease

Crohn's disease is not medically (and is rarely surgically) curable. Patients do, however, live a normal life span. The goal of therapy is to optimize the quality of life, minimize disease activity and disease-related complications, and avoid therapeutic toxicity.

Pharmacokinetics of cyclosporin microemulsion in patients with inflammatory bowel disease

OBJECTIVE

To obtain a pharmacokinetic profile of cyclosporin microemulsion formulation in patients with inflammatory bowel disease.

PATIENTS AND PARTICIPANTS

58 consecutive patients (19 women and 39 men), aged 16 to 64 years (mean age 38 years), with a diagnosis of ulcerative colitis (29 patients) or Crohn's disease (29 patients).

METHODS

Patients were treated with oral doses of cyclosporin microemulsion ranging from 200 to 400 mg daily. Blood samples were collected after 7 days of treatment; blood was drawn at 0, 0.5, 1, 2, 3, 5, 7 and 12 hours after the morning dose. In 23 patients out of 29 with ulcerative colitis and 23 out of 29 with Crohn's disease, these profiles were repeated immediately before hospital discharge, which took place an average of 18 days after admission. Blood specimens were assayed for cyclosporin immunoreactivity on the day of blood withdrawal by a radioimmunoassay technique.

MAIN OUTCOME MEASURES AND RESULTS

In the range of doses employed, the average peak plasma drug concentration (Cmax) and area under the concentration-time curve to 12 hours tended to increase linearly with the dose (from 782.35 to 1,607.98 microg/L and from 3,612 to 7,221 microg x h/L for doses of 200 mg and 400 mg, respectively), whereas the time to Cmax (tmax) and elimination half-life (t 1/2beta) ranged between 78 and 95.2 min and 85.5 and 162 min, respectively, and did not appear to change with the dose. After dose-normalisation by transformation of data into percentage increase over baseline (trough) concentration for each patient, single kinetic parameters for the whole study population (n = 58) could be calculated (Cmax 620% vs baseline. tmax 86.5 min, t 1/2 115 min). Comparison between patients with Crohn's disease and ulcerative colitis showed that the latter had higher Cmax values (702% compared with 543% vs baseline, p < 0.05) whereas tmax and t 1/2beta values overlapped.

CONCLUSIONS

The pharmacokinetic parameters of cyclosporin microemulsion in patients with inflammatory bowel disease are broadly similar to those previously measured in healthy volunteers and in other disorders requiring cyclosporin treatment.

Inflammatory bowel disease in the elderly

Approximately 15% of all patients with IBD first develop symptoms after age 65. As the number of elderly in the population continues to grow, clinicians should expect to see a greater number of elderly IBD patients. In general, the presenting features of IBD are similar to those encountered in younger patients, but the broad differential diagnosis of colitis in the elderly can make definitive diagnosis more challenging. Although most therapies for IBD have not been studied specifically in the elderly, as a general rule, medical and surgical treatment options are the same regardless of age. Osteoporosis, a condition generally associated with aging, should be managed aggressively in patients with IBD because many older persons already have a substantial baseline risk for accelerated bone loss.