Late-onset colitis after cord blood transplantation is consistent with graft-versus-host disease: results of a blinded histopathological review.

Cord colitis syndrome after umbilical cord blood transplantation (UCBT) involves late-onset diarrhea, absence of infection or GVHD, chronic active colitis, and granulomatous inflammation that responds to antibiotics. We tested the hypothesis that Seattle recipients of UCBT had late-occurring colitis distinct from GVHD and colitis in other allograft recipients. We conducted a blinded histological review of 153 colon biopsy specimens from 45 UCBT recipients and 45 matched allografted controls obtained between day +70 and day +365 post-transplantation. Diarrhea was the primary indication for biopsy in 10 UCBT recipients and 11 controls. No histological differences were seen between UCBT recipients and controls with diarrhea or between the entire cohort of UCBT recipients and their controls. Distorted mucosal architecture and apoptotic crypt cells typical of GVHD were common in both groups; Paneth cell metaplasia and granulomas were rare findings. Chronic active colitis was present in 58% of the UCBT recipients and in 62% of controls. No UCBT recipient with diarrhea was treated with antibiotics, and all recipients responded to systemic corticosteroids. Colitis occurring after day +70 in allografted controls was related to acute GVHD, independent of the source of donor cells. We could not identify a histologically distinct cord colitis syndrome in either the UCBT or the non-cord blood allograft recipients.

Stable long-term pulmonary function after myeloablative double cord blood transplant.

Pulmonary dysfunction has been well described after myeloablative transplantation with conventional allogeneic donors; however, whether the risk is similar after alternative donor transplantation with cord blood as the stem cell source has not yet been investigated. We performed a retrospective analysis of patients who underwent double cord blood transplantation after myeloablative conditioning. Pulmonary function tests were performed pretransplantation and at day 80, 1 year, and 2 years posttransplantation, with 56 patients included in the final analysis. No significant change from baseline with respect to the mean values and mean change in pulmonary function test values were observed at 1 year posttransplantation. The rate of lung function decline from baseline to 1 year posttransplantation was <5% in 75% patients; mildly abnormal lung function was reported in 58% of the patients. The cumulative incidence of noninfectious pulmonary complications was 9.7%. Future prospective studies are needed to confirm these findings.

Intensive strategy to prevent CMV disease in seropositive umbilical cord blood transplant recipients.

Seropositive umbilical cord blood transplant (UCBT) recipients are at increased risk for CMV complications. To reduce CMV complications, we adopted an intensive strategy that consisted of ganciclovir administered before transplantation (5 mg/kg intravenously daily from day -8 to day -2), high-dose acyclovir (2 g, 3 times daily) after transplantation, and biweekly monitoring with a serum CMV PCR for preemptive therapy. Hazard rates and cumulative incidence of CMV complications along with days treated were compared in high-risk CMV-seropositive UCBT recipients who received the intensive strategy and a historical cohort who received a standard strategy. Of 72 seropositive patients, 29 (40%) received standard prophylaxis and 43 (60%) the new intensive approach. The hazard rate (HR) for CMV reactivation was lower for patients receiving the intensive strategy (HR 0.27, 95% confidence interval 0.15-0.48; P < .001) and led to fewer cases of CMV disease by 1 year (HR 0.11, 95% confidence interval 0.02-0.53; P = .006). In patients who reactivated, the intensive strategy also led to fewer days on CMV-specific antiviral therapy (median 42% [interquartile range 21-63] vs 70% [interquartile range 54-83], P < .001). Use of an intensive CMV prevention strategy in high-risk CMVseropositive UCBT recipients results in a significant decrease in CMV reactivation and disease.