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Pediatric patients with MF present in the first decade of life, with early-stage disease and unusual forms such as hypopigmented variant. Further patient enrollment will provide information regarding natural history, treatment response, and overall prognosis of pediatric cutaneous T-cell lymphoma (CTCL).

Post-transplant Lymphoproliferative Disorder (PTLD) because of the Epstein-Barr Virus (EBV) is a major concern after pediatric transplantation. The group at greatest risk is EBV-seronegative recipients who receive EBV-seropositive organs. Additional risk factors remain to be determined, including those among EBV-seropositive recipients. In this case-control study, PTLD cases were biopsy-proven over a period of 4 yr (1997-2000, inclusive). Each case was matched with 2 controls, based on the type of organ transplanted and the period of transplantation (+/-1 yr). Variables compared between cases and controls included those relating to the clinical and virologic profiles and immunosuppressive therapy. Twenty-two cases of PTLD were diagnosed during the study period. PTLD cases occurred at a median of 22.8 months post-transplantation (range 1-131). The median age of cases was 26.2 months (range 6.1-194) compared with 47.4 months (range 0.8-202.2) for controls (p = 0.93). Cases had a higher mean baseline EBV load compared with controls (3.1 log(10) (s.d. +/- 1.0) vs. 1.6 log(10)/10(6) PBMCs (s.d. +/- 1.4), with every 1 log increase in viral load resulting in a three times increase in the likelihood of PTLD (p < 0.007). Close to one in four cases of PTLD were EBV-seropositive pretransplantation. These seropositive recipients tended to be older patients with a trend to a worse outcome compared with their seronegative counterparts. The occurrence of PTLD was not associated with the use of any specific immunosuppressants. A significant proportion of PTLD cases occurred among EBV-seropositive transplant recipients, with a tendency towards an unfavorable outcome. Besides EBV-seronegative recipients who receive seropositive organs, some EBV-seropositive pediatric patients are at risk of PTLD. Additional studies are warranted to further define the factors associated with PTLD in EBV-seropositive transplant recipients.

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The imaging appearance of CMN is often determined by the pathological type of tumor. Findings suggestive of the classic variant include a peripheral hypoechoic ring or large solid component. In comparison, cystic/necrotic change and hemorrhage is much more common in cellular CMN.

Positive autoantibodies are common in children after LT and their presence may denote a higher risk for the development of de novo AIH or chronic rejection over time.

Necrotizing enterocolitis (NEC) is a devastating neonatal disease characterized by acute intestinal injury. Intestinal stem cell (ISC) renewal is required for gut regeneration in response to acute injury. The Wnt/β-catenin pathway is essential for intestinal renewal and ISC maintenance. We found that ISC expression, Wnt activity and intestinal regeneration were all decreased in both mice with experimental NEC and in infants with acute active NEC. Moreover, intestinal organoids derived from NEC-injured intestine of both mice and humans failed to maintain proliferation and presented more differentiation. Administration of Wnt7b reversed these changes and promoted growth of intestinal organoids. Additionally, administration of exogenous Wnt7b rescued intestinal injury, restored ISC, and reestablished intestinal epithelial homeostasis in mice with NEC. Our findings demonstrate that during NEC, Wnt/β-catenin signaling is decreased, ISC activity is impaired, and intestinal regeneration is defective. Administration of Wnt resulted in the maintenance of intestinal epithelial homeostasis and avoidance of NEC intestinal injury.