ADV has emerged as an important pathogen in children undergoing allogeneic HPCT. A prospective study of the epidemiology of ADV infection and preemptive therapy of high risk ADV infections in children undergoing HPCT was undertaken. Cultures of throat, urine, and stool for viral pathogens and plasma for ADV PCR were obtained prior to transplantation, weekly for the first 100 days, and then monthly for one yr. Children developing high-risk ADV infections were treated preemptively with cidofovir 1 mg/kg/day given three times weekly for three wk. A case-controlled study was performed to identify risk factors for high-risk ADV infections. Seven (18%) of the 38 subjects developed high-risk ADV infections usually within 100 days of HPCT and were preemptively treated with i.v. cidofovir at a dose of 1 mg/kg/dose three times weekly for nine doses. High-risk ADV infections resolved in all seven patients without renal toxicity. CMV viremia occurred in two of seven patients during or shortly after therapy with cidofovir. A case-control study did not identify any risk factors that achieved statistical significance. Treatment with a modified dosing regimen of cidofovir was well-tolerated and high-risk ADV infections resolved in all patients.

Apheresis procedures in small children are technically challenging and require special planning with attention to extracorporeal volume. Discontinuous procedures such as extracorporeal photopheresis (ECP) require additional consideration. Alternative methods to perform ECP have been utilized in small children that require manipulation of mononuclear cells outside the standard closed-loop system. We present a safe and feasible alternative to the procedure for children who weigh less than 40 Kg, while maintaining a closed loop, sterile system utilizing the UVAR XTS device. A retrospective chart review was performed analyzing the use of fluid boluses (normal saline in those between 20 and 40 Kg, 5% albumin in those under 20 Kg) before ECP. Eleven patients underwent 334 ECP procedures for acute and chronic graft-versus-host disease (n 5 9), and for prevention of graft-versus-host disease (n 5 2). Volumes of fluid boluses were calculated based on the expected extracorporeal volume during the first draw cycle. Treatments consisted of at least three draw cycles using the 125 mL bowl. The median weight was 28.5 Kg (range 19 to 39); nine of 11 required red cell transfusions to maintain adequate hematocrit. Complications attributed to ECP included tachycardia, dizziness, nausea, and hypotension; these occurred either in combination or isolation in 31% of the procedures and resolved following additional fluid boluses. Only three (0.8%) required early photoactivation due to these complications. The median time to completion of treatment was 2 h and 58 min (range 1:30 to 5:03). ECP is well tolerated in low-weight pediatric patients if hematocrit and hydration are carefully maintained. J. Clin. Apheresis 25:63-69, 2010. V V C 2010 Wiley-Liss, Inc.

Finding predictors of chronic graft-versus-host disease (cGVHD) in children would be extremely useful. Because of recent data suggesting that cGVHD may be a Th-2-mediated process, a theoretical foundation linking eosinophilia and cGVHD exists. While an association between eosinophilia and cGVHD has been described in adults, it has never been described in children. We studied 53 patients that received allogeneic hematopoietic stem cell transplants (SCT) between 1999 and 2002. Ten (19%) of these patients developed eosinophilia (absolute eosinophil count (AEC) > 500x 10/L) after day 100. Of these ten, eight either had or later developed cGVHD. We conclude that following the peripheral eosinophil count in children post-SCT is useful, and a rise in the AEC may herald the development of cGVHD. Taking the AEC into account with other risk factors (such as previous grade II-IV acute GVHD, human leukocyte antigen (HLA)-mismatch, and unrelated donor (URD) transplant) may improve our ability to predict cGVHD.