The impact of Treosulfan-based conditioning for inborn errors of immunity: Is dose monitoring crucial?

INTRODUCTION: In children with inborn errors of immunity (IEI) who will receive a hematopoietic stem cell transplant (HSCT) treosulfan-based conditioning is currently preferred. The aim of this study was to investigate early and late outcomes in pediatric IEI patients receiving pre-HSCT treosulfan and to examine the effect of treosulfan dose monitoring on outcomes. METHODS: Seventy-three pediatric patients receiving this management between 2015 and 2022 were included. RESULTS: Overall survival rate was 80%, and event-free survival was 67.8%. A larger treosulfan dose AUC after first application increased the rate of early toxicity (p = .034) and slowed lymphocyte engraftment (r = .290; p = .030). Underlying disease, treosulfan AUC, donor type, stem cell type, number of immunosuppressive agents, the dose of anti-thymocyte globulin, and post-transplantation cyclophosphamide did not to increase risk of acute graft-versus-host disease. The risk of mixed chimerism (MC) in patients with autoimmune lymphoproliferative syndrome and leukocyte adhesion deficiency were higher than those with severe combined immunodeficiency (p = .021 and p = .014, respectively). The risk of MC was lower in those receiving peripheral blood stem cells (SC) compared with bone marrow derived SC (OR = .204, p = .022). CONCLUSION: The AUC of the treosulfan dose was not associated with poorer late outcomes. Treosulfan is an agent that can be used safely in the IEI patient group,  level measurement appears essential to identify early toxicities. Prospective studies with more extended follow-up periods are needed.

Evaluation of the risk factors for BK virus-associated hemorrhagic cystitis in pediatric bone marrow transplantation patients: Does post-transplantation cyclophosphamide increase the frequency?

BACKGROUND: BKV-HC is one of the most significant complications of HSCT. This retrospective study aimed to determine the frequency of BKV-HC in pediatric patients undergoing HSCT, detect the associated risk factors for the development of BKV-HC, and explore the effects of post-transplantation Cy use. METHODS: Three hundred twenty-seven patients (girls: 121, boys: 206) were analyzed according to sex, conditioning regimen, transplantation type, donor relatedness, stem cell source, the presence and grade of aGVHD, CMV co-existence, and Cy use. RESULTS: Multivariate analysis confirmed the prognostic importance of age (OR: 4.865), TBI use, the presence of aGVHD (OR: 2.794), CMV coinfection (OR: 2.261), and Cy use (OR: 27.353). A statistically significant difference was found between the mean BKV-HC follow-up times compared with post-transplantation Cy intake (p < .001). The BKV-HC rate increased as the number of risk factors of the patient increased. CONCLUSION: BKV-HC is an essential complication of HSCT primarily associated with Cy use, the presence of aGVHD, and donor relatedness. The present study shows that the use of Cy in the post-transplantation period further increases BKV-HC risk in pediatric patients, regardless of dose.

Evaluation of clinical and laboratory characteristics of childhood tuberculosis.

AIM: Tuberculosis is one of the oldest and most contagious diseases of human history. One- quarter of the world's population is infected with the tuberculosis bacillus. Childhood tuberculosis does not have a standard clinical and radiologic description. Herein, we aimed to evaluate the clinical, laboratory, and radiologic findings of childhood tuberculosis. MATERIAL AND METHODS: The medical records of 216 patients hospitalized and treated with a diagnosis of TB between January 2015 and July 2019 in the Division of Pediatric Infectious Diseases in our hospital, were examined retrospectively. RESULTS: One hundred twenty-nine (59.7%) of 216 patients who were diagnosed as having TB were female and 87 (40.3%) were male. The age distribution of the patients was 12.3 (range, 0.33-18) years. One hundred sixty-nine patients (78.2%) had pulmonary, 34 (15.7%) had extrapulmonary, 13 had (6%) both pulmonary and extrapulmonary. One hundred forty-three (66.2%) patients had tuberculin skin test positivity. Acid-resistant bacteria were observed in 46 (21.3%) body fluid samples, and culture positivity was observed in 42 (19.4%) samples. The association of pulmonary tuberculosis and extrapulmonary tuberculosis was found with a higher rate in individuals who lived on minimum wage and in patients who had growth and developmental retardation (p=0.001, p<0.001). The hospitalization time was longer in these patients (p=0.027). The hemoglobin and sodium levels were significantly lower in patients who had extrapulmonary tuberculosis (p=0.044, p=0.002). CONCLUSION: Although the diagnosis of childhood tuberculosis is difficult due to the nonspecific signs and symptoms, it is a preventable and treatable disease.