OBJECTIVE: The aim of this study was to analyze and identify documented infections and possible risk factors for Clostridioides difficile infections in children with cancer.
METHODS: This is a retrospective case-control study, carried out in a pediatric cancer hospital, covering the years 2016-2019. Matching was performed by age and underlying disease, and for each case, the number of controls varied from 1 to 3. Logistic regression models were used to assess risk factors.
RESULTS: We analyzed 63 cases of documented infection by C. difficile and 125 controls. Diarrhea was present in all cases, accompanied by fever higher than 38°C in 52.4% of the patients. Mortality was similar among cases (n=4; 6.3%) and controls (n=6; 4.8%; p=0.7). In all, 71% of patients in the case group and 53% in the control group received broad-spectrum antibiotics prior to the infection. For previous use of vancomycin, the Odds Ratio for C. difficile infection was 5.4 (95% confidence interval [95%CI] 2.3-12.5); for meropenem, 4.41 (95%CI 2.1-9.2); and for cefepime, 2.6 (95%CI 1.3-5.1). For the antineoplastic agents, the Odds Ratio for carboplatin was 2.7 (95%CI 1.2-6.2), melphalan 9.04 (95%CI 1.9-42.3), busulfan 16.7 (95%CI 2.1-134.9), and asparaginase 8.97 (95%CI 1.9-42.9).
CONCLUSIONS: C. difficile symptomatic infection in children with cancer was associated with previous hospitalization and the use of common antibiotics in cancer patients, such as vancomycin, meropenem, and cefepime, in the last 3 months. Chemotherapy drugs, such as carboplatin, melphalan, busulfan, and asparaginase, were also risk factors.

We report three adult patients with primary immunodeficiency (PID) treated with reduced-intensity allogenic hematopoietic cell transplantation (HCT) with fludarabine/treosulfan conditioning and graft-versus-host disease (GvHD) prophylaxis with alemtuzumab and a calcineurin inhibitor.
Patient 1, a 51-year-old male, had common variable immunodeficiency (CVID) with protein-losing enteropathy. Patient 2 was a 29-year-old woman with STAT3 (signal transducer and activator of transcription 3)-dependent hyper-IgE syndrome (HIES). Patient 3 was a 25-year-old male with XIAP (X-linked inhibitor of apoptosis)-deficiency presenting as treatment-refractory granulomatous enteropathy. Engraftment occurred in all three patients, with 100% donor chimerism in blood. Two patients survived, whereas the patient with CVID died due to infection.
This series highlights issues of transplantation for PID in adults and treosulfan-based conditioning, which is feasible for PID patients; infectious complications are the major issue of concern.

In busulfan-based conditioning regimen for hematopoietic stem cell transplantation in children, accurate a priori determination of the first dose is important because of its narrow therapeutic window. Sickle cell disease (SCD) influences pharmacokinetics of the commonly used drugs by affecting organs responsible for drug metabolism and elimination. This pharmacokinetics study assesses the influence of SCD on the metabolic pathway of busulfan that is mainly metabolized in the liver. In this retrospective cross-sectional case-control study, 16 patients with SCD were matched to 50 patients without SCD on known busulfan clearance\'s covariates (glutathione-S-transferase alpha1 polymorphisms, age, weight). Clearance of the first dose of busulfan was not significantly different independently of genetic or anthropometric factors in patients with or without SCD.

Chediak-Higashi syndrome is a rare immunodeficiency disorder for which hematopoietic stem cell transplant (HSCT) is the only curative treatment option. HSCT only corrects the hematologic and immunologic manifestations of the disease but neurologic complications may still progress after transplant. Haploidentical HSCT (haplo-HSCT) has evolved as a feasible alternative for patients with primary immunodeficiency. More recently, there has been use of haplo-HSCT with post-transplant cyclophosphamide. However, only 4 cases of Chediak-Higashi syndrome have been reported using this approach. Here, the authors describe a case of a 17-month-old boy who was successfully treated by haplo-HSCT with reduced-toxicity conditioning (fludarabine/treosulfan/melphalan) and post-transplant cyclophosphamide.

Busulfan is an alkylating agent routinely used in conditioning regimens prior to allogeneic hematopoietic cell transplantation (HCT) for various nonmalignant disorders, including inborn errors of metabolism. The combination of model-based dosing and therapeutic drug monitoring (TDM) of busulfan pharmacokinetics (PK) to a lower exposure target has the potential to reduce the regimen-related toxicity while opening marrow niches sufficient for engraftment in diseases such as mucopolysaccharidosis type I (MPS I). We present four cases of the severe form of MPS I or Hurler syndrome, demonstrating successful and stable CD14/15 donor chimerism following the prospective application of model-based dosing and TDM aimed to achieve lower busulfan exposure. All patients received a busulfan-based conditioning regimen with a median cumulative area-under-the-curve (cAUC) target of 63.7 mg h/L (range, 62.4 to 65.0) in protocol-specific combination of chemotherapeutic regimen. The donor source was unrelated umbilical cord blood for three patients and matched sibling donor bone marrow for one patient. The observed median busulfan cAUC was 66.1 mg h/L (range, 65.2 to 70.6) and was within 10% of the intended target. Stable, full donor myeloid chimerism was achieved for three patients, while one patient achieved a stable mixed chimerism (76% donor CD14/15 at 53 months) without a recurring need for enzyme replacement. The normalization of α-L-iduronidase enzyme levels followed the attainment of successful donor myeloid chimerism in all patients. Regimen-related toxicity remained low with no evidence of acute graft-versus-host disease (GVHD) grades II to IV and chronic GVHD.

Juvenile xanthogranuloma (JXG) is a rare histiocytic disorder classified as non-Langerhans cell histiocytosis; although it is usually a benign and self-limiting disease, it can be fatal in some cases, especially with systemic dissemination. We present a case report of a boy with therapy-resistant disseminated JXG who was treated with systemic chemotherapy and received 3 allogeneic hematopoietic stem cell transplantations (allo-HSCTs) from an unrelated donor. The post-transplant period was complicated by acute graft vs host disease and lymphoproliferative disease caused by Epstein-Barr virus. Currently, almost 7.5 years after the first transplantation, the boy is in complete remission with full donor chimerism and without symptoms of JXG. The presented data confirm rare observations that allo-HSCT can lead to durable remission of systemic JXG, which warrants its use in life-threatening, therapy-resistant subtypes of disease.

BACKGROUND: Primary refractory acute myeloid leukemia (AML) is associated with dismal prognosis. No standard treatment options are available, and it remains an unmet clinical need. Here, we report a case of a tandem allogeneic hematopoietic stem cell transplantation (allo-HSCT) performed in a patient who did not achieve remission after 2 courses of induction chemotherapy.
UNASSIGNED: The treatment was approved by the Bioethical Commission of the Medical University of Warsaw and was performed in accordance with the Declaration of Helsinki. The patient gave informed consent.
RESULTS: A 41-year-old woman was diagnosed with AML, high cytogenetic risk, with concomitant skin and central nervous system involvement, bone marrow necrosis, and hemophagocytic lymphohistiocytosis. She received \"3+7\" induction and HAM (cytarabine, mitoxantrone) reinduction, after which she did not achieve remission and hematopoietic recovery. Tandem allo-HSCT was performed from the same HLA-identical brother---the first after reduced intensity conditioning (cladribine, cytarabine, mitoxantrone, melphalan) and the second after myeloablative conditioning (BuCy--busulphan, cyclophosphamide). The patient obtained complete remission after the first allo-HSCT and remains disease-free after the second for 5 years CONCLUSION: Tandem allo-HSCT may be a treatment option for primary refractory AML.

Background: Impaired lung function has been detected in up to 65% of all childhood cancer survivors. It is often caused by exposure to radiation therapy and various chemotherapeutics. The first cytotoxic drug ever identified as a causative agent of lung injury was busulfan, reported in the early 1960s. Signs and symptoms of busulfan lung are nonspecific and it is therefore difficult to differentiate the condition from pulmonary impairment caused by other pulmotoxic agents, infections, pulmonary metastases, graft-versus-host disease, or other noninfectious post-transplant complications involving the lungs. Methods: A case example is provided to illustrate the difficulties in management of busulfan-induced lung injury in children. A retrospective review of cases of busulfan-induced lung injury indexed in PubMed until March 2019 was performed. Inclusion criteria for articles was available in full text in English. Results: Impaired lung function caused by busulfan may become an increasing problem for young survivors. Conclusion: Newly developed dyspnea or subclinical damage detected on pulmonary function tests, indicating primarily restrictive disease, should always arouse suspicion of busulfan-induced lung injury in a child conditioned with busulfan, especially after excluding other leading culprits of pulmonary damage affecting oncology patients.

BACKGROUND: X-linked EDA-ID1 (ectodermal dysplasia, anhidrotic, with immunodeficiency 1, Online Mendelian Inheritance in Man [OMIM] 300291), or NEMO (nuclear factor kappa B essential modulator) deficiency syndrome, is caused by mutations in the IKBKG/NEMO gene. We report the case of a boy with EDA-ID1 who underwent allogeneic stem cell transplantation.
METHODS: In early infancy, the patient developed an atypical, severe, initial manifestation resembling Omenn syndrome with infections, and he underwent allogeneic stem cell transplantation from an unrelated 9 of 10 HLA matched donor with a mismatch in the DQB1 allele after conditioning with treosulfan, fludarabine, thiotepa, and antithymocyte globulin (Grafalon). The post-transplant period was complicated by cytomegalovirus replication and mild, grade 2 graft vs host disease. Because of NEMO deficiency syndrome-associated enteropathy and continuous weight loss, parenteral nutrition was started and the patient was fed an elemental formula and a gluten-free diet. Over a period of 3 years, the patient had 7 incidents of blood stream infections caused by Staphylococci or gut-derived Gram-negative flora, with 1 incident of septic shock caused by Escherichia coli. The blood stream infection stopped after gastrointestinal tract decontamination was done once per month for 7-day courses alternately with rifaximin, vancomycin, and gentamicin sulfate.
CONCLUSIONS: Patients with NEMO deficiency syndrome require very complex, multidisciplinary care, and immunodeficiency correction can only be observed as one of the critical points in patient care. Developmental problems, enteropathy with the need for intravenous hyperalimentation, and specific interventions for other clinical manifestations of multifaceted syndrome are needed for proper care.

BACKGROUND: X-linked immunodysregulation syndrome with polyendocrinopathy and enteropathy (IPEX) is caused by FOXP3 gene mutations that block the generation of regulatory T lymphocytes. We report an 18-month-old boy with classic IPEX who underwent 2 hematopoietic stem cell transplantations (HSCTs).
METHODS: The first HSCT from an unrelated 8/10 HLA-matched umbilical cord blood donor (UCB) was performed after a conditioning regimen consisting of treosulfan, fludarabine, thiotepa, and thymoglobulin. Due to complete rejection of the UCB transplant, a second transplantation from a 6/10 HLA-matched mother was performed after alpha-beta T-cell depletion. The second conditioning regimen consisted of busulfan, fludarabine, a single dose of cyclophosphamide 1 g/m2, and Grafalon (Neovii Pharmaceuticals, Rapperswil, Switzerland). The T-cell depletion product contained 15.06 x 106 CD34+ cells per kilogram body weight (BW) and 4.19 x 105 alpha-beta T lymphocytes per kilogram BW. Due to acute graft rejection, the boy was treated with thymoglobulin, and full donor chimerism in both T lymphocytes and mononuclear cells was achieved. The immunosuppressive therapy was stopped 1 year after transplantation. To date, the patient remains free from graft-vs-host disease (GVHD) and immunosuppression.
CONCLUSIONS: HSCT after busulfan-based reduced-toxicity conditioning in patients with IPEX syndrome is feasible and well tolerated and can result in full donor engraftment. Monitoring of chimerism and aggressive therapy in cases of graft rejection are warranted due to the high reactivity of residual autologous T lymphocytes. T-cell depletion reduces the risk of GVHD and the need for steroid therapy, which is especially challenging in patients with diabetes.