Sirolimus is effective and safe in childhood relapsed-refractory autoimmune cytopenias: A multicentre study.

Autoimmune cytopenias are a heterogeneous group of disorders characterized by immune-mediated destruction of haematopoietic cell lines. Effective and well-tolerated treatment options for relapsed-refractory immune cytopenias are limited. In this study, the aim was to evaluate the efficacy and safety of sirolimus in this disease group within the paediatric age group. The study enrolled patients in the paediatric age group who used sirolimus with a diagnosis of immune cytopenia between December 2010 and December 2020, followed at six centres in Turkey. Of the 17 patients, five (29.4%) were treated for autoimmune haemolytic anaemia (AIHA), six (35.2%) for immune thrombocytopenic purpura (ITP) and six (35.2%) for Evans syndrome (ES). The mean response time was 2.7 months (range, 0-9 months). Complete response (CR) and partial response (PR) were obtained in 13 of 17 patients (76.4%) and nonresponse (NR) in four patients (23.5%). Among the 13 patients who achieved CR, three of them were NR in the follow-up and two of them had remission with low-dose steroid and sirolimus. Thus, overall response rate (ORR) was achieved in 12 of 17 patients (70.5%). In conclusion, sirolimus may be an effective and safe option in paediatric patients with relapsed-refractory immune cytopenia.

A child with intravascular fasciitis mimicking deep vein thrombosis: a case report.

BACKGROUND: Intravascular fasciitis (IF) is a benign, reactive, myofibroblastic proliferation that originates from the superficial or deep fascia of small / medium-sized arteries and veins. CASE REPORT: An 8-year-old male patient was admitted to a health center with the complaint of swelling in the inguinal region. Lower extremity venous Doppler ultrasonography showed deep vein thrombosis (DVT) of the femoral vein and anticoagulation with low-molecular weight heparin (LMWH) was initiated. The patient was referred to our center for follow-up. The D-dimer level was detected within normal limits. Doppler ultrasonography was repeated and showed an intraluminal expanding mass lesion with increasing vascularity, without distinct borders and LMWH was discontinued. This lesion at the sapheno-femoral junction was excised surgically and the histopathological examination revealed intravascular fasciitis. CONCLUSION: Clinicians should be aware that the clinical findings of IF may mimic sarcoma and thrombosis.

Successful management of delayed-onset adenosine deaminase deficiency with novel mutation.

A 4-year-old boy presented with acute-onset autoimmune cytopenia with severe, persistent lymphopenia, autoimmune thyroiditis, elevated IgE and glucose 6-phosphate dehydrogenase enzyme deficiency. In immunologic evaluation, lower T, B and natural killer cells and higher levels of adenosine deaminase (ADA) metabolites were observed. The compound heterozygous novel ADA gene mutations causing ADA deficiency were detected. Successful immunologic and metabolic cure was achieved with enzyme replacement therapy, followed by reduced intensity conditioning hematopoietic stem cell transplantation from a matched unrelated donor. An interesting aspect of this patient is the detection of novel compound heterozygous mutations without consanguinity and a secondary outcome is the recovery of glucose 6-phosphate dehydrogenase deficiency after hematopoietic stem cell transplantation.

Successful Treatment of a Child with Hemoglobin Hammersmith with Hematopoietic Stem Cell Transplantation.

Hemoglobin (Hb) Hammersmith, formed by serine substitution for phenylalanine at residue 42 in the beta-globin chain, is a very rare variant of unstable hemoglobin with low oxygen affinity. For patients with hemoglobinopathies, it is well-established that hematopoietic stem cell transplantation provides a complete cure, but the literature on its role for those with Hb Hammersmith is limited. A seven-month-old girl who was examined for anemia and splenomegaly was followed up for congenital hemolytic anemia. The patient with visible cyanosis of the lips and whose p50 was low in blood gas was diagnosed with Hb Hammersmith through the DNA sequence analysis. During the follow-up, frequent blood transfusions had to be given due to anemia aggravated by infections. Following a successful hematopoietic stem cell transplant from an HLA-matched sibling, the patient completely recovered from Hb Hammersmith. The case is presented because of its rarity.

Central nervous system thrombosis in pediatric acute lymphoblastic leukemia in Turkey: A multicenter study.

BACKGROUND: In patients with acute lymphoblastic leukemia (ALL), the risk of thromboembolism increases due to hemostatic changes secondary to the primary disease and due to treatment-related factors. In this multicenter study, we aimed to research the frequency of central nervous system (CNS) thrombosis occurring during treatment, hereditary and acquired risk factors, clinical and laboratory features of patients with thrombosis, treatment approaches, and thrombosis-related mortality and morbidity rates in pediatric ALL patients. PROCEDURE: Pediatric patients who developed CNS thrombosis during ALL treatment from 2010 to 2021 were analyzed retrospectively in 25 different Pediatric Hematology Oncology centers in Türkiye. The demographic characteristics of the patients, symptoms associated with thrombosis, the stage of the leukemia treatment during thrombosis, the anticoagulant therapy applied for thrombosis, and the final status of the patients recorded through electronic medical records were determined. RESULTS: Data from 70 patients with CNS thrombosis during treatment, out of 3968 pediatric patients with ALL, were reviewed. The incidence of CNS thrombosis was 1.8% (venous: 1.5 %; arterial: 0.03%). Among patients with CNS thrombosis, 47 had the event in the first 2 months. Low molecular weight heparin (LMWH) was the most commonly used treatment with a median of 6 months (min-max: 3-28 months). No treatment-related complications occurred. Chronic thrombosis findings occurred in four patients (6%). In five (7%) patients who developed cerebral vein thrombosis, neurological sequelae (epilepsy and neurological deficit) remained. One patient died related to thrombosis, and the mortality rate was 1.4%. CONCLUSION: Cerebral venous thrombosis and, less frequently, cerebral arterial thrombosis may develop in patients with ALL. The incidence of CNS thrombosis is higher during induction therapy than during other courses of treatment. Therefore, patients receiving induction therapy should be monitored carefully for clinical findings suggestive of CNS thrombosis.

Genetic basis and hematologic manifestations of sitosterolemia in a group of Turkish patients.

BACKGROUND: Sitosterolemia is a rare lipid disorder caused by mutations in adenosine triphosphate-binding cassette genes (ABCG) 5 and 8. OBJECTIVE: To evaluate the phenotypic/genotypic features of sitosterolemia in a group of Turkish patients. METHODS: Seven probands with unexplained hematologic abnormalities and their 13 relatives were enrolled. Sterol levels were measured by gas chromatography and genetic studies were performed using Sanger sequencing. Individuals were diagnosed with sitosterolemia if they were found to have frankly elevated sitosterol level >15 µg/mL and/or pathogenic variants of the ABCG5/ABCG8. RESULTS: The seven probands and their six relatives  were diagnosed with frank sitosterolemia, and all these patients had hematologic abnormalities. The remaining seven relatives were asymptomatic heterozygous carriers. Three novel variants in the ABCG5 gene (c.161G>A, c.1375C>T, IVS10-1G>T), one novel variant in the ABCG8 gene (c.1762G>C) and one known variant in the ABCG5 gene (c.1336 C>T) were identified. No variant was identified in one case. The mean sitosterol level was significantly higher and mean platelet count was significantly lower in patients with homozygous variants compared to heterozygous variants (p<0.05, for all). Diets low in plant sterols were recommended for 13 symptomatic cases. Four homozygotes received ezetimibe, and their splenomegaly, anemia, and thrombocytopenia completely resolved except one. CONCLUSION: The five pathogenic variants identified in this study indicate the genetic heterogeneity of sitosterolemia in Turkish population. Patients with unexplained hematologic abnormalities (specifically macrothrombocytopenia) should have their sterol level measured as initial testing. Ezetimibe can be a good choice for sitosterolemia.

The clinical findings and prophylactic treatment in children with factor X deficiency.

Factor X (FX) is the component of both extrinsic and intrinsic coagulation cascade and is the first enzyme of the common pathway which results in thrombus. Congenital FX deficiency (FXD) is an extremely rare coagulation defect. In this study, we aimed to investigate the clinical and laboratory data of the patients diagnosed with FXD. The files of the 15 patients (7 female, 8 male) diagnosed and followed up for FXD within the last 4 years were evaluated retrospectively. The mean age of the patients was 29 months (min-max:1-144 months). The most presenting complaints were easy bruisability (n = 8; 53%) and epistaxis (n = 8; 53%). FX levels were <1% in six patients, 1-5% in four patients, and >5% in five patients. Heparin added-Protrombin Complex was used for prophlaxy (n = 11; 73%). Any treatment-related complication was not observed. Heparin-added PCC can be used safely for effective prophlaxy. We suggest that family history is important when considering prophlaxy and in patients with life-threatening bleeding or with FXD sibling the prophlaxy should be introduced in the early course.