[Strategy of the French Society of Childhood Cancer (SFCE) for pediatric nodular lymphocyte predominant lymphoma]. / Recommandations de la SFCE pour la prise en charge du lymphome de Hodgkin nodulaire à prédominance lymphocytaire de l'enfant et de l'adolescent.

Nodular Lymphocyte predominant Hodgkin lymphoma (NLPHL) are rare lymphomas in pediatric patients comprising less than 10 % of all Hodgkin lymphoma (HL). They are for the most part diagnosed at stage I or II and indolent with lymphadenopathy often preceding the diagnosis by many months/years. Survival is excellent. Historically, patients were treated according to classical HL protocols. Due to high toxicity and excellent prognosis, management of NLPHL shifted to de-escalation protocol with good results. No treatment beyond surgical resection was proposed for localized unique nodal disease completely resected. The closed European protocol (EuroNet PHL LP1) evaluated the efficacy of low intensity chemotherapy protocol based on CVP courses (cyclophosphamide vinblastine prednisone) for stage IA/IIA not fully resected. Final results are not yet available. Advanced stage NLPHL are rare and there is no clinical trial and no consensus treatment in children. The SFCE lymphoma committee recently established recommendations for staging and treatment of limited and advanced NLPHL in children based on current practices and published results. The goal was to allow homogeneous practice on a national scale. If incomplete resection for patients with stage I/IIA combination of low intensity chemotherapy (CVP) and rituximab is recommended. For intermediary and advanced stage intensification with AVD (adriamycine vinblastine dacarbazine) or CHOP courses (cyclophosphamide doxorubicine vincristine prednisone) combined with rituximab are advocated. In children, there is no indication for first-line local treatment with radiotherapy.

Impaired aerobic capacity in adolescents and young adults after treatment for cancer or non-malignant haematological disease.

PURPOSE: Childhood cancer survivors are at increased risk for cardiovascular disease. Maximal oxygen uptake (VO2max) is a major determinant of cardiovascular morbidity. The aim of this study was to compare aerobic capacity, measured by cardiopulmonary exercise test (CPET), of adolescents and young adults in remission with that of healthy controls and to identify the predictors of aerobic capacity in this population. METHOD: This is a controlled cross-sectional study. RESULTS: A total of 477 subjects (77 in remission and 400 controls), aged from 6 to 25 years, were included, with a mean delay between end of treatment and CPET of 2.9 ± 2.3 years in the remission group. In this group, the mean VO2max was significantly lower than in controls (37.3 ± 7.6 vs. 43.3 ± 13.1 mL/kg/min, P < 0.01, respectively), without any clinical or echocardiographic evidence of heart failure. The VAT was significantly lower in the remission group (26.9 ± 6.0 mL/kg/min vs. 31.0 ± 9.9 mL/kg/min, P < 0.01, respectively). A lower VO2max was associated with female sex, older age, higher BMI, radiotherapy, and hematopoietic stem cell transplantation. CONCLUSION: Impaired aerobic capacity had a higher prevalence in adolescents and young adults in cancer remission. This impairment was primarily related to physical deconditioning and not to heart failure. TRIAL REGISTRY: NCT04815447. IMPACT: In childhood cancer survivors, aerobic capacity is five times more impaired than in healthy subjects. This impairment mostly reflects early onset of physical deconditioning. No evidence of heart failure was observed in this population.

EBV-driven lymphoid neoplasms associated with pediatric ALL maintenance therapy.

The development of a second malignancy after the diagnosis of childhood acute lymphoblastic leukemia (ALL) is a rare event. Certain second malignancies have been linked with specific elements of leukemia therapy, yet the etiology of most second neoplasms remains obscure and their optimal management strategies are unclear. This is a first comprehensive report of non-Hodgkin lymphomas (NHLs) following pediatric ALL therapy, excluding stem-cell transplantation. We analyzed data of patients who developed NHL following ALL diagnosis and were enrolled in 12 collaborative pediatric ALL trials between 1980-2018. Eighty-five patients developed NHL, with mature B-cell lymphoproliferations as the dominant subtype (56 of 85 cases). Forty-six of these 56 cases (82%) occurred during or within 6 months of maintenance therapy. The majority exhibited histopathological characteristics associated with immunodeficiency (65%), predominantly evidence of Epstein-Barr virus-driven lymphoproliferation. We investigated 66 cases of post-ALL immunodeficiency-associated lymphoid neoplasms, 52 from our study and 14 additional cases from a literature search. With a median follow-up of 4.9 years, the 5-year overall survival for the 66 patients with immunodeficiency-associated lymphoid neoplasms was 67.4% (95% confidence interval [CI], 56-81). Five-year cumulative risks of lymphoid neoplasm- and leukemia-related mortality were 20% (95% CI, 10.2-30) and 12.4% (95% CI, 2.7-22), respectively. Concurrent hemophagocytic lymphohistiocytosis was associated with increased mortality (hazard ratio, 7.32; 95% CI, 1.62-32.98; P = .01). A large proportion of post-ALL lymphoid neoplasms are associated with an immunodeficient state, likely precipitated by ALL maintenance therapy. Awareness of this underrecognized entity and pertinent diagnostic tests are crucial for early diagnosis and optimal therapy.

Rhabdomyosarcoma with unknown primary tumor site: A report from European pediatric Soft tissue sarcoma Study Group (EpSSG).

BACKGROUND: Rhabdomyosarcoma (RMS) is an aggressive malignancy, and 20% of children present with metastases at diagnosis. Patients presenting with disseminated disease very occasionally have no clear evidence of a primary tumor mass. As these patients have rarely been investigated, we report on a series of patients with RMS and unknown primary tumor site registered in the Metastatic (MTS) RMS 2008 protocol (October 2008 to December 2016) coordinated by the European pediatric Soft tissue sarcoma Study Group. METHODS: Patients were administered nine cycles of induction chemotherapy, and 48 weeks of maintenance chemotherapy. Surgery and/or radiotherapy were planned after the first assessment of tumor response, and implemented after six cycles of chemotherapy. If feasible, radiotherapy to all sites of metastasis was recommended. RESULTS: We identified 10 patients with RMS and unknown primary site, most of them adolescents (median age 15.8 years, range: 4.6-20.4). Nine had fusion-positive alveolar RMS. Multiple organ involvement was identified in seven patients, two only had bone marrow disease, and one only had leptomeningeal dissemination. All patients were given chemotherapy, four were irradiated, and none had surgery. Three patients underwent allogeneic bone marrow transplantation. At the time of this analysis, only two patients are alive in complete remission: one had received radiotherapy; and one had a bone marrow transplant. CONCLUSIONS: RMS with unknown primary tumor occurs mainly in adolescents and is typically fusion-positive alveolar. Radiotherapy may be important, but survival is poor and patients should be offered enrollment in investigational trials.

Monocentric retrospective clinical outcome in a group of 13 patients with opsoclonus myoclonus syndrome, proposal of diagnostic algorithm and review of the literature.

BACKGROUND: Dancing eye syndrome or opsoclonus-myoclonus syndrome (OMS) is a very rare disease (incidence <1/5,000,000 per year), which is more prevalent in young children. Although it is not usually a cause of mortality, the aftermaths are not rare. METHODS: We performed an observational retrospective review of children diagnosed with OMS in our neuropediatric department from 1996 to 2020, with the objective of assessing the prognostic value of initial clinical features. All medical data from diagnosis to last follow-up were reviewed. We defined unfavorable evolution of OMS as persistence or worsening of symptoms. Subsequently, based on a literature review, our results and experience, a diagnostic algorithm was developed. RESULTS: A total of 13 OMS patients were included: 61.5% were male (n = 8), median age at diagnosis was 18 months (IR = 76), median treatment delay was 14 days (IR = 146) and OMS score at onset was 8 (IR = 11). The most frequent etiologies were neuroblastoma-associated and idiopathic OMS (38.46%; n = 5) of the patients, followed by post-infectious OMS (n = 3). All the patients were treated with corticosteroids, five required a surgical intervention (neuroblastoma group), and three required adjunctive immune therapy (immunoglobulins, cyclophosphamide and/or rituximab). We detected neurodevelopmental disorders in 38.46% (n = 5) of the patients, mainly attention deficit (n = 4), and persistent sleep disturbances (n = 4). The median OMS score at the end of follow-up was 1 (IR = 3). An important diagnostic delay, OMS score of ≥10 and age >1 year at onset may correlate with a higher risk of aftermaths. We detected a better prognosis in the post-infectious OMS, with full recovery occurring in 2/3 of patients. CONCLUSIONS: Early clinical suspicion is key to guarantee maximum response of treatment.

Rituximab in addition to LMB-based chemotherapy regimen in children and adolescents with primary mediastinal large B-cell lymphoma: results of the French LMB2001 prospective study.

Primary mediastinal large B-cell lymphoma (PMLBL) is a rare entity predominantly affecting adolescents and young adults. Recently, an international phase II trial in pediatric patients using dose-adjusted etoposide, doxorubicin, and cyclophosphamide with vincristine and prednisone plus rituximab (DA-EPOCH-R) failed to reproduce excellent survival reported in some adult studies. The optimal therapy regimen needs to be determined in this disease. The French prospective LMB2001 trial included all patients ≤18 years with mature B-cell lymphoma treated in French centers. For patients with PMLBL, treatment included four to eight courses of Lymphomes Malins B (LMB)-based chemotherapy without radiotherapy. From 2008, rituximab was added before each chemotherapy course. From 09/2001 to 03/2012, 42 patients with PMLBL were registered. The median age was 15 years (range, 8-18). Twenty-one patients were treated with chemotherapy plus rituximab. The median follow-up was 7.1 years (interquartile range, 5.8-11.1). Five-year event-free and overall survival were 88.1% (95% confidence interval (CI): 75.0-94.8) and 95.2% (95% CI: 84.0-98.7) for the whole population. The 5-year EFS was 81.0% (95% CI: 60.0-92.3) and 95.2% (95% CI: 77.3-99.2) (hazard ratio =0.24; 95% CI: 0.03- 2.2) and 5-year overall survival was 90.5% (95% CI: 71.1-97.3) and 100% for patients treated without and with rituximab, respectively. Only one of 21 patients treated with rituximab and LMB-based chemotherapy had local early treatment failure but achieved prolonged complete remission with second-line chemotherapy and radiotherapy. Intensive LMBbased chemotherapy with rituximab achieved excellent survival in children/adolescents with PMLBL. Further international prospective studies are required to confirm these results in this population.

Testicular Sertoli cell tumour and potentially testicular Leydig cell tumour are features of DICER1 syndrome.

DICER1 syndrome is a rare paediatric autosomal dominant inherited disorder predisposing to various benign and malignant tumours. It is caused by a germline pathogenic variant in DICER1, and the second hit for tumour development is usually a missense hotspot pathogenic variant in the DICER1 ribonuclease IIIb domain. While DICER1 predisposing variants account for about 60% of ovarian Sertoli-Leydig cell tumours, no DICER1-related testicular stromal tumours have been described. Here we report the first two cases of testicular stromal tumours in children carrying a DICER1 germline pathogenic variant: a case of Sertoli cell tumour and a case of Leydig cell tumour diagnosed at 2 and 12 years of age, respectively. A somatic DICER1 hotspot pathogenic variant was detected in the Sertoli cell tumour. This report extends the spectrum of DICER1-related tumours to include testicular Sertoli cell tumour and potentially testicular Leydig cell tumour. Diagnosis of a testicular Sertoli cell tumour should prompt DICER1 genetic testing so that patients with a DICER1 germline pathogenic variant can benefit from established surveillance guidelines. DICER1 genetic evaluation may be considered for testicular Leydig cell tumour. Our findings suggest that miRNA dysregulation underlies the aetiology of some testicular stromal tumours.

Dose-Adjusted Etoposide, Doxorubicin, and Cyclophosphamide With Vincristine and Prednisone Plus Rituximab Therapy in Children and Adolescents With Primary Mediastinal B-Cell Lymphoma: A Multicenter Phase II Trial.

PURPOSE: A dose-adjusted etoposide, doxorubicin, and cyclophosphamide with vincristine and prednisone plus rituximab (DA-EPOCH-R) regimen has been shown to deliver excellent survival for adults with primary mediastinal large B-cell lymphoma (PMLBL) without the use of radiotherapy. No international prospective evaluation of this regimen has previously been reported in children and adolescents. PATIENTS AND METHODS: We conducted an international single-arm phase II trial involving patients younger than age 18 years with PMLBL who were to receive six courses of DA-EPOCH-R. The primary end point was event-free survival (EFS). Overall survival and toxicity were also assessed. This trial was registered (ClinicalTrials.gov identifier: NCT01516567). RESULTS: Analyses were based on 46 patients. The median age was 15.4 years (interquartile range: 14-16 years). The median follow-up was 59.0 months (interquartile range: 52.6-69.2 months). Fourteen events were observed (eight relapses or progressions (including three parenchymal CNS relapses), four residual lymphoma, and two second malignancies). The 4-year EFS was 69.6% (95% CI, 55.2 to 80.9), which did not differ from the rate observed historically (P = .59). Seven deaths occurred (six disease-related and one second malignancy). The overall survival was 84.8% (95% CI, 71.8 to 92.4). Twenty-two patients (48%) reached dose levels ≥ 4. Nonhematologic adverse events grade ≥ 3 or cardiac adverse events grade ≥ 2 occurred in 47 of 276 (17%) courses and 30 of 46 patients (65%). CONCLUSION: DA-EPOCH-R did not improve the EFS compared with a historical control in this first prospective multisite international study of children and adolescents with PMLBL. Further studies are required to determine the optimum therapy for children and adolescents with this lymphoma.

Primary post-transplant lymphoproliferative disorder of the central nervous system: characteristics, management and outcome in 25 paediatric patients.

Primary central nervous system (CNS) post-transplant lymphoproliferative disorder (PTLD) in childhood is rare. Twenty-five patients were retrieved from nine European Intergroup for Childhood Non-Hodgkin's Lymphoma and/or international Berlin-Frankfurt-Münster Study Group members. Types of allografts included kidney (n = 11), liver (n = 4), heart (n = 5), bowel (n = 1) and haematopoietic stem cells (n = 4). Eighteen were male, 16 ≥ 10 years old, 21 had monomorphic disease and 24 solid intracranial tumour masses. Four-year event-free and overall survival rates were 50% ± 10% and 74% ± 9% respectively. This report represents the largest paediatric series of CNS PTLD reported to date, showing favourable survival odds following systemic and intrathecal chemotherapy and rituximab administration.

Optimized blood culture strategy to document febrile neutropenia.

BACKGROUND: Poor and delayed microbiological documentation of episodes of febrile neutropenia (EFN) deserves improvement. We assessed the impact of a new blood culture (BC) sampling protocol to optimize the diagnosis of bloodstream infection during EFN, compared with standard of care protocol. METHODS: This pre/post intervention included patients who presented an EFN in a pediatric hematology-oncology center. Data were compared between 1-year periods P1 (110 EFN, 53 patients) and P2 (124 EFN, 53 patients). Pre-intervention settings were 1-2 mL of blood cultured per BC set and several samplings over days (multisampling strategy) during period P1 vs. one unique early sampling of a large volume of blood (0.5-60 mL) depending on patient weight during period P2 (single-sampling weight-adapted strategy). Microbial detection and time-to-diagnosis were evaluated. RESULTS: Seventeen EFNs were microbiologically documented in P1 (15.5%) and 26 in P2 (21%). The rate of positive BC sets increased during P2 (10.4% vs. 5.8%). All cases of bacteremia were documented by BC drawn during the first 4 days of fever, and during P2 by samples obtained on the first day of fever. CONCLUSIONS: Bacteremia detection was improved. This proof-of-concept study shows benefits of combining the single-sampling strategy with large weight-adapted blood sampling strategy during EFN. IMPACT: Combination of single-sampling and weight-adapted blood culture strategies showed benefits in the documentation of bloodstream infections during febrile neutropenia. Bacteremia detection was improved in this preliminary study and this warrants further evaluation in the overall pediatric population. We observed no adverse effects associated with the new strategy while overall blood sparing was improved and handling of intravascular devices was reduced. The good tolerance of the blood sampling suggests that the recommended 1% volume limitation in children could be reconsidered. A similar evaluation is justified in the overall pediatric population suspected for bloodstream infection.

In childhood mature B-NHL with CNS disease, patients with blasts in cerebrospinal fluid are at higher risk of failure.

To identify the factors influencing outcome in childhood mature B-cell non-Hodgkin lymphoma and acute leukemia (B-NHL/AL) with central nervous system (CNS) disease (CNS+), we analyzed patients <18 years with newly diagnosed B-NHL/AL registered in 3 Lymphomes Malins B studies in France between 1989 to 2011. CNS+ was diagnosed on fulfillment of ≥1 of the following criteria: any L3 cerebrospinal fluid (CSF) blasts (CSF+), cranial nerve palsy, isolated intracerebral mass but also clinical spinal cord compression, and cranial or spinal parameningeal extension. Two hundred seventeen out of 1690 patients (12.8%) were CNS+. CNS+ was significantly associated with male gender, head/neck locations, Burkitt histology, high initial lactate dehydrogenase (LDH) level, and bone marrow involvement. CSF+ was the most frequent pattern of CNS+ (45%). For the 217 CNS+ patients, the 5-year event-free survival (EFS) and overall survival rates (95% confidence interval) were 81.5% (75.8% to 86.1%) and 83.9% (78.4% to 88.2%), respectively. In multivariate analysis, among CNS+ patients, low EFS was associated with CSF+, high initial LDH level, and poor response to cyclophosphamide, oncovin (vincristine), prednisone prephase. These findings have been considered for patient's stratification in the international randomized phase 3 trial Inter-B-NHL-ritux 2010 for children and adolescents with high-risk B-NHL/AL with CNS+ CSF+ patients only receiving intensified chemotherapy.

Outcome of relapse in children and adolescents with B-cell non-Hodgkin lymphoma and mature acute leukemia: A report from the French LMB study.

INTRODUCTION: In order to describe relapsed B-cell non-Hodgkin lymphoma and mature acute leukemia in children/adolescents treated with the Lymphomes Malins B (LMB) regimen and their outcome in the rituximab era, relapses in the French LMB2001 study were reviewed. METHODS: Between February 2001 and December 2011, 33 patients out of 773 (4.3%) relapsed; 27 had Burkitt lymphoma and six large B-cell histology. Median age at diagnosis was 10.1 years. One patient was initially treated in risk group A, 21 in group B, and 11 in group C. RESULTS: Median time to relapse after diagnosis was 4.5 months (range 2.4-13.6). Thirty-two patients received salvage therapy. Twenty-seven received rituximab mainly in addition to high-dose cytarabine and etoposide (n = 18) and/or ifosfamide, carboplatin, and etoposide (n = 7). First-line salvage chemotherapy response rate was 66% with 47% being complete remission (CR). Twenty-one patients received high-dose chemotherapy (HDC) followed by autologous (n = 13) or allogeneic (n = 8) transplant. With a median follow-up of 6.8 years, the 5-year survival rate after relapse was 36.4% (95% confidence interval [CI] 22-53%). Twelve patients were still alive; all but one (group A) received consolidation treatment. Achieving CR before consolidation was significantly associated with better survival, with a 5-year survival rate of 75% (95% CI 46.8-91.1%) for patients in CR before HDC, 33% (95% CI 9.7-70%) for patients in partial remission, and 0% for nonresponders (P = .033). CONCLUSION: Survival of children/adolescents with mature B-cell lymphoma/leukemia remains poor after relapse with no apparent improvement with rituximab. Response rates to salvage chemo-immunotherapies are insufficient and new drugs are urgently needed to improve disease control.

Appendicitis in a Neutropenic Patient: A Multicentric Retrospective Study.

To study the management of acute appendicitis in neutropenic patients, we retrospectively reviewed cases of acute appendicitis in neutropenic children treated for cancer. The patients' demographics, medical records, and outcomes were tracked. We compared nonoperative treatment versus emergency or delayed surgery. The cases of 30 patients with a mean age of 8.8 years in 12 French departments of Pediatric Hematology/Oncology between 1995 and 2013 were studied. Most patients (90%) were treated for hematological malignancies. Seven of the 30 children were successfully treated with exclusive medical treatment. Early surgery was performed in 6 patients, and the remaining 17 underwent combined management with a first-line antibiotic treatment and delayed appendectomy. Treatments were successful in all cases with transitory complications in only 3 patients. No death linked to infection was reported. Surgery was well tolerated even in the neutropenic period. Appendix perforation was a major risk factor of prolonged hospitalization. Histologic as well as bacteriologic and mycologic/parasitologic analyses were required in case of surgery. Analysis of diagnostic assessments showed the major importance of imaging (ultrasonography and tomography) on diagnosis confirmation. We could not come to a conclusion in the few numbers of reviewed cases because of a significant difference in management strategies, but we can conclude that early surgery after adequate supportive care is an acceptable modality of treatment and must be chosen in the face of life-threatening conditions.

Advanced stage nodular lymphocyte predominant Hodgkin lymphoma in children and adolescents: clinical characteristics and treatment outcome - a report from the SFCE & CCLG groups.

Advanced stage nodular lymphocyte predominant Hodgkin lymphoma (nLPHL) is extremely rare in children and as a consequence, optimal treatment for this group of patients has not been established. Here we retrospectively evaluated the treatments and treatment outcomes of 41 of our patients from the UK and France with advanced stage nLPHL. Most patients received chemotherapy, some with the addition of the anti CD20 antibody rituximab or radiotherapy. Chemotherapy regimens were diverse and followed either classical Hodgkin lymphoma or B non-Hodgkin lymphoma protocols. All 41 patients achieved a complete remission with first line treatment and 40 patients are alive and well in remission. Eight patients subsequently relapsed and 1 patient died of secondary cancer (9 progression-free survival events). The median time to progression for those who progressed was 21 months (5·9-73·8). The median time since last diagnosis is 87·3 months (8·44-179·20). Thirty-six (90%), 30 (75%) and 27 (68%) patients have been in remission for more than 12, 24 and 36 months, respectively. Overall, the use of rituximab combined with multi-agent chemotherapy as first line treatment seems to be a reasonable therapeutic option.

Bacteremia due to imipenem-resistant Roseomonas mucosa in a child with acute lymphoblastic leukemia.

Roseomonas are described as opportunistic pathogens rarely involved in human infections. Their identification requires molecular methods and their antimicrobial susceptibility pattern varies according to the species. We report the first case of bacteremia due to Roseomonas mucosa in a child with leukemia and reviewed pediatric cases of Roseomonas infection, for which undoubted strain identification was available. Favorable outcome was observed despite resistance to numerous ß-lactams that may account for delayed effective treatment, suggesting the low virulence of Roseomonas in children. Here, the strain also displayed unusual resistance to imipenem, highlighting the possible acquisition of additional resistance by this pathogen.

Prenatal intrarenal neuroblastoma mimicking a mesoblastic nephroma: a case report.

Mesoblastic nephroma is by far the most frequent intrarenal fetal tumor. To the best of our knowledge, we report the first case of a newborn with an intrarenal neuroblastoma that was discovered prenatally. An intrarenal echogenic and homogenous mass was observed on routine prenatal ultrasonography, corroborated by magnetic resonance imaging, in a 30-week gestation fetus. A male weighing 3280 g was born with elevated blood pressure and cardiac failure. Postnatal ultrasound confirmed a left intrarenal tumor with microcalcifications and perirenal adenopathy. An open total left nephrectomy by laparotomy was performed. The pathologic study reported that the mass was an intrarenal neuroblastoma with local and regional invasion. Immediate postoperative urine analysis revealed a high level of vanillylmandelic acid, and blood samples showed high levels of normetanephrine. The purpose of this report is to demonstrate that prenatal intrarenal neuroblastoma can clinically and radiologically mimick a mesoblastic nephroma. High blood pressure, calcifications, and lymphadenopathy on ultrasound should raise the index of suspicion for a possible malignant process. Preoperative measurement of urinary vanillylmandelic acid (VMA) and metanephrines should be performed if the diagnosis is in doubt.

Folic acid supplementation, MTHFR and MTRR polymorphisms, and the risk of childhood leukemia: the ESCALE study (SFCE).

PURPOSE: Fetal folate deficiency may increase the risk of subsequent childhood acute leukemia (AL), since folates are required for DNA methylation, synthesis, and repair, but the literature remains scarce. This study tested the hypothesis that maternal folic acid supplementation before or during pregnancy reduces AL risk, accounting for the SNPs rs1801133 (C677T) and rs1801131 (A1298C) in MTHFR and rs1801394 (A66G) and rs1532268 (C524T) in MTRR, assumed to modify folate metabolism. METHODS: The nationwide registry-based case-control study, ESCALE, carried out in 2003-2004, included 764 AL cases and 1,681 controls frequency matched with the cases on age and gender. Information on folic acid supplementation was obtained by standardized telephone interview. The genotypes were obtained using high-throughput platforms and imputation for untyped polymorphisms. Odds ratios (OR) were estimated using unconditional regression models adjusted for potential confounders. RESULTS: AL was significantly inversely associated with maternal folic acid supplementation before and during pregnancy (OR = 0.4; 95 % confidence interval: [0.3-0.6]). MTHFR and MTRR genetic polymorphisms were not associated with AL. However, AL was positively associated with homozygosity for any of the MTHFR polymorphisms and carriership of both MTRR variant alleles (OR = 1.6 [0.9-3.1]). No interaction was observed between MTHFR, MTRR, and maternal folate supplementation. CONCLUSION: The study findings support the hypothesis that maternal folic acid supplementation may reduce the risk of childhood AL. The findings also suggest that the genotype homozygous for any of the MTHFR variants and carrying both MTRR variants could be a risk factor for AL.