Appropriate thresholds for accurate screening for ß-thalassemias in the newborn period: results from a French center for newborn screening.

Objectives: Newborn screening (NBS) for ß-thalassemia is based on measuring the expression of the hemoglobin A (HbA) fraction. An absence or very low level of HbA at birth may indicate ß-thalassemia. The difficulty is that the HbA fraction at birth is correlated with gestational age (GA) and highly variable between individuals. We used HbA expressed in multiples of the normal (MoM) to evaluate relevant thresholds for NBS of ß-thalassemia. Methods: The chosen threshold (HbA≤0.25 MoM) was prospectively applied for 32 months in our regional NBS program for sickle cell disease, for all tests performed, to identify patients at risk of ß-thalassemia. Reliability of this threshold was evaluated at the end of the study. Results: In all, 343,036 newborns were tested, and 84 suspected cases of ß-thalassemia were detected by applying the threshold of HbA≤0.25 MoM. Among the n=64 cases with confirmatory tests, 14 were confirmed using molecular analysis as ß-thalassemia diseases, 37 were confirmed as ß-thalassemia trait and 13 were false-positive. Determination of the optimum threshold for ß-thalassemia screening showed that HbA≤0.16 MoM had a sensitivity of 100% and a specificity of 95.3%, whatever the GA. Conclusions: NBS for ß-thalassemia diseases is effective, regardless of the birth term, using the single robust threshold of HbA≤0.16 MoM. A higher threshold would also allow screening for carriers, which could be interesting when ß-thalassemia constitutes a public health problem.

Isolated congenital asplenia: a French nationwide retrospective survey of 20 cases.

OBJECTIVE: To better describe the natural history, mode of inheritance, and the epidemiological and clinical features of isolated congenital asplenia, a rare and poorly understood primary immunodeficiency. STUDY DESIGN: A French national retrospective survey was conducted in hospital pediatric departments. A definitive diagnosis of ICA was based on the presence of Howell-Jolly bodies, a lack of detectable spleen, and no detectable cardiovascular malformation. RESULTS: The study included 20 patients (12 males and 8 females) from 10 kindreds neither related to each other nor consanguineous. The diagnosis of ICA was certain in 13 cases (65%) and probable in 7 cases (35%). Ten index cases led to diagnosis of 10 additional cases in relatives. Five cases were sporadic and 15 were familial, suggesting autosomal dominant inheritance. Median age was 12 months at first infection (range, 2-516 months), 11 months at diagnosis of asplenia (range, 0-510 months), and 9.9 years at last follow-up (range, 0.7-52 years). Fifteen patients sustained 18 episodes of invasive bacterial infection, caused mainly by Streptococcus pneumoniae (61%). Outcomes were poor, with 9 patients (45%) dying from fulminant infection. CONCLUSIONS: ICA is more common than was previously thought, with an autosomal dominant inheritance in at least some kindreds. Relatives of cases of ICA should be evaluated for ICA, as should children and young adults with invasive infection.

Management and successful desensitization in methotrexate-induced anaphylaxis.

Anaphylactic/anaphylactoid reactions to methotrexate are rare. In patients with methotrexate-induced anaphylaxis, discontinuation of treatment may increase the risk of death due to cancer progression. In such patients, desensitization may enable the patient to continue treatment with methotrexate. We report the case of a child with metastatic osteosarcoma, who experienced an anaphylactic/anaphylactoid reaction to methotrexate. Skin tests with methotrexate were not performed because their diagnostic value is controversial. Desensitization with methotrexate was successful and allowed the patient to complete 12 additional courses of chemotherapy. Thus, we confirm that desensitization may be a safe procedure in patients with cancer who experience methotrexate-induced anaphylaxis.

Assessment of blood enterovirus PCR testing in paediatric populations with fever without source, sepsis-like disease, or suspected meningitis: a prospective, multicentre, observational cohort study.

BACKGROUND: Enteroviruses are the most frequent cause of acute meningitis and are seen increasingly in sepsis-like disease and fever without source in the paediatric population. Detection of enterovirus in cerebrospinal fluid (CSF) specimens by PCR is the gold standard diagnostic test. Our aim was to assess a method of detecting enterovirus in blood specimens by PCR. METHODS: We did a prospective, multicentre, observational study at 35 French paediatric and emergency departments in 16 hospitals. We recruited newborn babies (aged ≤28 days) and infants (aged >28 days to ≤2 years) with fever without source, sepsis-like disease, or suspected meningitis, and children (aged >2 years to ≤16 years) with suspected meningitis, who were admitted to a participating hospital. We used a standardised form to obtain demographic, clinical, and laboratory data, which were anonymised. Enterovirus PCR testing was done in blood and CSF specimens. FINDINGS: Between June 1, 2015, and Oct 31, 2015, and between June 1, 2016, and Oct 31, 2016, we enrolled 822 patients, of whom 672 had enterovirus PCR testing done in blood and CSF specimens. Enterovirus was detected in 317 (47%) patients in either blood or CSF, or both (71 newborn babies, 83 infants, and 163 children). Detection of enterovirus was more frequent in blood samples than in CSF specimens of newborn babies (70 [99%] of 71 vs 62 [87%] of 71; p=0·011) and infants (76 [92%] of 83 vs 62 [75%] of 83; p=0·008), and was less frequent in blood samples than in CSF specimens of children (90 [55%] of 163 vs 148 [91%] of 163; p<0·0001). Detection of enterovirus was more frequent in blood samples than in CSF specimens of infants aged 2 years or younger with fever without source (55 [100%] of 55 vs 41 [75%] of 55; p=0·0002) or with sepsis-like disease (16 [100%] of 16 vs nine [56%] of 16; p=0·008). Detection of enterovirus was less frequent in blood than in CSF of patients with suspected meningitis (165 [67%] of 246 vs 222 [90%] of 246; p<0·0001). INTERPRETATION: Testing for enterovirus in blood by PCR should be an integral part of clinical practice guidelines for infants aged 2 years or younger. This testing could decrease the length of hospital stay and reduce exposure to antibiotics for low-risk patients admitted to the emergency department with febrile illness. FUNDING: University Hospital Clermont-Ferrand.