Exposure to inorganic particles in paediatric sarcoidosis: the PEDIASARC study.

Inorganic antigens may contribute to paediatric sarcoidosis. Thirty-six patients matched with 36 healthy controls as well as a group of 21 sickle-cell disease (SCD) controls answered an environmental questionnaire. Patients' indirect exposure to inorganic particles, through coresidents' occupations, was higher than in healthy and SCD controls (median score: 2.5 (0.5-7) vs 0.5 (0-2), p=0.003 and 1 (0-2), p=0.012, respectively), especially for construction, exposures to metal dust, talc, abrasive reagents and scouring products. Wood or fossil energies heating were also linked to paediatric sarcoidosis. This study supports a link between mineral environmental exposure due to adult coresident occupations and paediatric sarcoidosis.

Deficient mitophagy pathways in sickle cell disease.

Sickle cell disease (SCD) is characterised by chronic haemolysis and oxidative stress. Herein, we investigated 30 SCD patients and found 40% with elevated mitochondria levels (SS-mito+ ) in their mature red blood cells, while 60% exhibit similar mitochondria levels compared to the AA group (SS-mito- ). The SS-mito+ patients are characterised by higher reticulocytosis and total bilirubin levels, lower foetal haemoglobin, and non-functional mitochondria. Interestingly, we demonstrated decreased levels of mitophagy inducers, PINK1 and NIX, and higher levels of HSP90 chaperone in their red cells. Our results highlighted for the first time an abnormal retention of mitochondria in SCD linked with mitophagy-related proteins.

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.

Implications of a paediatrician-psychologist tandem for sickle cell disease care and impact on cognitive functioning.

Sickle cell disease (SCD), a life-threatening chronic disease, necessitates a paediatric treatment plan that considers the influence of psychological, family and intercultural factors. At the Louis-Mourier Hospital (APHP) in Colombes, France, we introduced an original paediatric-psychological partnership where a clinical psychologist accompanies the paediatrician at programmed consultations. We evaluated children and their parents treated in Colombes and in two other paediatric units using standardized culture-free tools and clinical interviews to evaluate the psychological repercussions of SCD. We first present a global view of the different ways that SCD affects both children and their families. We then discuss findings from a study evaluating the overall efficacy of an integrated psycho-medical treatment model as compared to the usual medical care model. Children in the integrated care model improved their cognitive functioning assessed using the Rey-Osterrieth complex figure test compared to treatment as usual. CONCLUSION: Findings suggest that the concept of a "partnership practice" can improve children's ability to grapple with SCD and is a promising approach for long-term care of SCD. What is Known: • Painful crises of sickle cell disease are unpredictable and appear in early childhood • Stress as well as the complex psychological and intercultural issues associated with SCD may aggravate the children's symptoms • Standard pediatric care and research deal primarily with medical issues What is New: • Evidence-based research examining the psychological repercussions of SCD in pediatric treatment as well as the parental distress • First study using standardized culture-free tools • Cognitive functioning improves under an innovative "partnership" model.

Tuberculosis in children with sickle cell anaemia: a retrospective study in French tertiary care centres.

Tuberculosis (TB) and sickle cell anaemia (SCA) may affect the same population of patients, particularly in Africa but also in high-TB incidence areas in developed countries. However, few data are available from children with SCA who develop TB. The aim of this study was to describe the clinical features and outcome of TB diagnosed in children with SCA. We conducted a retrospective, descriptive study in three referral centre of Sickle Cell Disease in Paris, France. We included 11 patients with SCA who develop TB. The median age at TB diagnosis was 11 years [7.5-14.5]. Two patients were asymptomatic and nine patients were symptomatic. Six patients had pulmonary TB (pulmonary, pleural and mediastinal lesions). Five patients had extrapulmonary TB (osteoarticular TB, hepatic TB, cervical and mediastinal TB). Mycobacterium tuberculosis was isolated in four of the 11 cases. All patients recovered after a median of 6 months of anti-TB treatment. The localisation of TB and outcome after treatment in our SCA patients were similar to the one observed in an age-and sex-matched control group of non-SCA patient with TB. CONCLUSION: despite the low number of patients included in our study, SCA does not seem to be a risk factor for severe TB. What is Known: • Tuberculosis (TB) remains a global health problem particularly in developing countries, and Sickle cell anaemia (SCA) is currently one of the most common genetic diseases in the world that mainly affects African populations. • Very few data are available on TB in SCA patients. What is New: • The features of TB in children with SCA seem to be comparable to those expected in general population, with favourable outcomes in response to standard treatment. • Monitoring the dosage of anti-TB treatments could be of interest because of the possible impact of SCA on drug metabolism.

Improvement of medical care in a cohort of newborns with sickle-cell disease in North Paris: impact of national guidelines.

We conducted a retrospective study on newborns with sickle-cell disease (SCD), born 1995-2009, followed in a multicentre hospital-based network. We assessed patient outcomes, medical care and compliance with the national guidelines published in December 2005. Data from 1033 patients (742 SS/Sß°-thalassaemia) with 6776 patient-years of follow-up were analysed (mean age 7·1 ± 3·9 years). SCD-related deaths (n = 13) occurred only in SS-genotype patients at a median age of 23·1 months, mainly due to acute anaemia (n = 5, including 2 acute splenic sequestrations) and infection (n = 3). Treatment non-compliance was associated with a 10-fold higher risk of SCD-related death (P = 0·01). Therapeutic intensification was provided for all stroke patients (n = 12), almost all patients with abnormal transcranial Doppler (TCD) (n = 76) or with >1 acute chest syndrome/lifetime (n = 64) and/or ≥3 severe vaso-occlusive crises/year (n = 100). Only 2/3 of patients with baseline haemoglobin <70 g/l received intensification, mainly for other severity criteria. Overall, hydroxycarbamide was under-prescribed, given to 2/3 of severe vaso-occlusive patients and 1/3 of severely anaemic patients. Nevertheless, introduction of the on-line guidelines was concomitant with an improvement in medical care in the 2006-2009 cohort with a trend towards increased survival at 5 years, from 98·3% to 99·2%, significantly increased TCD coverage (P = 0·004) and earlier initiation of intensification of therapy (P ≤ 0·01).

Predictors of health-related quality of life in a large cohort of adult patients living with sickle cell disease in France: the DREPAtient study.

Background: Sickle cell disease (SCD) is an inherited autosomal recessive disorder exhibiting a range of symptoms and acute and/or chronic complications that affect the quality of life. This study aimed to assess health-related quality of life (HRQoL) and to identify the associated factors in adult patients with SCD in France. Methods: DREPAtient is a cross-sectional, multicenter study conducted from June 2020 to April 2021 in France and in certain French overseas territories where SCD is highly prevalent. Sociodemographic and clinical data were collected online. HRQoL was assessed by the French version of the 36-Item Short Form Survey (SF-36) questionnaire. HRQoL determinants were identified using multivariable linear regression analysis. Results: In total, 570 participants were included, mostly women (68.9%), with a mean age of 33.3 (±10.7) years. The highest mean score HRQoL was found in the Physical functioning domain (67.5 ± 21.8) and the lowest mean score in the General Health perception domain (37.7 ± 20.3). The mean score of the physical composite (PCS) and mental composite (MCS) of SF-36 summary scores was 40.6 ± 8.9 and 45.3 ± 9.8, respectively. Participants receiving oxygen therapy (ß = -3.20 [95%CI: -5.56; -0.85]), those with a history of femoral osteonecrosis (-3.09 [-4.64; -1.53]), those hospitalized for vaso-occlusive crisis (VOC) or acute chest syndrome (ACS) (-2.58 [-3.93; -1.22]), those with chronic complications (-2.33 [-4.04; -0.62]), female participants (-2.17 [-3.65; -0.69]), those with psychological follow-up (-2.13 [-3.59; -0.67]), older participants (-1.69 [-3.28; -0.09]), and those receiving painkillers (-1.61 [-3.16; -0.06]) reported worse PCS score. By contrast, those who had completed secondary or high school (4.36 [2.41; 6.31]) and those with stable financial situation (2.85 [0.94, 4.76]) reported better PCS scores. Worse MCS scores were reported among participants with psychological follow-up (-2.54 [-4.28; -0.80]) and those hospitalized for VOC/ACS in the last 12 months (-2.38 [-3.99; -0.77]), while those who had relatives' support (5.27 [1.92; 8.62]) and those with stable financial situation (4.95 [2.65; 7.26]) reported better MCS scores. Conclusion: Adults with major SCD reported poor physical and mental HRQoL scores. Hospitalization for VOC/ACS, chronic complications, use of painkillers, perceived financial situation, and support from relatives are important predictors of HRQoL in SCD patients. Interventions to improve HRQoL outcomes SCD should be considered.

Fetal hemoglobin and hydroxycarbamide moduate both plasma concentration and cellular origin of circulating microparticles in sickle cell anemia children.

Microparticles are cell membrane-derived microvesicles released during cell apoptosis and activation processes. They have been described as bio-markers in various vascular diseases, including sickle cell anemia, and associated with an increased risk of thrombosis. We investigated the effects of fetal hemoglobin level, a factor known to modulate the clinical expression of sickle cell anemia, and that of hydroxycarbamide treatment which reduces the frequency of vasoocclusive crises, the canonical clinical manifestation of the disease, on both the plasma concentration and the cellular origin of circulating microparticles. Flow cytometry was used to characterize microparticles in 62 sickle cell anemia children at steady state aged 2 months-16 years; 13 of them were treated with hydroxycarbamide. In untreated children, we observed negative correlations between fetal hemoglobin levels and the absolute plasma concentration of microparticles as well as that of microparticles specifically derived from platelets, erythrocytes, and monocytes. Compared to untreated children, those treated with hydroxyurea showed lower concentrations of total microparticles as a consequence of decreased microparticles shed by platelets and erythrocytes. In conclusion, in our sickle cell patients, neonatal decline of fetal hemoglobin coincided with an increase in circulating microparticles derived from erythrocytes, platelets, and monocytes. Hydroxyurea treatment was associated with a decrease in microparticles derived from erythrocytes and platelets.

Invasive Bacterial Infections in Children With Sickle Cell Disease: 2014-2019.

BACKGROUND: Children with sickle cell disease (SCD) are at a high risk of invasive bacterial infections (IBI). Universal penicillin prophylaxis and vaccination, especially against Streptococcus pneumoniae, have deeply changed its epidemiology. Analysis of IBI in children with SCD in a post-13-valent pneumococcal vaccine era is limited. METHODS: Twenty-eight pediatric hospitals from 5 European countries retrospectively collected IBI episodes in SCD children aged 1 month to 18 years between 2014 and 2019. IBI was defined as a positive bacterial culture or polymerase chain reaction from a normally sterile fluid: blood, cerebrospinal, joint, or pleural fluid and deep surgical specimen. RESULTS: We recorded 169 IBI episodes. Salmonella spp. was the main isolated bacteria (n = 44, 26%), followed by Streptococcus pneumonia (Sp; n = 31, 18%) and Staphylococcus aureus (n = 20, 12%). Salmonella prevailed in osteoarticular infections and in primary bacteremia (45% and 23% of episodes, respectively) and Sp in meningitis and acute chest syndrome (88% and 50%, respectively). All Sp IBI occurred in children ≤10 years old, including 35% in children 5 to 10 years old. Twenty-seven (17%) children had complications of infection and 3 died: 2 because of Sp, and 1 because of Salmonella. The main risk factors for a severe IBI were a previous IBI and pneumococcal infection (17 Sp/51 cases). CONCLUSIONS: In a post-13-valent pneumococcal vaccine era, Salmonella was the leading cause of bacteremia in IBI in children with SCD in Europe. Sp came second, was isolated in children ≤10 years old, and was more likely to cause severe and fatal cases.

Acute splenic sequestration crisis in sickle cell disease: cohort study of 190 paediatric patients.

Acute splenic sequestration crisis (ASSC) is an unpredictable life-threatening complication of sickle cell disease (SCD) in infants. Here, our objective was to update available clinical information on ASSC. We retrospectively studied the 190 patients who were diagnosed at birth with SS or Sbeta(0) in the Paris conurbation between 2000 and 2009 and who experienced ASSC. They had 437 ASSC episodes (0.06/patient-year). Median age at the first episode was 1.4 years (0.1-7) and 67% of patients had more than one episode. Age was the only factor predicting recurrence: the risk was lower when the first episode occurred after 2 years versus before 1 year of age (hazard ratio, 0.60; 95% confidence interval, 0.41-0.88; P=0.025). A concomitant clinical event was found in 57% of episodes. The mortality rate was 0.53%. The treatment consisted in watchful waiting without prophylactic blood transfusions or splenectomy in 103 (54%) patients and in a blood transfusion programme in 55 (29%) patients. Overall, splenectomy was performed in 71 (37%) patients, at a median age of 4.5 years (range, 1.9-9.4). In conclusion, aggressive treatment may be warranted in patients experiencing ASSC before 2 years of age. Randomized controlled trials are needed to define the best treatment modalities.

Procalcitonin at 12-36 hours of fever for prediction of invasive bacterial infections in hospitalized febrile neonates.

Aim: We aimed to investigate the performance of procalcitonin (PCT) assay between 12 and 36 h after onset of fever (PCT H12-H36) to predict invasive bacterial infection (IBI) (ie, meningitis and/or bacteremia) in febrile neonates. Methods: We retrospectively included all febrile neonates hospitalized in the general pediatric department in a teaching hospital from January 2013 to December 2019. PCT assay ≤ 0.6 ng/ml was defined as negative. The primary outcome was to study the performance of PCT H12-H36 to predict IBI. Results: Out of 385 included neonates, IBI was ascertainable for 357 neonates (92.7%). We found 16 IBI: 3 meningitis and 13 bacteremia. Sensitivity and specificity of PCT H12-H36 in the identification of IBI were, respectively, 100% [95% CI 82.9-100%] and 71.8% [95% CI 66.8-76.6%], with positive and negative predictive values of 14.3% [95% CI 8.4-22.2%] and 100% [95% CI 98.8-100%] respectively. Of the 259 neonates who had a PCT assay within the first 12 h of fever (< H12) and a PCT assay after H12-H36, 8 had IBI. Two of these 8 neonates had a negative < H12 PCT but a positive H12-H36 PCT. Conclusions: PCT H12-H36 did not miss any IBI whereas < H12 PCT could missed IBI diagnoses. PCT H12-H36 might be included in clinical decision rule to help physicians to stop early antibiotics in febrile neonates.

Pathophysiological insights in sickle cell disease.

The first coherent pathophysiological scheme for sickle cell disease (SCD) emerged in the sixties-seventies based on an extremely detailed description of the molecular mechanism by which HbS in its deoxy-form polymerises and forms long fibres within the red blood cell that deform it and make it fragile. This scheme explains the haemolytic anaemia, and the mechanistic aspects of the vaso-occlusive crises (VOCs), but, even though it constitutes the basic mechanism of the disease, it does not account for the processes that actually trigger VOCs. This paper reviews recent data which imply: red blood cell dehydration, its abnormal adhesion properties to the endothelium, the participation of inflammatory phenomenon and of a global activation of all the cells present in the vessel, and finally, abnormalities of the vascular tone and of nitric oxide metabolism. These data altogether have shed a new light on the pathophysiology of the first molecular disease i.e. sickle cell disease.

Tolerance and humoral immune response to the yellow fever vaccine in sickle cell disease children treated with hydroxyurea: a multicentre prospective study.

BACKGROUND: Sickle cell disease (SCD) children are frequent travellers to countries where yellow fever (YF) is endemic, but there are no data regarding the safety and immunogenicity of the vaccine in such children treated with hydroxyurea (HU). The main objective of this study was to compare the tolerance and immune response to YF vaccination in SCD children treated or not with HU. METHOD: SCD children < 18 years attending the international travel clinics of three large paediatric centres and requiring a first YF vaccination were included in a prospective study. Adverse events were collected 2 weeks after vaccination. YF vaccine antibody titres were measured ~6 months after vaccination. RESULTS: Among the 52 SCD children vaccinated against YF, 17 (33%) were treated with HU. Only mild adverse events, mainly fever and local reaction, were observed in the HU group with a similar frequency in the non-HU group (57 and 35%, respectively, P = 0.30). YF antibody titres were measured in 15/17 patients in the HU group and 23/35 patients in the non-HU group after a median of 6.0 months (3.5-8.5) following vaccination. The geometric mean of YF antibody titre was similar in both groups. A protective antibody level was observed in 85% of the children in the HU group vs 100% in the non-HU group (P = 0.14), suggesting a lower effectiveness of the vaccine in patients on HU similarly to what has been described in patients on immune suppressive therapy for other vaccines. CONCLUSION: YF vaccination seems to be safe and efficient in SCD children treated with HU. Considering the potential risk of severe complications in cases of YF while travelling in Africa for those patients, the benefit-to-risk ratio argues for YF vaccination in all SCD children. Control of a protective antibody titre may also be useful to ascertain an adequate response in those treated with HU.