Use of Eculizumab in Pediatric Patients with High-Risk Transplantation-Associated Thrombotic Microangiopathy: Outcomes and Risk Factors Associated with Response and Survival. A Retrospective Study on Behalf of the Spanish Group for Hematopoietic Transplantation and Cellular Therapy (GETH-TC).

Transplantation-associated thrombotic microangiopathy (TA-TMA) is associated with high morbidity and mortality. Although survival has improved significantly with the introduction of eculizumab, the need for improvement remains, especially in high-risk patients. This study aimed to describe the results obtained with eculizumab in a pediatric cohort with the attempt to define which risk factors could determine the response to treatment. We designed a national multicenter retrospective study of children treated with eculizumab for high-risk TA-TMA. The study cohort comprised 29 patients who had undergone a first (n = 28) or second (n = 1) allogeneic hematopoietic stem cell transplantation (HSCT) for malignant (n = 17) or nonmalignant (n = 12) disease. The median time from HSCT to TA-TMA diagnosis was 154 days (interquartile range [IQR], 103 to 263 days). Eleven patients (38%) who were initially diagnosed with low- to intermediate-risk TA-TMA progressed to high-risk TA-TMA (hrTA-TMA), within a median time of 4 days (IQR, 1 to 33 days). SC5b-9 was increased in 90% of 20 patients in whom it was measured. Renal (n = 12), pulmonary (n = 1), and intestinal (n = 1) biopsy confirmed the diagnosis in 12 of 14 patients (85%). Seventeen patients (58%) had extrarenal involvement with serositis (n = 13; 44,8%), pulmonary (n = 12; 41,4%), gastrointestinal (n = 8; 27.6%), cardiovascular (n = 7; 24.1%), or central nervous system (CNS) (n = 2; 6.9%) involvement. The median time from hrTA-TMA diagnosis to the initiation of eculizumab was 7 days (IQR, 1 to 8 days). Overall, 19 patients (65.5%) responded to eculizumab, of whom 17 (58.6%) achieved a complete response and 2 (6.9%) achieved a partial response. The remaining 10 patients (34.5%) did not show any of response. The overall response rate to eculizumab for TA-TMA was 27.59% (95% confidence interval [CI], 14.87% to 47.66%) at 1 month, 55.17% (95% CI, 38.43% to 73.48%) at 3 months, and 62.07% (95% CI, 45.10% to 79.13%) at 6 months after eculizumab initiation. In multivariate analysis, the pulmonary involvement decreased the probability of response (hazard ratio [HR], .18; P = .0298). The 1-year overall survival (OS) was 55.2% (95% CI, 35.6% to 71.0%) for the whole cohort and 83.3% (95% CI, 56.7% to 94.3%) for patients who responded to eculizumab. Pulmonary involvement (HR, 14.93; P = .0043) and CNS involvement (HR, 8.63; P = .0497) were associated with a statistically significant decrease in survival. We found that patients diagnosed with hrTA-TMA with pulmonary involvement had a poor response to eculizumab, and that patients with pulmonary and CNS involvement had significantly decreased survival. Given these results, we hypothesize that providing eculizumab therapy at an early stage of the disease before organ damage is established might significantly improve the response and, consequently, survival.

Changes in the epidemiology of invasive fungal disease in a Pediatric Hematology and Oncology Unit: the relevance of breakthrough infections.

BACKGROUND: Invasive fungal disease (IFD) is a significant cause of morbimortality in children under chemotherapy or hematopoietic stem cell transplant (HSCT). The purpose of this study is to describe the changes in the IFD epidemiology that occurred in a Pediatric Hematology-Oncology Unit (PHOU) with an increasing activity over time. METHODS: Retrospective revision of the medical records of children (from 6 months to 18 years old) diagnosed with IFD in the PHOU of a tertiary hospital in Madrid (Spain), between 2006 and 2019. IFD definitions were performed according to the EORTC revised criteria. Prevalence, epidemiological, diagnostic and therapeutic parameters were described. Comparative analyses were conducted using Chi-square, Mann-Whitney and Kruskal-Wallis tests, according to three time periods, the type of infection (yeast vs mold infections) and the outcome. RESULTS: Twenty-eight episodes of IFD occurred in 27 out of 471 children at risk (50% males; median age of 9.8 years old, [IQR 4.9-15.1]), resulting in an overall global prevalence of 5.9%. Five episodes of candidemia and 23 bronchopulmonary mold diseases were registered. Six (21.4%), eight (28.6%) and 14 (50%) episodes met criteria for proven, probable and possible IFD, respectively. 71.4% of patients had a breakthrough infection, 28.6% required intensive care and 21.4% died during treatment. Over time, bronchopulmonary mold infections and breakthrough IFD increased (p=0.002 and p=0.012, respectively), occurring in children with more IFD host factors (p=0.028) and high-risk underlying disorders (p=0.012). A 64% increase in the number of admissions in the PHOU (p<0.001) and a 277% increase in the number of HSCT (p=0.008) were not followed by rising rates of mortality or IFD/1000 admissions (p=0.674). CONCLUSIONS: In this study, we found that yeast infections decreased, while mold infections increased over time, being most of them breakthrough infections. These changes are probably related to the rising activity in our PHOU and an increase in the complexity of the baseline pathologies of patients. Fortunately, these facts were not followed by an increase in IFD prevalence or mortality rates.

Risk-score based strategy to minimize antibiotic exposure in children with sickle cell disease and fever.

Severe bacterial infections (SBI) have become less frequent in children with sickle cell disease (SCD) in the last decades. However, because of their potential risk of SBI, they usually receive empirical therapy with broad-spectrum antibiotics when they develop fever and are hospitalized in many cases. We performed a prospective study including 79 SCD patients with fever [median age 4.1 (1.7-7.5) years, 78.5% males; 17 of the episodes were diagnosed with SBI and 4 of them were confirmed] and developed a risk score for the prediction of SBI. The optimal score included CRP > 3 mg/dl, IL-6 > 125 pg/ml and hypoxemia, with an AUC of 0.91 (0.83-0.96) for the prediction of confirmed SBI and 0.86 (0.77-0.93) for possible SBI. We classified the patients in 3 groups: low, intermediate and high risk of SBI. Our risk-score-based management proposal could help to safely minimize antibiotic treatments and hospital admissions in children with SCD at low risk of SBI.

Interleukin 6 as a marker of severe bacterial infection in children with sickle cell disease and fever: a case-control study.

BACKGROUND: Etiological diagnosis of fever in children with sickle cell disease (SCD) is often challenging. The aim of this study was to analyze the pattern of inflammatory biomarkers in SCD febrile children and controls, in order to determine predictors of severe bacterial infection (SBI). METHODS: A prospective, case-control study was carried out during 3 years, including patients younger than 18 years with SCD and fever (cases) and asymptomatic steady-state SCD children (controls). Clinical characteristics and laboratory parameters, including 10 serum proinflammatory cytokines (IL-1ß, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-17a, IFN-γ and TNF-α) and comparisons among study subgroups were analyzed. RESULTS: A total of 137 patients (79 cases and 58 controls) were included in the study; 78.5% males, median age 4.1 (1.7-7.5) years. Four cases were diagnosed with SBI, 41 viral infection (VI), 33 no proven infection (NPI) and 1 bacterial-viral coinfection (the latter excluded from the subanalyses). IL-6 was significantly higher in patients with SBI than in patients with VI or NPI (163 vs 0.7 vs 0.7 pg/ml, p < 0.001), and undetectable in all controls. The rest of the cytokines analyzed did not show any significant difference. The optimal cut-off value of IL-6 for the diagnosis of SBI was 125 pg/mL, with high PPV and NPV (PPV of 100% for a prevalence rate of 5, 10 and 15% and NPV of 98.7%, 97.3% and 95.8% for those prevalences rates, respectively). CONCLUSION: We found that IL-6 (with a cut-off value of 125 pg/ml) was an optimal marker for SBI in this cohort of febrile SCD children, with high PPV and NPV. Therefore, given its rapid elevation, IL-6 may be useful to early discriminate SCD children at risk of SBI, in order to guide their management.

Optimised molecular genetic diagnostics of Fanconi anaemia by whole exome sequencing and functional studies.

PURPOSE: Patients with Fanconi anaemia (FA), a rare DNA repair genetic disease, exhibit chromosome fragility, bone marrow failure, malformations and cancer susceptibility. FA molecular diagnosis is challenging since FA is caused by point mutations and large deletions in 22 genes following three heritability patterns. To optimise FA patients' characterisation, we developed a simplified but effective methodology based on whole exome sequencing (WES) and functional studies. METHODS: 68 patients with FA were analysed by commercial WES services. Copy number variations were evaluated by sequencing data analysis with RStudio. To test FANCA missense variants, wt FANCA cDNA was cloned and variants were introduced by site-directed mutagenesis. Vectors were then tested for their ability to complement DNA repair defects of a FANCA-KO human cell line generated by TALEN technologies. RESULTS: We identified 93.3% of mutated alleles including large deletions. We determined the pathogenicity of three FANCA missense variants and demonstrated that two FANCA variants reported in mutations databases as 'affecting functions' are SNPs. Deep analysis of sequencing data revealed patients' true mutations, highlighting the importance of functional analysis. In one patient, no pathogenic variant could be identified in any of the 22 known FA genes, and in seven patients, only one deleterious variant could be identified (three patients each with FANCA and FANCD2 and one patient with FANCE mutations) CONCLUSION: WES and proper bioinformatics analysis are sufficient to effectively characterise patients with FA regardless of the rarity of their complementation group, type of mutations, mosaic condition and DNA source.

Kaposiform Hemangioendothelioma Presenting as Hydrops Fetalis.

We describe the case of a 33-week preterm infant who developed nonimmune hydrops fetalis secondary to a kaposiform hemangioendothelioma (KHE). The tumor was successfully treated with vincristine, prednisone, ticlopidine, and aspirin. KHE can be an unusual cause of hydrops fetalis; in such cases, diagnosis can be challenging since generalized edema can obscure KHE.