Introduction Etiological diagnosis of fever in sickle cell disease (SCD) children is often challenging. Objective: to analyze the pattern of inflammatory biomarkers in SCD febrile children and controls, in order to determine predictors of severe bacterial infection (SBI). Methods Prospective, case-control study of febrile and steady-state SCD children carried out during 3 years. Clinical characteristics and laboratory parameters, including 10 serum proinflammatory cytokines (IL-1β, 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 (78 cases and 59 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) and 33 no proven infection (NPI). 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 of 5, 10 and 15% and NPV of 98.7%, 97.3% and 95.8% for those prevalences, respectively). Conclusion We found that IL-6 (optimal cut-off value of 125 pg/ml) was a very good marker for SBI in this cohort of febrile SCD children, with high PPV and NPV. Therefore, IL-6 may be useful, alone or combined with other biomarkers, to guide the management of these patients.

BACKGROUND The use of azoles for antifungal prophylaxis after familial allogeneic stem cell transplantation in children (SCT) is hindered by adverse events and drug interactions especially in children affected by sickle cell disease. Intermittent, higher dose of micafungin could be an alternative. METHODS A prospective, observational, longitudinal, single-center study was conducted between May 2015 and June 2018. The study included 30 patients between 2 and 18 years old who underwent allogeneic SCT and received prophylaxis with micafungin on alternating days after the bone marrow engraftment phase. FINDINGS Fifty transplants performed, 30 included prophylaxis against IFIs, with micafungin in an alternating pattern according to the previously described protocol. The indication for HSCT was hemoglobinopathies in 76.7%, acute leukemia in 20.0% and Fanconi anemia in 3.3%. The prophylaxis duration was 2.33 months (1.53 to 3.98). In our study, 40.0% (12/30) of the patients had acute GVHD, and 6.7% (2/30) had chronic GVHD, which prolonged the duration of alternating prophylaxis. No serious adverse effects of the use of micafungin were observed in any of the patients. There was also no breakthrough Invasive fungal infection (IFI) during alternating prophylaxis. CONCLUSION: In selected patients, micafungin was well tolerated without breakthrough IFI in our study.