Hemolytic uremic syndrome in the setting of COVID-19 successfully treated with complement inhibition therapy: An instructive case report of a previously healthy toddler and review of literature.

Introduction: As the global pandemic continues, new complications of COVID-19 in pediatric population have turned up, one of them being hemolytic uremic syndrome (HUS), a complement-mediated thrombotic microangiopathy (CM-TMA) characterized by triad of thrombocytopenia, microangiopathic hemolytic anemia and acute kidney injury (AKI). With both multisystem inflammatory syndrome in children (MIS-C) and HUS sharing complement dysregulation as one of the key factors, the aim of this case report is to highlight differences between these two conditions and also emphasize the importance of complement blockade as a treatment modality. Case report: We describe a 21-month-old toddler who initially presented with fever and confirmed COVID-19. His condition quickly deteriorated and he developed oliguria, accompanied with diarrhea, vomiting and oral intake intolerance. HUS was suspected, supported with compelling laboratory findings, including decreased platelets count and C3 levels, elevated LDH, urea, serum creatinine and sC5b-9 and presence of schistocytes in peripheral blood, negative fecal Shiga toxin and normal ADAMTS13 metalloprotease activity. The patient was given C5 complement blocker Ravulizumab and started to display rapid improvement. Conclusion: Although reports of HUS in the setting of COVID-19 continue to pour in, the questions of exact mechanism and similarities to MIS-C remain. Our case for the first time accentuates the use of complement blockade as a valuable treatment option in this scenario. We sincerely believe that reporting on HUS as a complication of COVID-19 in children will give rise to improved diagnosis and treatment, as well as better understanding of both of these intricating diseases.

The prevalence of muscular dystrophy and spinal muscular atrophy in Croatia: data from national and non-governmental organization registries.

AIM: To determine the prevalence of muscular dystrophy (MD) and spinal muscular atrophy (SMA) in Croatia by use of multiple epidemiological tools. METHODS: This epidemiological study collected data from three national patient registries and one database of a non-governmental organization (NGO) of MD and SMA patients. The study involved all individuals who either had undergone hospital treatment for MD or SMA, had consulted their primary health care providers for MD- and SMA-related symptoms, were listed as disabled due to MD or SMA, or were members of the mentioned NGO in 2016. In order to prevent double entries, we created a new database of all living individuals, each with a unique identification number. The prevalence rates for 2016 were calculated by age and sex groups. RESULTS: There were 926 patients diagnosed with MD (544 men). Most men diagnosed with MD were in the age group 10-19, whereas most women were in the age group 50-59. MD prevalence in Croatia was 22.2 per 100000 population. There were 392 patients diagnosed with SMA (198 men). Most men with SMA were in the age group 50-59, whereas most women were in the age group 60-69. SMA prevalence in Croatia was 9.3 per 100000 population. CONCLUSION: SMA prevalence rate in Croatia is similar to SMA prevalence worldwide. However, MD prevalence rate is higher than worldwide estimates. This difference could be attributed to the fact that we could not confirm whether every patient registered in these databases actually met the diagnostic criteria for MD and SMA.