Cardiac involvement in pediatric hemolytic uremic syndrome

Haemolytic uremic syndrome as a cause of chronic kidney disease stage 5 in children is in retreat: results from the Polish Registry of Kidney Replacement Therapy in children (2000-2023)

BACKGROUND

Haemolytic uremic syndrome (HUS) is a life-threatening disease with a historically poor prognosis in children receiving maintenance kidney replacement therapy (KRT). This study aimed to analyse the incidence and outcome of chronic kidney disease stage 5 (CKD5) due to Escherichia coli-HUS (STEC-HUS) and complement-mediated HUS (CM-HUS) in children, compared with controls with non-HUS CKD5 over the last 24 years.

METHODS

The study included 1488 children undergoing KRT in Poland between 2000 and 2023. Thirty-nine patients with CM-HUS and 18 with STEC-HUS were identified and analysed for incidence, KRT modality and survival.

RESULTS

The incidence rate of CKD5 was 0.09 cases/million age-related population (marp) for STEC-HUS and 0.23/marp for CM-HUS, while no new cases have been observed in recent years. CKD5 due to CM-HUS developed significantly earlier from initial HUS manifestation than in STEC-HUS (median 0.2 vs. 9.8 years). CM-HUS was associated with younger age at initiation of KRT compared to STEC-HUS and non-HUS controls (median 6.0 years vs. 10.9 and 10.9 years), with higher risk of death (Hazard Ratio 1.92, 95% confidence interval 0.9-4.13) and worse 5-year kidney graft survival at 77%, 93% and 90%, respectively (p < 0.001).

CONCLUSIONS

In recent years, both CM-HUS and STEC-HUS have become increasingly rare causes of CKD5 in children. CKD5 due to CM-HUS in the eculizumab era and due to STEC-HUS after improving supportive treatment is exceptional. Children on KRT due to STEC-HUS had a significantly better survival, shorter waiting time for kidney transplantation and better kidney graft survival compared to the CM-HUS group.

Thrombotic microangiopathies in critically ill children: The MATUCIP registry in Spain

INTRODUCTION

Thrombotic microangiopathies (TMA) are rare diseases usually presenting with renal, haematological, neurologic and cardiovascular involvement and nonspecific but severe symptoms. A registry of TMA cases managed in Spanish paediatric intensive care units (the MATUCIP Registry) was established with the aim of gaining knowledge on their clinical characteristics, diagnosis and acute-phase treatment.

METHODS

We conducted a prospective multicentre observational study in 20 paediatric intensive care units (PICUs) in Spain from January 2017 to December 2021 in children aged more than 1 month with TMAs, who were followed up through the discharge from the PICU.

RESULTS

The sample included 97 patients (51.5% female) with a median age of 2.6 years (interquartile range [IQR], 1.6-5.7). The initial manifestations were gastrointestinal (74.2%), respiratory (14.4%), fever (5.2%), neurologic (3.1%) and other (3.1%). At admission, 75.3% of patients had microangiopathic haemolytic anaemia, 95.9% thrombocytopenia and 94.8% acute kidney injury. Of the total sample, 57.7% of patients received a diagnosis of Shiga toxin-associated haemolytic uraemic syndrome (HUS), 14.4% of Streptococcus pneumoniae-associated HUS, 15.6% of atypical HUS, 10.3% of secondary TMA and 2.1% of thrombotic thrombocytopenic purpura. Eighty-seven patients (89.7%) developed arterial hypertension, and 49.5% gastrointestinal, 22.7% respiratory, 25.8% neurologic and 12.4% cardiac manifestations. Also, 60.8% required renal replacement therapy and 2.1% plasma exchange. Twenty patients received eculizumab. The median PICU stay was 8.5 days (IQR, 5-16.5). Two children died.

CONCLUSIONS

The MATUCIP registry demonstrates the clinical variability of TMA cases requiring admission to the PICU. Knowledge of the presentation and outcomes of TMAs can facilitate early aetiological diagnosis. This registry can help improve our understanding of the clinical spectrum of these diseases, for which there is a dearth of published data.