Pediatric atypical hemolytic-uremic syndrome due to auto-antibodies against factor H: is there an interest to combine eculizumab and mycophenolate mofetil?

BACKGROUND

Atypical hemolytic and uremic syndrome (aHUS), a thrombotic micro-angiopathy (TMA) caused by deregulation in the complement pathway, is sometimes due to the presence of anti-complement factor H (CFH) auto-antibodies. The "standard" treatment for such aHUS combines plasma exchange therapy and immunosuppressive drugs. Eculizumab, a monoclonal antibody that blocks the terminal pathway of the complement cascade, could be an interesting alternative in association with an immunosuppressive treatment for maintenance regimen.

CASE-DIAGNOSIS/TREATMENT

We report on two children, diagnosed with mildly severe aHUS due to anti-CFH antibodies, who were treated with the association eculizumab-mycophenolate mofetil (MMF). Neither side effects nor relapses were observed during the 3 years of follow-up; MMF was even progressively tapered and withdrawn successfully in one patient.

CONCLUSIONS

The association of eculizumab and MMF appears to be an effective and safe option in pediatric cases of aHUS due to anti-CFH antibodies of mild severity.

Combined use of creatinine and cystatin C improves the detection of renal dysfunction in children undergoing home parenteral nutrition

BACKGROUND

Renal dysfunction can complicate home parenteral nutrition (HPN). The aims were, in the context of pediatric HPN, to assess renal function using the measured glomerular filtration rate (mGFR), determine the most accurate formula(s) to estimate GFR, and identify possible underlying mechanisms of renal impairment.

METHODS

A retrospective study was performed in 2 centers. Patients receiving HPN and aged 2-16 years without medical history of nephropathy were included. GFR was measured using iohexol clearance. Estimated GFR (eGFR) was calculated using creatinine, cystatin C-based, and combined (eGFR_cr+cyst ) Schwartz formulas.

RESULTS

A total of 36 patients (18 females) were included; they received HPN for 8 (2-16) years. The primary digestive disease was short-bowel syndrome for 16 (44%) patients, gastrointestinal motility disorder for 10 (28%), or congenital diarrhea for 10 (28%). The median (range) mGFR was 99 (33-136) ml/min/1.73 m² ; 9 (25%) patients had mildly decreased mGFR (<90 and ≥60 ml/min/1.73 m² ), and 2 (6%) had mildly to severely decreased mGFR (<60 ml/min/1.73 m² ). The eGFR_cr+cyst formula was the most accurate and precise to estimate GFR. A significant negative correlation between mGFR and PN duration was found for patients receiving PN for 6-7/7 days (P = .008). Activation of the renin-angiotensin system was identified in 15 of 36 (42%) patients.

CONCLUSION

Renal dysfunction was frequent and correlated with the duration of PN only for patients with the most severe intestinal failure. The use of eGFR_cr+cyst improves its detection in these patients. Chronic dehydration may be an underlying mechanism.

Increasing use of linezolid in a tertiary NICU during a 10-year period: reasons and concerns for the future

Background

Linezolid has been increasingly used in tertiary NICUs. The objectives of this study were to explore the indications of these linezolid prescriptions, to analyze a possible misuse and to provide solutions to avoid such misuse.

Methods

A monocentric retrospective cohort study included all neonates hospitalized in one tertiary NICU between January 1st, 2010 and December 31st, 2019 and who received at least one administration of linezolid. These data were confronted to epidemiological and antibiotic use data from the same NICU. Two independent pediatricians secondarily classified linezolid uses as adequate or not.

Results

During the study period, 66 infections in 57 patients led to linezolid use. Most patients were pre-term and 21 patients (37%) died. Infections were mainly related to methicillin-resistant coagulase negative staphylococci and were frequently either pneumoniae (35%) or isolated bacteremia (48%), including 25 persistent bacteremia (64% of the 39 bacteremia). Need for a better tissue distribution or first-line treatment failure were the main reasons to initiate linezolid. Linezolid was administered for a median duration of 7 [3;10] days. No side effects were reported. Twenty-two (33%) of the 66 linezolid prescriptions were retrospectively classified as inadequate.

Conclusions

A rapid increase in linezolid prescriptions has been observed in our tertiary NICU, from 2014 to 2019, with 33% inadequate uses. This worrisome trend should lead to search for therapeutic alternatives and to work on antibiotic stewardship to prevent the emergence of new antimicrobial bacterial resistance.