Case Report: Atypical HUS Presenting With Acute Rhabdomyolysis Highlights the Need for Individualized Eculizumab Dosing

Updates in atypical hemolytic syndrome

PURPOSE OF REVIEW

This review aims to summarize how scientific advances in complement biology have not only improved the diagnosis and management of aHUS but also continue to offer insights into the pathophysiology of complement-mediated disease that may be leveraged for future therapeutic developments.

RECENT FINDINGS

Updated information on the clinical and epidemiological features, pathophysiology, diagnosis, management, and potential for future therapeutic advancements in the treatment of aHUS are reviewed.

SUMMARY

aHUS is a rare but potentially life-threatening disease that requires prompt diagnosis and treatment as well as long-term management via a multidisciplinary team providing coordination of primary and specialty care as well as outreach and education for children and families affected by this life-long disease.

Granulocyte activation markers in cerebrospinal fluid differentiate acute neuromyelitis spectrum disorder from multiple sclerosis

BACKGROUND

Granulocyte invasion into the brain is a pathoanatomical feature differentiating neuromyelitis optica spectrum disorder (NMOSD) from multiple sclerosis (MS). We aimed to determine whether granulocyte activation markers (GAM) in cerebrospinal fluid (CSF) can be used as a biomarker to distinguish NMOSD from MS, and whether levels associate with neurological impairment.

METHODS

We quantified CSF levels of five GAM (neutrophil elastase, myeloperoxidase, neutrophil gelatinase-associated lipocalin, matrixmetalloproteinase-8, tissue inhibitor of metalloproteinase-1), as well as a set of inflammatory and tissue-destruction markers, known to be upregulated in NMOSD and MS (neurofilament light chain, glial fibrillary acidic protein, S100B, matrix metalloproteinase-9, intercellular adhesion molecule-1, vascular cellular adhesion molecule-1), in two cohorts of patients with mixed NMOSD and relapsing-remitting multiple sclerosis (RRMS).

RESULTS

In acute NMOSD, GAM and adhesion molecules, but not the other markers, were higher than in RRMS and correlated with actual clinical disability scores. Peak GAM levels occurred at the onset of NMOSD attacks, while they were stably low in MS, allowing to differentiate the two diseases for ≤21 days from onset of clinical exacerbation. Composites of GAM provided area under the curve values of 0.90-0.98 (specificity of 0.76-1.0, sensitivity of 0.87-1.0) to differentiate NMOSD from MS, including all anti-aquaporin-4 protein (aAQP4)-antibody-negative patients who were untreated.

CONCLUSIONS

GAM composites represent a novel biomarker to reliably differentiate NMOSD from MS, including in aAQP4- NMOSD. The association of GAM with the degree of concurrent neurological impairment provides evidence for their pathogenic role, in turn suggesting them as potential drug targets in acute NMOSD.