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The following is a summary of “PLASMIC score to aid diagnosis of aHUS: an analysis of C5 inhibitor clinical trials and the PINC AI™ healthcare database,” published in the May 2025 issue of BMC Nephrology by Uriol-Rivera et al. 

Atypical hemolytic uremic syndrome (aHUS) was recognized as a thrombotic microangiopathy (TMA), microangiopathic hemolytic anemia causing end organ damage and death without treatment, highlighting the importance of quickly distinguishing it from other TMA forms for optimal management.  

Researchers conducted a retrospective study to evaluate the distribution of PLASMIC Scores in patients with aHUS and assess its diagnostic utility in confirmed TMA cases.  

They used data from the eculizumab (NCT01194973) and ravulizumab (NCT02949128) clinical trials to calculate and assess PLASMIC Score distribution in individuals with aHUS. Real-world patient-level data from the PINC AI^TM Healthcare Database (PHD) were analyzed to evaluate PLASMIC Score performance in detecting aHUS among 110 individuals with documented TMA and renal impairment (primary analysis population). Sensitivity analyses were also conducted in alternative populations.  

The results showed that 94 individuals with aHUS were analyzed from the eculizumab and ravulizumab clinical trials. In the eculizumab trial, 18 out of 36 (50.0%) had a PLASMIC Score of 4, while 27 out of 58 (46.6%) in the ravulizumab trial had the same score. Around 85% had scores ≤ 5 (range: 3–5), with similar distribution across trials. In the PHD cohort of 110 individuals with undifferentiated TMA, a PLASMIC Score cutoff of ≤ 5 resulted in a sensitivity of 86.5%, specificity of 71.4%, positive predictive value of 92.8%, and negative predictive value of 55.6% for detecting probable aHUS. Further analyses confirmed similar results at the same cutoff. A cutoff of ≤ 4 lowered the positive predictive value to 62.9% but increased the negative predictive value to 85.7%, with only 3 cases misclassified as thrombotic thrombocytopenic purpura (TTP).  

Investigators concluded that applying the PLASMIC Score in the aHUS diagnostic pathway supported clinical decision-making and improved confidence in earlier identification and timely treatment, potentially enhancing outcomes. 

Source: bmcnephrol.biomedcentral.com/articles/10.1186/s12882-025-04156-6