Elevated NLR and D-Dimer May Distinguish MIS-A From Acute COVID-19

Adults with multisystem inflammatory syndrome (MIS-A) tend to exhibit specific symptoms and laboratory findings earlier during their hospitalization compared with patients experiencing acute symptomatic COVID-19. These characteristics can aid in diagnosing and treating MIS-A, according to study results published in Clinical Infectious Diseases.

Investigators conducted a retrospective cohort study including adult patients who were hospitalized with MIS-A at 6 US academic medical centers between March 1, 2020 and December 31, 2021.

Patients with MIS-A were matched with patients hospitalized with acute symptomatic COVID-19 in a 1:2 ratio based on age group, sex, site, and admission date.

The investigators compared the characteristics, symptoms, test results, treatments, and outcomes of patients hospitalized with MIS-A vs acute symptomatic COVID-19.

Study endpoints included: demographics, laboratory/imaging results, comparison of presenting symptoms (with a focus on gastrointestinal symptoms), and clinical outcomes (hospitalization duration, intensive care unit admission, invasive mechanical ventilation requirement, use of vasopressors, and mortality rate).

A total of 53 patients with MIS-A were matched with 106 patients with acute symptomatic COVID-19. The analysis indicated that patients with MIS-A were more likely to be non-Hispanic Black (46% vs 21%) and less likely to be non-Hispanic White (6.0% vs 26%) compared against patients with COVID-19, respectively.

Patients with MIS-A vs COVID-19 were less likely to have underlying medical conditions or exhibit symptoms such as cough (36% vs 86%) and difficulty breathing (62% vs 87%).

Those with MIS-A were more likely to have had a laboratory-confirmed case of COVID-19 at least 14 days before being admitted to the hospital (26% vs 3.0%) vs patients hospitalized with COVID-19, respectively. Additionally, compared against patients hospitalized with COVID-19, patients with MIS-A were more likely to receive SARS-CoV-2 serology testing (43% vs 17%) and test positive (96% vs 61%).

Patients with MIS-A were more likely to experience abdominal (30% vs 4.0%) and chest pain (36% vs 20%) upon presentation, vs those hospitalized with COVID-19, respectively.

Upon admission, compared against patients with COVID-19, patients with MIS-A showed higher levels of neutrophil-to-lymphocyte ratio (NLR), C-reactive protein, ferritin, procalcitonin, and D-dimer.

Over 75% of all patients with MIS-A and COVID-19 received respiratory support. However, patients with MIS-A had longer hospital stays (median length, 9 vs 5 days) and were more likely to require intensive care (72% vs 20%), invasive mechanical ventilation (32% vs 11%), and vasopressors (58% vs 10%). The mortality rate was the same for both cohorts, at 6%. 

This study was limited by inconsistencies in completion of certain diagnostic tests, which may have limited detection of MIS-A. Additionally, some symptoms of MIS-A (certain skin and mucous membrane findings) may not have been reported in electronic medical records, making it more difficult to identify.

The study authors concluded, “This multicenter retrospective cohort study indicates MIS-A is a rare complication of SARS-CoV-2 infection and has a more severe presentation and hospital course than COVID-19.”

Disclosure: One or more of the study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.