The utility of serum amyloid a and other acute-phase reactants determination in ambulatory care COVID-19 patients

Abstract

Background: The unpredictable course of Coronavirus Disease 19 (COVID-19) is making good severity assessment tools crucial. This study aimed to assess the usefulness of serum amyloid A (SAA) and other acute-phase reactants (APRs) in ambulatory care COVID-19 patients and identified relationships between these markers and disease outcomes. Methods: From August to November 2020, patients seen in the outpatient department of the Clinic for Infectious and Tropical Diseases (Belgrade, Serbia) with confirmed COVID-19 were included. Patients were classified into mild, moderate, and severe disease groups based on World Health Organization criteria. SAA, C-reactive protein (CRP), interleukin-6 (IL-6), procalcitonin (PCT), ferritin, fibrinogen, D-dimer, albumin, and transferrin were measured. The median values of all APRs were compared between COVID-19 severity groups, hospitalized and non-hospitalized patients, and survivors and non-survivors. The Receiver operator characteristic (ROC) curve analysis was used for the classification characteristics assessment of individual APRs for the severity of illness, hospitalization, and survival. Results: Higher levels of SAA, CRP, IL-6, PCT, and lower levels of transferrin and albumin were observed in severe cases, hospitalized patients, and non-survivors. Based on ROC curve analysis AUC for SAA has fair classification performance for disease severity (0.794) and death (0.732) and good performance for hospitalization (0.853). Conclusion: SAA is a valuable marker in everyday practice for assessing COVID-19 severity and prognosis in ambulatory patients.

Uvod: Tok koronavirusne bolesti 2019 (COVID-19) je nepredvidiv, zbog čega su neophodni dobri alati za procenu težine ove infekcije. Svrha ovog istraživanja je procena značaja određivanja serumskog amiloida A (SAA) i drugih reaktanata akutne faze (RAF) kod ambulantnih pacijenata sa COVID-19, kao i identifikacija veze između ovih markera i ishoda bolesti. Metode: Od avgusta do novembra 2020. godine, u studju su uključeni pacijenti koji su pregledani u Prijemnoj ambulanti Klinike za infektivne i tropske bolesti (Beograd, Srbija), sa potvrđenim COVID-19. Pacijenti su bili klasifikovani u grupe blage, umerene i teške bolesti na osnovu kriterijuma Svetske zdravstvene organizacije. Određivane su vrednosti SAA, C-reaktivnog proteina (CRP), interleukina-6 (IL-6), prokalcitonina (PCT), feritina, fibrinogena, D-dimera, albumina i transferina. Medijane vrednosti RAF su poređene između grupa težine bolesti, bolesnika koji su bili hospitalizovani i onih koji nisu, kao i preživelih i preminulih. Korišćena je analiza Receiver operator characteristic (ROC) krive i Area-under-curve (AUC) za analizu klasifikacionih karakteristika pojedinačnih RAF za težinu bolesti, hospitalizaciju i preživljavanje. Rezultati: Viši nivoi SAA, CRP, IL-6, PCT i niži nivoi transferrina i albumina su uočeni kod osoba sa teškim oblikom bolesti, hospitalizovanih pacijenata i preminulih. Na osnovu analize ROC krive, AUC za SAA je pokazao zadovoljavajuće klasifikacione performanse za težinu bolesti (0,794) i smrtni ishod (0,732) i dobre performanse za hospitalizaciju (0,853). Zaključak: SAA je vredan marker u svakodnevnoj praksi za procenu težine i prognoze COVID-19 kod ambulantnih pacijenata.