They included studies with hospitalized adult COVID-19 patients without major COVID-19-associated central nervous system (CNS) manifestations and with a measurement of blood NfL in the acute phase as well as data regarding at least one clinical outcome including intensive care unit (ICU) admission, need of mechanical ventilation (MV) and death. They also derived the age-adjusted measures NfL Z scores and conducted mixed-effects modelling to test associations between NfL Z scores and other variables, encompassing clinical outcomes. Summary receiver operating characteristic curves (SROCs) were used to calculate the area under the curve (AUC) for blood NfL.
382 records were identified, of which 7 studies were included with a total of 669 hospitalized COVID-19 cases (mean age 66.2 ± 15.0 years, 68.1% males). Median NfL Z score at admission was elevated compared to the age-corrected reference population (2.37, IQR: 1.13–3.06, referring to 99th percentile in healthy controls). NfL Z scores were significantly associated with disease duration and severity. Higher NfL Z scores were associated with a higher likelihood of ICU admission, need of MV, and death. SROCs revealed AUCs of 0.74, 0.80 and 0.71 for mortality, need of MV and ICU admission, respectively. The authors concluded underlying that blood NfL levels were elevated in the acute phase of COVID-19 patients without major CNS manifestations and associated with clinical severity and poor outcome. The marker might ameliorate the performance of prognostic multivariable algorithms in COVID-19.
Abdelhak A, Barba L, Romoli M, Benkert P, Conversi F, D'Anna L, Masvekar RR, Bielekova B, Prudencio M, Petrucelli L, Meschia JF, Erben Y, Furlan R, De Lorenzo R, Mandelli A, Sutter R, Hert L, Epple V, Marastoni D, Sellner J, Steinacker P, Aamodt AH, Heggelund L, Dyrhol-Riise AM, Virhammar J, Fällmar D, Rostami E, Kumlien E, Blennow K, Zetterberg H, Tumani H, Sacco S, Green AJ, Otto M, Kuhle J, Ornello R, Foschi M, Abu-Rumeileh S. Prognostic performance of blood neurofilament light chain protein in hospitalized COVID-19 patients without major central nervous system manifestations: an individual participant data meta-analysis. J Neurol. 2023 May 15.