Table 2 Blood-based prognostic biomarkers of inflammation in ALS
From: Blood-based biomarkers of inflammation in amyotrophic lateral sclerosis
Measured biomarker | Method of detection | Mean disease duration at sample donation | Number of samples | Potential Prognostic Value | Study Reference Clinical Trial ID |
|---|---|---|---|---|---|
Blood-derived markers | |||||
 IL-2, IL-6, IL-10, IFN-γ, and TNF | Plasma, BioPlex | 21.37 months (median) | n = 79 ALS | IL-6 correlated with ALS-FRS-R and Manual Muscle Testing. | Tortelli et al., 2020 [29] |
 CD14, LBP and CRP | Serum; ELISAs | Not reported | n = 68 ALS (1st cohort) n = 100 ALS (2nd cohort) | - soluble CD14 correlated to burden of disease and progression rate (both cohorts) - LBP correlated to burden of disease and progression rate (2nd cohort) - CRP correlated to burden of disease and progression rate (2nd cohort) | Beers et al., 2020 [26] |
 IL-1b, IL-6, IL-10, IL-12, TNF, IFNg, IL17a, and IL-23 | Serum; ELISAs | 2.48 years | n = 73 ALS | - IL-1b was increased in fast progressive ALS - IL-6 correlated with disease duration (weak correlation) - IL-1b correlated with the ALSFRS-R slope | Jin et al., 2020 [27] |
 CD5L, Ficolin-3 | Plasma; ELISAs | 739.9 months (median) | n = 37 ALS | - CD5L was correlated with disease duration and survival (not with ALS-FRS). - Ficolin-3 was not correlated to disease parameters. | Mohanty et al., 2020 [30] |
 CRP | Serum; standard laboratory tests | Retrospective study of newly diagnosed ALS patients with up to 5 years of follow-up (average 2.36 years). | n = 399 ALS(n = 122 very fast progressors, n = 88, medium progression, n = 189 slow progression) | - Patients with a higher CRP (log-transformed) at baseline had a higher risk of mortality. - Patients with a higher CRP (log-transformed) than at baseline had a higher risk of mortality. - CRP (log-transformed) increases in the last few months prior to death in the medium and fast progressing patients) | Sun et al. 2020 [67] |
 CRP | Serum; standard laboratory tests |  | n = 384 ALS n = 116 ALS (replication study) | Increased serum CRP is correlated with an increased rate of functional decline. | Lunetta et al., 2017 [69] (NCT01281631) |
 wide-range C-reactive protein (wrCRP) concentrations | From whole blood | Not reported | n = 80 ALS (n = 41 ALS at follow-up 3-6 m after initial donation; n = 22 ALS patients at the third donation, and at least 3 months after the second) | - Correlation between the ALSFRS-R and the wrCRP concentration at the first examination. | Keizman et al., 2008 [28] |
 IL-6 | Plasma; Human Magnetic Luminex Screening Assay | Collection at 1, 6, 12, and 18 months into the clinical trial | n = 109 ALS participants measured over 4 time points | No correlation with ALS-FRS-R | Devos et al., 2019 [70] NCT:00868166 |
 IL-6 | Plasma; Bio-Plex Pro Human Chemokine assay. | 25.7 months | n = 82 ALS | Reduction in phrenic nerve CMAP amplitude and FVC was correlated with increased IL-6 levels | Pronto-Laborinho et al., 2019 [33] |
 IP-10, MCP-1, MIG, RANTES,  IL-2, IL-4, IL-6, IL-8, IL-10, IL-17a, TNF, IGF-g, sTNFR1, sTNFR2 | Plasma; cytometric bead array and ELISA | 3 years | n = 68 ALS n = 24 ALS at the second time point (6–12 months later) | No correlation with ALS-FRS-R for any tested markers. | Prado et al., 2018 [34] |
 CC-16 | Plasma; ELISA | 27 months | n = 81 ALS | No correlation with age, onset region, disease duration, functional status, FVC, and PhrenAmpl. | Pronto-Laborinho et al., 2017 [37] |
 IL-1β, IL-18, IL-33, IL-37, IL-1Ra, sIL-1R2, IL-18BP, sIL-1R4 | Serum; individual ELISAs | 11.32 months | n = 144 sporadic ALS | No correlations with the ALS-FRS-R were detected. | Italiani et al., 2014 [40] |
 TGF-b, IL-6, TNF, IL-17A | Serum; individual ELISAs | From 3 to 96 months | n = 21 ALS | No correlation between the 4 cytokines and months after diagnosis. | Liu et al., 2012 [71] |
 TNF, IFN-γ, and NO | Serum; individual ELISAs and NO by determining nitrite and nitrate levels | 12 months | n = 22 ALS | Correlation between TNF-a, IFN-γ, and NO levels and disease duration | Babu et al., 2008 [45] |
 RANTES | Serum; individual ELISA | Not reported | n = 20 ALS | No correlation with serum RANTES and disease duration. | Rentzos et al., 2008 [46] |
 TGF-b, IL-6, TNF, IL-17A | Serum; individual ELISAs | From 3 to 96 months (range) | n = 21 ALS | TGF-β and IL-6 were increased in some patients since the onset of symptoms, whereas IL-17A and TNF-α levels were increased only in the mid-course of the disease (no statistics reported) | Liu et al., 2012 [71] |
Blood-derived cells, in vitro assays | |||||
 Monocyte subpopulations | Monocyte isolation kit from peripheral blood, and flow cytometry | Not reported | n = 68 ALS (1st cohort) n = 100 ALS (2nd cohort) | - CD14−/low/CD16+ monocytes negatively correlated with disease burden and rate of progression in ALS | Beers et al., 2020 [26] |
 Subpopulations of T cells, B cells, natural killer cells, and antigen presenting cells | Peripheral blood and FACS | 2.48 years | n = 73 ALS | - increased NK cells in slow vs fast progressive ALS - no difference between slow and fast progressive ALS for any other cell population - Th1/Th2 ratio correlated with the ALSFRS-R slope - Th17/Treg ratio correlated with the ALSFRS-R | Jin et al., 2020 [27] |
 Concentrations of TNF, IL-1β, IL-6, IL-12p40, IL-8, CCL2 and IL-10 in DC supernatants | Circulating myeloid dendritic (CD1chigh) cells stimulated with LPS. | Not calculated | n = 52 ALS | Inverse correlation between the time from onset to diagnosis and the levels of IL-6 secretion induced by LPS. | Rusconi et al., 2017 [54] |
 116 leukocyte populations and phenotypes from lymphocytes, monocytes, and granulocytes | Peripheral blood immunophenotyping by flow cytometry | 21.6 months | n = 80 ALS | Different immuno-phenotypic markers associate with clinical parameters, incl. Survival, in the 2 ALS immune profiles. | Gustafson et al., 2017 [55] |
 Transcriptomic analysis | RNA sequencing of blood monocytes | Not reported | n = 43 ALS | ALS monocytes from rapidly progressing patients had more proinflammatory DEGs than monocytes from slowly progressing patients. | Zhao et al., 2017 [56] |
 Transcriptomic and methylation analysis | RNAseq and RRBS on PBMCs | Not reported | 1 discordant twin pair | - Higher abundance of CD14 macrophages in ALS over time - Lower abundance of T cells in ALS over time | Lam et al., 201 6[57] |
 CD16 and HLA-DR | Surface expression, measured by flow cytometry from monocytes isolated from whole blood | 24.1 months | n = 24 ALS | - CD14 correlated with ALS-FRS-R rate of change - CD14/HLA-DR correlated with ALS-FRS-R rate of change | Miller et al., 2014 [72] NCT01091142, Ph1 NP001 in ALS |
 monocyte and lymphocyte populations and activation | Surface expression, measured by flow cytometry from monocytes isolated from whole blood | 4–93 months (range) | n = 38 sALS | - HLA-DR expression on CD14+ cells correlated with ALSFRS-R | Zhang et al., 2005 [61] |
 Leukocyte number and expression of FoxP3, TGF-b, IL-4, Gata-3, IL-10, Tbx21, IFN-γ | T-lymphocytes assessed by flow cytometry, and gene expression by RT-qPCR | Not reported | n = 54 ALS n = 102 ALS (replication) | - Number of Tregs and their FoxP3 protein expressions were reduced in rapidly progressing ALS patients and inversely correlated with progression rates (AALS). - The mRNA levels of FoxP3, TGF-b, IL4 and Gata3, were reduced in rapidly progressing patients and inversely correlated with progression rates. - FoxP3 and Gata3 were indicators of progression rates. - No differences in IL10, Tbx21, or IFN-γ expression were found between slow and rapidly progressing patients. | Henkel et al., 2012 [73] |