Table 1. Characteristics of included studies measuring peripheral circulating cytokine concentration.
| Study/Year | Cytokines Measured | Country | Samples (DS/Control) | Gender (% Male) (DS/Control) | Mean Age (DS/Control) | Sample Source | Assay type |
|---|---|---|---|---|---|---|---|
| Barr-Agholme et al. 1997 | IL-1β | Sweden | 15/15 | NA | 12.1/13.8 | GCF | ELISA |
| Broers et al. 2012 | IFN-γ, IL-1β, IL-6, IL-8, IL-10, TNF-α | Netherlands | 61/57 | 64/40 | 7.8/9.3 | Blood | Cytometric Bead Assay, ELISA |
| Carta et al. 2002 | IFN-γ, IL-6, TNF-α | Italy | 19/19 | 68.4/68.4 | 30.11/30.27 | Blood | ELISA |
| Cattell et al. 1989 | Neopterin | UK | 53/32 | NA | NA | Urine | HPLC |
| Cetiner et al. 2010 | IL-1β, IL-4, IL-6, IL-8, IL-10, TNF-α | Turkey | 32/32 | 43.8/56.2 | 3.9/4.5 | Blood | ELISA |
| Coppus et al. 2010 | Neopterin | Netherlands | 401/48 | 62.3/66.7 | 52/50.2 | Blood | HPLC |
| Dogliotti et al. 2010 | IL-6 | Italy | 50/30 | NA | NA | Blood | biochip array analyzer |
| Licastro et al. 2005 | IL-6, Neopterin | Italy | 40/20 | NA | NA | Blood | ELISA |
| Mehta et al. 2007 | Neopterin | USA | 35/34 | 80.0/58.8 | 7.17/10.71 | Blood | ELISA |
| Mehta et al. 2005 | Neopterin | USA | 38/37 | 50/51.4 | 45/44 | Blood | ELISA |
| Nelson et al. 2006 | IL-8 | USA | 46/40 | NA | NA | Blood | xMAP Luminex |
| Parisotto et al. 2015 | IL-1β, TNF-α | Brazil | 21/18 | 55.6/57.1 | 7.7/6.7 | Blood | ELISA |
| Rodrigues et al. 2014 | IFN-γ, IL-1β, IL-6, IL-10, TNF-α | Brazil | 23/23 | 47.8/39.1 | 28.3/27.7 | Blood | ELISA |
| Rostami et al. 2012 | IFN-γ , IL-10, TNF-α | Iran | 24/24 | 45.8/NA | 5.75/5.75 | Blood | ELISA |
| Shimada et al. 2007 | IFN-γ, IL-1β, IL-4, IL-6, IL-8, IL-10, TNF-α | Japan | 15/10 | NA | NA | Blood | Multiplex Suspension Array System |
| Smigielska-Kuzia et al. 2010 | IL-4, IL-10 | Poland | 5/10 | NA | NA | Blood | ELISA |
| Torre et al. 1995 | IFN-γ | Italy | 12/20 | NA | 38.3/34.9 | Blood | ELISA |
| Tsilingaridis et al. 2012 | IFN-γ, IL-1β, IL-4, IL-6, IL-10, TNF-α | Sweden | 24/29 | 54.2/48.3 | 16.4/16.4 | GCF | Bio-Plex Cytokine Assay |
| Zaki et al. 2017 | IL-6, TNF-α | Egypt | 43/43 | 46.5/51.2 | 6.4/6.3 | Blood | ELISA |
Abbreviations: DS, Down syndrome; IL, interleukin; GCF, gingival crevicular fluid; ELISA, enzyme linked immunosorbent assay; IFN-γ, interferon-γ; TNF-α, tumor necrosis factor-α; HPLC, high performance liquid chromatography; NA, not available.