Table 1.
Summary of individual studies and quality assessment scores
| Author | Year | Country | Condition(s) studied | ICHD criteria | Setting | Cytokines studied | NOS |
|---|---|---|---|---|---|---|---|
| Covelli et al. [19] | 1991 | Italy | M & T | 1 | NR | TNF-α | 4 |
| Shimomura et al. [20] | 1991 | Japan | M & T | I | OP | IL-2 | 7 |
| Martelletti et al. [21] | 1993a | Italy | C | I | OP | IL-1β | 8 |
| Martelletti et al. [22] | 1993b | Italy | M | I | IP | IL-4, IL-6 IFN-γ | 8 |
| Munno et al. [23] | 1998 | Italy | M | I | OP | IL-4, IL-8, IFN-γ | 8 |
| Martelletti et al. [24] | 2001 | Italy | M | I | NR | IL-2, IL-4, IFN-γ | 7 |
| Empl et al. [25] | 2003a | Germany | C | I | OP | IL-1β, IL-6 | 7 |
| Empl et al. [26] | 2003b | Germany | M | I | OP | IL-6, TNF-α | 7 |
| Sarchielli et al. [27] | 2004 | Italy | M | II | IP | IL-8 | 8 |
| Perini et al. [28] | 2005 | Italy | M | I | OP | IL-1β, IL-2, IL-4, IL-6, IL-10, TNF-α | 8 |
| Ishizaki et al. [29] | 2005 | Japan | M & T | I | OP | TGF-β | 8 |
| Sarchielli et al. [30] | 2006 | Italy | M | II | IP | IL-1β, IL-4, IL-6, TNF-α | 8 |
| Fidan et al. [31] | 2006 | Turkey | M | II | IP | IL-6, IL-10 | 7 |
| Koçer et al. [32] | 2009 | Turkey | M | II | OP | IL-6 | 6 |
| Bockowski et al. [33] | 2009 | Poland | M & T | II | IP | IL-1α, TNF-α | 8 |
| Koçer et al. [34] | 2010 | Turkey | T | II | OP | IL-8 | 8 |
| Bockowski et al. [35] | 2010 | Poland | M & T | II | IP | IL-4, IL-10, IL-13 | 5 |
| Uzar et al. [36] | 2011 | Turkey | M | II | IP | IL-1β, IL-2, IL-6, IL-10, TNF-α | 7 |
| Güzel et al. [37] | 2013 | Turkey | M | II | OP | TGF-β | 6 |
| Della Vidova et al. [38] | 2013 | Australia | T | II | OP | IL-2, IL-5, IL-10, IL-13, I IFN-γ, TGF-β, TNF-α | 8 |
| Wang et al. [39] | 2015 | China | M | II | OP | IL-6 | 8 |
| Lee et al. [40] | 2015 | Taiwan | M | III | OP | IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10 | 8 |
| Duarte et al. [41] | 2015 | Brazil | M | II | OP | IL-8 | 8 |
| Domingues et al. [42] | 2015 | Brazil | T | II | OP | IL-8 | 6 |
| Deitos et al. [43] | 2015 | Brazil | T | II | OP | IL-8, IL-12, TNF-α | 5 |
| Aydin et al. [44] | 2015 | Turkey | M | III | NR | IL-4, IL-5, IL-6, IL-10, IFN-γ, TNF-α | 7 |
| Yucel et al. [45] | 2016 | Turkey | M | II | IP | IL-1β, IL-6, TNF-α | 7 |
| Oliveira et al. [46] | 2017 | Brazil | M | II | OP | IL-6, IL-8, IL-10, TNF-α | 8 |
| Michalak et al. [47] | 2017 | Poland | M | II | OP | TNF-α | 8 |
| Martami et al. [48] | 2018 | Iran | M | III | OP | IL-6, TNF-α | 7 |
| Dominguez et al. [49] | 2018 | Spain | M | III | OP | IL-6, IL-10, TNF-α | 8 |
| Han et al. [50] | 2019 | China | M | III | OP | IL-1β, IL-2, IL-6, IL-10, TNF-α | 7 |
| Flook et al. [51] | 2019 | Spain | M | III | OP | IL-1α, IL-1β, IL-4, IL-6, IL-8, IFN-γ | 3 |
| Chaudhry et al. [52] | 2019 | Germany | M | III | NR | IL-1β, IL-6, IL-10, TNF-α | 8 |
| Togha et al. [53] | 2020 | Iran | M | III | OP | IL-6, TNF-α | 8 |
| Karaaslan et al. [54] | 2020 | Turkey | M | III | OP | IL-1β, IL-6, TNF-α | 7 |
| Dönder et al. [55] | 2021 | Turkey | M | III | OP | IL-18 | 8 |
| Cowan et al. [56] | 2021 | USA | M | III | OP | IL-6, IL-8, IL-10, IFN-γ, TNF-α | 6 |
IL-1α, IL-5, IL-12 and IL-13 were not used for meta-analysis as they were only reported in single studies for any of the comparisons of interest
Abbreviations: C Cluster headache, ICHD International Classification of Headache Disorders, IP Inpatient, M Migraine, NOS Newcastle–Ottawa score, NR Not recorded, OP Outpatient, T Tension-type headache