Reduced expression of interleukin 8 and interferon-gamma cytokines identified in long COVID medrxivpreprint UofUMedicine COVID19 SARSCoV2 LongCOVID
By Pooja Toshniwal PahariaOct 10 2022Reviewed by Aimee Molineux In a recent study posted to the medRxiv* preprint server, researchers compared serum cytokine expression among healthy individuals and those with PASC [post-acute sequelae of coronavirus disease 2019 ].
Serum samples were obtained from 12 PASC patients, and 15 healthy individuals between May 2020 and December 2021, and their peripheral blood mononuclear cells were isolated for performing multiplexed cytokine assays. The assays included interleukin -1β, 2, 4, 5, 6, 8, 10, 12, 13, 17, 33, interferon-gamma , tumor necrosis alpha and soluble IL-2 receptor .
Results and discussion PASC patients showed a 100% reduction in IL-8 and IFNγ expression with significant reductions in the expression of IL-2, 4, 6, 13, and 17. Therefore, the team proposed immune exhaustion as the driving factor of PASC, with a complete IL-8 and IFNγ reduction preventing the pulmonary tissues and other tissues from recovering post-acute COVID-19, which decreased the capability to prevent subsequent COVID-19, both contributing to the PASC symptomatology.
Of note, the observed reduction in IL-5 expression among PASC women showed statistical significance when only females of both cohorts were considered, which dropped to 14% with no significance when both the groups were compared, including both genders. On the contrary, the alterations in TNFα, sIL-2R, IL-1β, 10, and 12 expressions remained non-significant irrespective of the genders considered.