mGem: When immunity turns against itself-GM-CSF autoantibodies drive opportunistic infection risk.

Anti-cytokine autoantibodies represent an expanding field in immunology, and their study has revealed crucial insights into immune cell dysfunction. These autoantibodies are now classified by the International Union of Immunological Societies (IUIS) as phenocopies of primary immunological deficiencies within the broader category of inborn immunity defects. Indeed, the critical importance of these autoantibodies became starkly apparent during the COVID-19 pandemic when patients with type I interferon autoantibodies showed significantly higher rates of severe illness. This review examines how neutralizing autoantibodies, exemplified by those targeting granulocyte monocyte stimulating factor, can compromise immune function in otherwise immunocompetent individuals, making them more susceptible to specific fungal and bacterial infections. This understanding highlights the crucial role of anti-cytokine antibodies in infection susceptibility and immune system regulation.