CS and systemic lupus erythematosus: For IgM nAAbs, they found that natural IgM autoantibodies to citrate synthase (CS) are present from infancy, remain stable in adults, may serve as a first line of defense against pathogens, and exhibit unique epitope recognition patterns in pathological conditions such as systemic lupus erythematosus (SLE), suggesting a potential link between innate immunity and autoimmune processes [97,120].