**Background of PGM3 Antibodies**
Phosphoglucomutase 3 (PGM3) is an enzyme critical in the glycosylation pathway, catalyzing the conversion of N-acetylglucosamine (GlcNAc)-6-phosphate to GlcNAc-1-phosphate. This step is essential for synthesizing UDP-GlcNAc, a key substrate for N-linked and O-linked glycoprotein modifications. PGM3 deficiency, caused by autosomal recessive hypomorphic mutations, disrupts glycosylation and is linked to a congenital disorder of glycosylation (PGM3-CDG). This condition manifests as severe immune dysregulation, including recurrent infections, autoimmune phenomena, and atopic disorders.
PGM3 autoantibodies have recently emerged as biomarkers in autoimmune and inflammatory diseases. Studies report elevated PGM3 antibody levels in subsets of patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and other autoimmune conditions. These autoantibodies may arise from aberrant immune responses to improperly glycosylated proteins, a hallmark of PGM3 dysfunction. Additionally, PGM3 antibodies are explored in cancer research, as altered glycosylation is common in malignancies.
Research on PGM3 antibodies aims to clarify their pathogenic role—whether they contribute to disease progression or are secondary to underlying glycosylation defects. Their clinical utility as diagnostic or prognostic tools remains under investigation. Understanding PGM3-related pathways and autoimmunity may unveil novel therapeutic targets for immune-mediated diseases.