Abstract: The present invention provides methods for diagnosing and treating an immune-mediated disease, e.g., an autoimmune disease, an allergy or an inflammatory disease. Diagnosis is made by detecting a heterozygous or homozygous genotype of haptoglobin 2 or by detecting and quantifying pre-haptoglobin 2 mRNA or protein. After diagnosis, the disease may be treated by decreasing cell permeability leading to increased transepithelial electrical resistance, for example, by administering an antibody directed against single chain zonulin thereby inhibiting epidermal growth factor receptor and inhibiting proteinase-activated receptor 2 (PAR2).

Abstract: Provided herein are a methods of reducing a level of activity of a sialyl transferase enzyme, a sialidase enzyme or a combination thereof using inhibitors of these enzymes, for example specific inhibitory compound or antibodies directed against the enzymes. The methods are effective to treat an inflammatory disease or disorder or a primary or metastatic cancer. Also provided is a method for screening potential inhibitors of sialyl transferase enzymes.