Inter alpha Inhibitor Proteins (IAIP) are naturally occurring plasma proteins that circulate in high concentrations in all mammals. IAIP have an important role in modulating host response to infection, trauma and inflammation. Bikunin deficient (and therefore IAIP deficient) mice are prone to infection and the females are severely infertile. There is no mammalian organism with known total deficiency of IAIP, supporting that functional IAIP is essential for mammalian species.

Primarily produced in the liver, IAIP are released into the blood and a subunit (bikunin) is excreted in the urine. IAIP have significant protective effects during inflammatory events and importantly the protective effects of IAIP are independent from the causative microbial agents or triggers.


Based on ProThera Biologic’s studies, IAIP are expected to be beneficial in a broad range of acute inflammatory states such as lung and neuro inflammation. IAIP may be used as an adjunctive therapy in reducing morbidity and mortality associated with the dysregulated host response in combination with more specific therapies targeting the elimination of the causative agents/triggers.

IAIP levels have been shown to be high in healthy individuals yet drop markedly, 50-90%, during acute inflammation. In studies of over 2000 human blood samples; ProThera has shown IAIP levels to be inversely correlated with disease severity and mortality. Blood levels of IAIP decrease when the proteins enter into the tissues and interact with Extra Cellular Matrix proteins to aid in epithelial recovery after injury. The same drop in IAIP levels has been demonstrated in numerous animal models and replacement therapy with IAIP has been shown to reverse and prevent disease progression. The data support the concept that if a patient’s IAIP levels are low, that patient is in need of urgent care and that replacement therapy with IAIP may significantly reduce the inflammatory burden and improve patient outcomes.

ProThera Biologics also has developed an immunoassay to quantitatively detect levels of IAIP in patients. This “severity marker” test is currently available as a lab-based ELISA and as a lateral flow rapid test in the prototype stage. An IAIP biomarker test will be used in conjunction with clinical trial development and the Company plans to further develop the rapid test as a commercial product.