title: Rare association of insulin autoimmune syndrome with ankylosing spondylitis.
abstract: Insulin autoimmune syndrome (IAS) is a rare cause of hyperinsulinemic hypoglycaemia, which is known to occur in association with the use of sulfhydryl-containing drugs and autoimmune disorders. We describe a patient with hitherto an unreported association of IAS with ankylosing spondylitis. We have also performed and described a simplified method of polyethylene glycol (PEG) precipitation of an insulin bound antibody in the serum.
  
  
  CONCLUSIONS
  IAS should be considered in differential diagnosis of endogenous hyperinsulinemic hypoglycaemia.Ankylosing spondylitis can be associated with IAS apart from several other autoimmune diseases.Very high serum insulin levels (100-10 000 μU/ml) are frequently seen in IAS.When faced with very high serum insulin before suspecting insulinoma, it is advisable that PEG precipitation of serum be done to identify antibody bound insulin.A clinical suspicion of IAS can avoid expensive imaging and unnecessary surgery in affected patients.
authors.affiliation: Department of Endocrinology and Metabolism , All India Institute of Medical Sciences , New Delhi , India.
authors.forename: Nishant
authors.initials: N
authors.lastname: Raizada
authors.affiliation: Department of Endocrinology and Metabolism , All India Institute of Medical Sciences , New Delhi , India.
authors.forename: S H
authors.initials: SH
authors.lastname: Rahaman
authors.affiliation: Department of Radiology , All India Institute of Medical Sciences , New Delhi , India.
authors.forename: D
authors.initials: D
authors.lastname: Kandasamy
authors.affiliation: Department of Endocrinology and Metabolism , All India Institute of Medical Sciences , New Delhi , India.
authors.forename: V P
authors.initials: VP
authors.lastname: Jyotsna