Polyuria associated with an antibody to vasopressin

Area of Science:

• Endocrinology
• Immunology
• Nephrology

Background:

• Diabetes insipidus is a condition characterized by polyuria, often treated with vasopressin (antidiuretic hormone).
• Therapeutic resistance can occur, necessitating investigation into underlying mechanisms.

Observation:

• A patient diagnosed with diabetes insipidus developed resistance to vasopressin (Pitressin) therapy after 18 months.
• Circulating antibodies to vasopressin were detected in the patient's serum.

Findings:

• Antibody titers decreased, and maximal urinary concentration improved upon withdrawal of vasopressin therapy.
• The identified vasopressin antibody was associated with the IgA immunoglobulin fraction.

Implications:

• This case demonstrates immune-mediated resistance to exogenous vasopressin in diabetes insipidus.
• Understanding antibody characteristics is crucial for managing therapeutic resistance in endocrine disorders.