Proteinuria and proximal tubule lesions induced by an anti-integrin monoclonal antibody treatment: case report.

Blocking integrin binding to fibronectin by a monoclonal antibody directed to integrin receptors induces apoptosis of proliferating endothelial cells. We report a case of grade 2 proteinuria, occurred fifteen days after the first administration of an anti-integrin monoclonal antibody associated to standard doses of carboplatin/paclitaxel and to a single dose of zoledronic acid in a patient treated in first line setting for a metastatic non small cell lung cancer. Kidney biopsy revealed a tubular damage probably associated to minimal change glomerulonephritis. Even if this patient did not receive any further dose of zoledronic acid, proteinuria reoccurred, although at a lower level when the investigational drug was reintroduced at the same dose. Renal function remained normal. The patient received two further cycles with lower doses, without recurrence of proteinuria. These findings suggest that this type of integrin antibody may induce transient urinary excretion of protein in a dose dependent manner without adversely affecting renal function.