Thrombospondin Type-1 Domain-Containing 7A Antibodies, Serum

Casandra

Casandra Test Code MC94014Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID THSD7CPT Code 86255

Thrombospondin Type-1 Domain-Containing 7A Antibodies, Serum

Clinical Use

Use

The test is useful for distinguishing primary from secondary membranous nephropathy cases with antibodies against THSD7A. Recently, autoantibodies against phospholipase A2 receptor (PLA2R) in the kidney were determined to be the major target antigen for patients with idiopathic/primary membranous nephropathy. Approximately 70% of patients with primary MN circulate anti-PLA2R antibodies, and in the remaining 30% who are PLA2R-negative, anti-thrombospondin type-1 domain-containing 7A (THSD7A) was shown to have approximately a 10% prevalence (or about 3% of all primary MN patients). THSD7A has been described as a potential tumor antigen, suggesting that THSD7A-positive patients merit a thorough cancer screening.

Special Instructions

This test should not be used as a stand-alone test but as an adjunct to other clinical information. The determination of the antibody titer has a high predictive value with respect to clinical remission, relapse, or risk assessment after kidney transplantation.

Limitations

A diagnosis of primary or secondary membranous nephropathy (MN) should not be made based on a single test result. The clinical symptoms, results on physical examination, and laboratory tests (eg, serological tests), when appropriate, should always be taken into account when considering the diagnosis of primary versus secondary MN. Absence of circulating autoantibodies does not rule out a diagnosis of primary MN.

Test Details

New York Approved