Membranous Nephropathy with an Enhanced Granular Expression of Thrombospondin Type-1 Domain-containing 7A in a Pregnant Woman

Abstract

A 30-year-old woman with proteinuria first noted at 26 weeks of gestation was admitted to undergo further evaluation. A renal biopsy revealed membranous nephropathy (MN). There was no evidence of any secondary MN. Prednisolone was initiated 6 months after delivery. Four months later, her urine protein became negative. Enhanced granular staining for thrombospondin type-1 domain-containing 7A (THSD7A) in the glomeruli was retrospectively detected in a biopsy specimen. A literature review revealed that 60% of cases of THSD7A-related MN occurred in women of childbearing age. Therefore, THSD7A-related MN should be considered in female patients presenting with idiopathic MN in childbearing age.

Novel ELISA for thrombospondin type 1 domain-containing 7A autoantibodies in membranous nephropathy

“…Another cause of MN may be associated with pregnancy and preeclampsia, [70][71][72][73] including recent observations for THSD7A-associated MN. 74,75 In line with this hypothesis, we observed a significant subgroup of young THSD7A-positive female patients (before menopause) ( Figure 4b) in our cohort but we could not find evidence of a relationship between MN and pregnancy or preeclampsia.…”

Prediagnostic Appearance of Thrombospondin Type-1 Domain 7A Autoantibodies in Membranous Nephropathy

“…Interestingly in the pilot cohort, two cases of THSD7Aassociated MN were diagnosed shortly after pregnancy. THSD7A-associated MN during pregnancy has been reported (25). Since THSD7A is expressed in placental vasculature and umbilical vein endothelial cells ( 13), these sites could be a source of extrarenal expression leading to autoantibody production, but this is purely speculation.…”