Poster Presentation - SOMANZ ASM Society of Obstetric Medicine of Australia and New Zealand ASM 2023

Phospholipase A2 receptor antibody positive membranous nephropathy in pregnancy: a case report (#64)

Alessandra Orsillo 1 2 , Nishanta Tangirala 1 2 3 , Mark Morton 2 4 , Shilpa Jesudason 1 2
  1. Central and Northern Adelaide Renal and Transplantation Service, Adelaide, SA, Australia
  2. University of Adelaide, Adelaide, South Australia, Australia
  3. Women's and Children's Hospital Foundation, North Adelaide, South Australia
  4. Women's and Children's Hospital, Adelaide, South Australia

Introduction:

Primary membranous nephropathy is a common form of nephrotic syndrome worldwide. It is an uncommon yet important condition in pregnancy. The identification of pathogenic autoantibodies has been transformative to diagnosis and management of primary membranous nephropathy, with 70% of cases associated with antibodies to phospholipase A2 receptor (PLA2R) on podocytes1.  There are limited reports of cases of membranous nephropathy in pregnancy, and in particular, the utility of PLA2R in pregnancy2,3,4,5.

Case summary:

We present a case of a 35 year old woman from Pakistan who has a history of nephrotic syndrome diagnosed at age 18 overseas, and treated at the time. In Australia, she presented in 2020 to the renal service after an early first trimester spontaneous abortion with a relapse of nephrotic syndrome. Biopsy confirmed membranous nephropathy and a PLA2R of 115IU/mL (normal <13.9IU/mL). She was referred to an obstetric nephrology service for pre-pregnancy counselling and advised to delay pregnancy until disease control was established. Disease remission was not achieved through first line management, and she was subsequently given two doses of rituximab.  She fell pregnant 3 months following rituximab despite counselling against this. She was managed closely by a multidisciplinary team of obstetric nephrology, obstetric medicine and maternal-fetal medicine services. In the first trimester, there was evidence of disease remission, clinically and biochemically, with low PLA2R (2 IU/ml), suppressed B cells and less than 1g/proteinuria/24 hours. However during the second trimester she became increasingly nephrotic with hypertension and peripheral oedema. The PLA2R increased to 51.2 IU/ml at 20 weeks’ gestation with an associated 7g/proteinuria/24hours. Tacrolimus was initiated to regain disease control and by 30 weeks gestation there was a reduction in proteinuria and antibody levels. However, with progressive hypertension and concerns for pre-eclampsia, the patient was admitted to hospital and delivered a healthy male infant via emergency caesarean section at 34 weeks gestation. There was evidence of trans-placental transfer of PLA2R antibody, with levels of 15.2 IU/mL in the infant, although he had only mild proteinuria which spontaneously resolved and no features of overt nephrotic syndrome. There have so far been no detected adverse infant outcomes from rituximab exposure.

 

Conclusion

This case illustrates the utility of PLA2R in pregnancy. We found PLA2R titres reflected disease activity of membranous nephropathy with associated rise in proteinuria, creatinine and hypertension. Maternal-fetal transfer of PLA2R has been demonstrated in this case, however, had no clinical consequences to the neonate. 

 

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  2. 2. Liu Z ning, Cui Z, He Y dong, Zhang Y miao, Wang F, Wang X, et al. Membranous Nephropathy in Pregnancy. Am J Nephrol. 2020;51(4):304–17. 3 3.
  3. 3. Uchino E, Takada D, Mogami H, Matsubara T, Tsukamoto T, Yanagita M. Membranous nephropathy associated with pregnancy: an anti-phospholipase A2 receptor antibody-positive case report. CEN Case Rep. 2018 Jan 18;7(1):101–6. 4
  4. 4. Al-Rabadi L, Ayalon R, Bonegio RG, Ballard JE, Fujii AM, Henderson J, et al. Pregnancy in a Patient With Primary Membranous Nephropathy and Circulating Anti-PLA2R Antibodies: A Case Report. Am J Kidney Dis. 2016 May;67(5):775–
  5. 5.. Glomerular diseases in pregnancy: pragmatic recommendations for clinical management - Kidney International [Internet]. [cited 2023 Jul 6]. Available from: https://www.kidney-international.org/article/S0085-2538(22)01015-8/fulltext