Bingileki F Lwezaula1,2,3, Oluwatoyin I Ameh4, Udeme E Ekrikpo5, Francois Cj Botha6,7, Ugochi S Okpechi-Samuel8, Nicola Wearne1,2, Pierre Ronco9, Aminu K Bello10, Ikechi G Okpechi11,12,13. 1. Division of Nephrology and hypertension, University of Cape Town, Cape Town, South Africa. 2. Kidney and Hypertension Research Unit, University of Cape Town, Cape Town, South Africa. 3. Mount Meru Regional Referral Hospital, Arusha, Tanzania. 4. Division of Nephrology, Zenith Medical & Kidney Centre, Gudu, Abuja, Nigeria. 5. Department of Medicine, University of Uyo, Uyo, Nigeria. 6. Pathcare Laboratories, George, South Africa. 7. Division of Anatomical pathology, University of Cape Town, Cape Town, South Africa. 8. Department of Internal Medicine, Federal Medical Centre, Jabi, Abuja, Nigeria. 9. Department of Nephrology and Dialysis, Assistance Publique-Hôpitaux de Paris, Tenon Hospital, Paris, France. 10. Department of Medicine, University of Alberta, Edmonton, Canada. 11. Division of Nephrology and hypertension, University of Cape Town, Cape Town, South Africa. Ikechi.Okpechi@uct.ac.za. 12. Kidney and Hypertension Research Unit, University of Cape Town, Cape Town, South Africa. Ikechi.Okpechi@uct.ac.za. 13. Department of Medicine, University of Alberta, Edmonton, Canada. Ikechi.Okpechi@uct.ac.za.
Abstract
BACKGROUND: Serum and tissue-based tests using phospholipase A2 receptor 1 (PLA2R) and thrombospondin type-1 domain containing 7A (THSD7A) are established immune biomarkers for the diagnosis of primary membranous nephropathy (PMN). This study assessed the diagnostic performance of these biomarkers in the diagnosis of PMN in South Africans. METHODS: This was a cross-sectional analysis from a single centre in Cape Town, South Africa. Relevant biodata was collected from all patients. Histology, including slides for PLA2R and THSD7A were processed and assessed by typical microscopic and immunohistochemical features. Biopsy tissues of patients with membranous lupus nephritis (LN-V) and diabetic nephropathy (DN) were used as controls. The diagnostic accuracy for diagnosis of PMN using positive PLA2R and THSD7A were evaluated. RESULTS: Of the 88 patients included, 41 had PMN with a mean age of 44.5 ± 17.5 years and 61.0% were female. Histologically, PLA2R and THSD7A were only positive in the PMN group (51.2% and 4.9%, respectively) but negative in both control groups. The sensitivity of PLA2R and THSD7A for identifying PMN was 51.2% and 4.9%, respectively. The sensitivity of both tests together was 53.7% while the specificity and positive predictive values (PPV) for any of the tests (alone or in combination) was 100%. There was no difference in the sensitivity and specificity when using PLA2R alone compared to combining the two tests (p=0.32). CONCLUSION: Glomerular staining of PLA2R and THSD7A could have potential diagnostic values in South Africans. This has implications on how immunotherapies can be initiated and used in these settings.
BACKGROUND: Serum and tissue-based tests using phospholipase A2 receptor 1 (PLA2R) and thrombospondin type-1 domain containing 7A (THSD7A) are established immune biomarkers for the diagnosis of primary membranous nephropathy (PMN). This study assessed the diagnostic performance of these biomarkers in the diagnosis of PMN in South Africans. METHODS: This was a cross-sectional analysis from a single centre in Cape Town, South Africa. Relevant biodata was collected from all patients. Histology, including slides for PLA2R and THSD7A were processed and assessed by typical microscopic and immunohistochemical features. Biopsy tissues of patients with membranous lupus nephritis (LN-V) and diabetic nephropathy (DN) were used as controls. The diagnostic accuracy for diagnosis of PMN using positive PLA2R and THSD7A were evaluated. RESULTS: Of the 88 patients included, 41 had PMN with a mean age of 44.5 ± 17.5 years and 61.0% were female. Histologically, PLA2R and THSD7A were only positive in the PMN group (51.2% and 4.9%, respectively) but negative in both control groups. The sensitivity of PLA2R and THSD7A for identifying PMN was 51.2% and 4.9%, respectively. The sensitivity of both tests together was 53.7% while the specificity and positive predictive values (PPV) for any of the tests (alone or in combination) was 100%. There was no difference in the sensitivity and specificity when using PLA2R alone compared to combining the two tests (p=0.32). CONCLUSION: Glomerular staining of PLA2R and THSD7A could have potential diagnostic values in South Africans. This has implications on how immunotherapies can be initiated and used in these settings.
Authors: Sanjeev Sethi; Benjamin J Madden; Hanna Debiec; M Cristine Charlesworth; LouAnn Gross; Aishwarya Ravindran; Amber M Hummel; Ulrich Specks; Fernando C Fervenza; Pierre Ronco Journal: J Am Soc Nephrol Date: 2019-05-06 Impact factor: 10.121
Authors: Keng Thye Woo; Choong Meng Chan; Cynthia Lim; Jason Choo; Yok Mooi Chin; Esther Wei Ling Teng; Irene Mok; Jia Liang Kwek; Alwin H L Loh; Hui Lin Choong; Han Kim Tan; Grace S L Lee; Evan Lee; Kok Seng Wong; Puay Hoon Tan; Marjorie Foo Journal: Kidney Dis (Basel) Date: 2019-06-11
Authors: Ikechi G Okpechi; Oluwatoyin I Ameh; Aminu K Bello; Pierre Ronco; Charles R Swanepoel; Andre P Kengne Journal: PLoS One Date: 2016-03-24 Impact factor: 3.240
Authors: Sanjeev Sethi; Hanna Debiec; Benjamin Madden; Marina Vivarelli; M Cristine Charlesworth; Aishwarya Ravindran; LouAnn Gross; Tim Ulinski; David Buob; Cheryl L Tran; Francesco Emma; Francesca Diomedi-Camassei; Fernando C Fervenza; Pierre Ronco Journal: Kidney Int Date: 2020-06-11 Impact factor: 10.612