primary membranous nephropathy flare; This literature-non-study case was reported in a literature article and describes the occurrence of GLOMERULONEPHRITIS MEMBRANOUS (primary membranous nephropathy flare) in a 62-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination.   LITERATURE REFERENCE: Primary membranous nephropathy flare after COVID-19 vaccination.     The patient's past medical history included Proteinuria (7029 mg/24hr with PLA2R Ab 128 RU/mL in October 2018) in August 2018, Modified radical mastectomy in September 2018 and Chemotherapy (after which PLA2R Ab decreased to <2 RU/mL in February 2019) in November 2018. Previously administered products included for Metastatic breast cancer: anastrazole (T3N3M1 ER/PR positive HER-2 negative metastatic left breast invasive ductal carcinoma.). Past adverse reactions to the above products included No adverse event with anastrazole. Concurrent medical conditions included Hypertension, Hyperlipidemia, Membranous nephropathy and Invasive ductal breast carcinoma stage III.   In January 2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. In February 2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. In March 2021,  after starting mRNA-1273 (Moderna COVID-19 Vaccine), the patient experienced GLOMERULONEPHRITIS MEMBRANOUS (primary membranous nephropathy flare) (seriousness criterion medically significant). The patient was treated with RITUXIMAB in May 2021 for Membranous nephropathy, at an unspecified dose and frequency; LISINOPRIL in May 2021 for Membranous nephropathy, at an unspecified dose and frequency and FUROSEMIDE in May 2021 for Membranous nephropathy, at an unspecified dose and frequency. At the time of the report, GLOMERULONEPHRITIS MEMBRANOUS (primary membranous nephropathy flare) outcome was unknown. Possible    DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In April 2019, Immunology test: mn flare (abnormal) abnormal, MN Flare. In April 2019, Urine protein/creatinine ratio: 1094 mg/g cr urine protein/Cr ratio (UPCR) decreased to 1094 mg/g Cr. In 2021, Biopsy kidney: abnormal Renal biopsy showed immune complex-mediated glomerulopathy with positive PLA2R, consistent with primary MN stage II-III. . Glomerular basement membrane deposits were strongly positive for IgG4.. In 2021, Creatinine urine: 1.6 mg/dl 1.6 mg/dL. In 2021, Microscopy: abnormal Electron microscopy showed numerous subepithelial and occasional intramembranous electron-dense immune-type deposits. In 2021, Protein urine: 11.2 g 11.2 g. In 2021, Urine analysis: >1000 protein >1000 protein. In 2021, Urine protein/creatinine ratio: 8671 mg/g cr 8671 mg/g Cr.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter considered GLOMERULONEPHRITIS MEMBRANOUS (primary membranous nephropathy flare) to be possibly related.    Patient developed nephrotic syndrome after receiving her second mRNA-1273 COVID-19 vaccine with positive PLA2R Ab by ELISA suggesting MN flare.  Patient developed nephrotic syndrome after receiving her second mRNA-1273 COVID-19 vaccine with positive PLA2R Ab by ELISA suggesting MN flare.  Patient had PLA2R Ab 128 RU/mL in October 2018. PLA2R Ab  was 787 RU/mL in May 2021.  This literature non-study case concerns a 62-year-old female patient  with stage III invasive ductal carcinoma with relevant concurrent conditions primary membranous nephritis, hypertension and hyperlipidaemia who experienced serious unexpected events of glomerulonephritis membranous, reported as primary membranous nephropathy flare. The event occurred approximately two weeks after the second dose of the Moderna COVID-19 vaccine. The patient present with bilateral leg edema, dyspnea, bilateral pleural effusion and proteinuria, 2 weeks after COVID-19 vaccination. She had previous proteinuria of 7029 mg/24hr in August 2018 with PLA2R Ab 128 RU/mL in October 2018. The patient received lisinopril and furosemide followed by rituximab as a corrective treatment for the event. Rechallenge was not applicable as the event occurred after the second dose so no rechallenge was done and thus, recurrence was not applicable. Patient's concurrent condition are possible confounders. The event was considered possibly related per reporter's assessment. The benefit-risk relationship of product is not affected by this report.   Reporter did not allow further contact   Most recent FOLLOW-UP information incorporated above includes: On 11-Nov-2021: Follow up received by safety on 11-NOV-2021 has Email with FTA received from SARA team and contain significant information like author names; Sender's Comments: This literature non-study case concerns a 62-year-old female patient  with stage III invasive ductal carcinoma with relevant concurrent conditions primary membranous nephritis, hypertension and hyperlipidaemia who experienced serious unexpected events of glomerulonephritis membranous, reported as primary membranous nephropathy flare. The event occurred approximately two weeks after the second dose of the Moderna COVID-19 vaccine. The patient present with bilateral leg edema, dyspnea, bilateral pleural effusion and proteinuria, 2 weeks after COVID-19 vaccination. She had previous proteinuria of 7029 mg/24hr in August 2018 with PLA2R Ab 128 RU/mL in October 2018. The patient received lisinopril and furosemide followed by rituximab as a corrective treatment for the event. Rechallenge was not applicable as the event occurred after the second dose so no rechallenge was done and thus, recurrence was not applicable. Patient's concurrent condition are possible confounders. The event was considered possibly related per reporter's assessment. The benefit-risk relationship of product is not affected by this report