IgA nephropathy flare-up with AKI; Acute kidney injury; This literature-non-study case was reported in a literature article and describes the occurrence of IGA NEPHROPATHY (IgA nephropathy flare-up with AKI) and ACUTE KIDNEY INJURY (Acute kidney injury) in a 54-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination.       The patient's past medical history included Streptococcal infection. Concurrent medical conditions included Obesity (BMI 31.6), Hypertension, GERD and IgA nephropathy (after strep throat infection that was diagnosed with renal biopsy) since 2006. Concomitant products included ENALAPRIL, HYDROCHLOROTHIAZIDE and PROPRANOLOL for an unknown indication.   On an unknown date, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On an unknown date, received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On an unknown date,  after starting mRNA-1273 (Moderna COVID-19 Vaccine), the patient experienced IGA NEPHROPATHY (IgA nephropathy flare-up with AKI) (seriousness criterion medically significant) and ACUTE KIDNEY INJURY (Acute kidney injury) (seriousness criterion medically significant). The patient was treated with PREDNISONE for IgA nephropathy, at a dose of 60 mg once a day. At the time of the report, IGA NEPHROPATHY (IgA nephropathy flare-up with AKI) and ACUTE KIDNEY INJURY (Acute kidney injury) was resolving.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Biopsy kidney: abnormal (abnormal) Repeat kidney biopsy showed IgA mesangial deposition, focal segmental and focal global glomerulosclerosis, mild interstitial fibrosis and tubular atrophy, and mild arteriolar hyalinosis. and abnormal (abnormal) IgAN. On an unknown date, Blood creatinine: 3.04 3.04 one week after second dose of vaccine, 1.7 after she was started on prednisone creatinine level started getting better. In 3 weeks Cr level was down to 1.7 and 1.2 (abnormal) Baseline creatinine level was 1.2. On an unknown date, Blood urine: 3+ Positive for 3+ blood and 3+ (abnormal) urinalysis showed 3+ blood. On an unknown date, Protein urine: 1+ urinalysis showed 1+ protein and 2+ (Positive) Positive for 2+ protein. On an unknown date, Red blood cells urine: 50/hpf RBC 50/HPF and 15/hpf RBC 15/HPF. On an unknown date, Ultrasound kidney: normal (normal) Unremarkable. On an unknown date, Urine protein/creatinine ratio: 1.03 The total urine protein to Cr ratio was 1.03 and 0.67 after receiving the second Moderna mRNA-1273 vaccine, the total urine protein to Cr ratio was 0.67.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter considered IGA NEPHROPATHY (IgA nephropathy flare-up with AKI) and ACUTE KIDNEY INJURY (Acute kidney injury) to be possibly related.    Patient developed gross hematuria two days after receiving the second Moderna mRNA-1273 vaccine, which resolved in 2 days  Author discussed that this is the first reported case of biopsy-proven IgAN flare-up after SARS-CoV-2 vaccination that caused AKI. Corticosteroid is an effective treatment, promptly improving Cr. IgAN exacerbation after SARs-Cov-2 vaccination should be closely monitored for frequency and consequence to further elucidate AEFI of the novel vaccine.  Company Comment: This case concerns a 54-year-old female patient, with medical history of IgA nephropathy, hypertension and obesity, who experienced the serious unexpected event of IgA NEPROPATHY (reported as IgA nephropathy flare-up) and the serious unexpected AESI of ACUTE KIDNEY INJURY. The events occurred on an unknown date, approximately 2 days after receiving the second dose of the Moderna COVID 19 Vaccine. The rechallenge is not applicable since no information about further dosing has been provided. Two days after receiving de second dose of the Moderna COVID 19 vaccine, the patient experienced hematuria and worsening on her baseline renal function. Renal kidney biopsy confirmed the diagnosis of IgA neophropathy flare up. Patient was started on prednisone and her renal function started improving. Patient's medical history of IgA nephropathy, hypertension and obesity remains as a confounder. The benefit-risk relationship of the Moderna COVID 19 vaccine is not affected by this report.; Sender's Comments: This case concerns a 54-year-old female patient, with medical history of IgA nephropathy, hypertension and obesity, who experienced the serious unexpected event of IgA NEPROPATHY (reported as IgA nephropathy flare-up) and the serious unexpected AESI of ACUTE KIDNEY INJURY. The events occurred on an unknown date, approximately 2 days after receiving the second dose of the Moderna COVID 19 Vaccine. The rechallenge is not applicable since no information about further dosing has been provided. Two days after receiving de second dose of the Moderna COVID 19 vaccine, the patient experienced hematuria and worsening on her baseline renal function. Renal kidney biopsy confirmed the diagnosis of IgA neophropathy flare up. Patient was started on prednisone and her renal function started improving. Patient's medical history of IgA nephropathy, hypertension and obesity remains as a confounder. The benefit-risk relationship of the Moderna COVID 19 vaccine is not affected by this report.