THROMBOTIC THROMBOCYTOPENIC PURPURA; ALTERED MENTAL STATUS; ACUTE KIDNEY INJURY; LIVER FUNCTION TEST ABNORMAL; EMESIS; This spontaneous report was received from literature dated  2021 May 02; 11-2. This report concerned a 62 year old female.  The patient's height and weight were not reported. The patient's concurrent conditions included hypertension, hyperlipidemia, hypothyroidism and gastroesophageal reflux disease.  On an unspecified date, the patient received COVID-19 vaccine Ad26.CoV2.S (suspension for injection, intramuscular, batch number unknown), dose, vaccination date and site of administration not reported, for prophylactic vaccination. The batch number was not reported and has been requested. No concomitant medications were reported.  On an unspecified date (37 days post vaccination), the patient experienced thrombotic thrombocytopenic purpura (TTP), altered mental status, acute kidney injury, liver function test abnormal, and emesis, and was hospitalized (date unspecified).  It was reported by emergency medical services that the patient was found altered in her bathroom combative and covered in faeces. The patient was unable to converse or provide any history. The patient's family reported she was last seen normal around 21:00 hours on an unspecified date and around midnight they heard a loud sound upstairs and went up to find the patient's room covered in emesis, faeces on the floor and she had torn her room apart and ripped things off the walls. It was reported that before going upstairs for bed she was in her normal state of good health and had eaten dinner with her family. The patient appeared altered, unwell and was spontaneously moving all extremities. Physical examination revealed temperature of 36.6 degrees Celsius, blood pressure of 154/131 mmHg, a pulse rate of 87 beats per minute, a respiratory rate of 32 breaths per minute, and pulse oximetry of 96% on room air. There were no signs of trauma; her pupils were 3 mm, equal and reactive. She had a full passive range of motion of her neck, normal heart sounds, tachypnoea with a few scattered wheezes, Glasgow Coma Scale of 12 and skin revealed scattered petechiae. Laboratory workup revealed the following abnormal results: elevated white blood cell count 19.25 k/mcL, absolute neutrophils 15.59 k/mcL, lactate 4 mmol/L, procalcitonin 13.21 ng/mL, and C-reactive protein 6.4 mg/dL. Low fibrinogen 120 mg/dL and platelets 29 k/mcL. Urinalysis revealed large haemoglobin and 11 - 25 red blood cells per high powered field. Other tests that included COVID-19 testing, drug screen, haptoglobin, prothrombin time and international normalized ratio were all normal. A complete metabolic was not able to be collected in the emergency department (ED) due to persistently haemolyzed specimens even from the central venous catheter. Computerized tomography (CT) of the brain and cervical spine revealed no acute abnormalities. Chest and pelvis x-ray were normal.  The patient had an episode of emesis and there was a concern for aspiration. She was intubated for airway protection and admitted to the medical intensive care unit (ICU). During admission, haematology, neurology and infectious disease were consulted. She was found in the ICU to have acute kidney injury with a blood urea nitrogen of 26 mg/dL and creatinine of 2.19 mg/dL (NR not provided). On an unspecified date, (day 1 of the hospital) haptoglobin became low at below 10 mg/dL. On hospital day 2, her platelet count was reported as "11,000 k/uL", blood urea (BUN) was 66 mg/dL and creatinine was 6 mg/dL. The patient's liver function tests were abnormal with aspartate aminotransferase (AST) of 982 U/L and alanine aminotransferase (ALT) of 231 U/L. Her fibrinogen increased to 619 mg/dL, lactate hydrogenase was greater than 2500 U/L, and her high-sensitivity troponin was found to be 2408 ng/L. Haemoglobin had also dropped from 14 g/dL upon admission to 8.2 g/dL on day 2 of her hospitalisation (NR not provided for all). Her anti-platelet factor 4 test, double-stranded DNA antibody test, and "complement component 3" were normal. Direct coombs was negative and the patient was platelet factor 4 negative. "Compliment component 4" was slightly low at 12 mg/dL and "ADAMTS13" activity was less than 12%. Once in the medical ICU, plasma exchange and high dose steroids were initiated due to worsening platelets. When her haptoglobin and "ADAMTS13" results were abnormal, the diagnosis of TTP was confirmed. While hospitalized the patient required hemodialysis, packed red blood cells for anaemia, plasma exchange, and 10,000 mg of methylprednisolone daily. The action taken with COVID-19 vaccine Ad26.CoV2.S was not applicable. The outcomes of the thrombotic thrombocytopenic purpura, liver function test abnormal, emesis and acute kidney injury were not reported.  This report was serious (Hospitalization Caused / Prolonged).; Sender's Comments: V0:  This report from the literature describes a 62-year-old female who developed thrombotic thrombocytopenic purpura (TTP) 37 days after receiving the Janssen COVID-19 vaccine.  She suddenly developed  emesis and severe mental status changes; physical examination was significant for a blood pressure of 154/31, tachypnea, and scattered petechiae. Initial laboratory evaluation was significant for a platelet count of 29 k/mcl, hemoglobinuria, a BUN of 26 mg/dl and creatinine of 2.19 mg/dl. Computerized tomography of the brain revealed no abnormalities.  She was intubated for airway protection and admitted to the intensive care unit. Follow-up labs included: haptoglobin low at 10 mg/dl, BUN 66 mg/dl, creatinine 6 mg/dl, elevated hepatic enzymes, anti-platelet factor 4  negative, and ADAMTS13 activity less than 12% (abnormal).  Based on the low haptoglobin and ADAMTS13 activity level, a diagnosis of TTP was made.  She underwent hemodialysis, plasma exchange, red blood cell transfusions, and daily methylprednisolone administration.  The outcome was not reported.  Thrombotic thrombocytopenic purpura is not a labeled event for the Janssen COVID-19 vaccine; however, based on the temporal relationship of the events to vaccination, a relationship with the vaccine cannot be ruled out.  The relationship is considered indeterminate