key: cord-0741329-q6580cyv authors: Mayordomo-Colunga, Juan; Vivanco-Allende, Ana; López-Alonso, Inés; López-Martínez, Cecilia; Fernández-Vega, Iván; Gil-Peña, Helena; Rey, Corsino title: SARS-CoV-2 SPIKE PROTEIN IN INTESTINAL CELLS OF A PATIENT WITH COVID-19 MULTISYSTEM INFLAMMATORY SYNDROME date: 2021-11-27 journal: J Pediatr DOI: 10.1016/j.jpeds.2021.11.058 sha: f94eead1f305334f9790de50f6cd34f5c6a3a976 doc_id: 741329 cord_uid: q6580cyv A previously healthy 12-year-old boy had severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related multisystem inflammatory syndrome (MIS-C) that was rapidly fatal. Autopsy revealed the presence of a large intracardiac thrombus. SARS-CoV-2 spike protein was detected in intestinal cells, supporting the hypothesis that viral presence in the gut may be related to the immunologic response of MIS-C. A previously healthy 12-year-old boy had severe SARS-CoV-2 related multisystem inflammatory syndrome (MIS-C) that was rapidly fatal. Autopsy revealed the presence of a large intracardiac thrombus. SARS-CoV-2 spike protein was detected in intestinal cells, supporting the hypothesis that viral presence in the gut may be related to the immunologic response of MIS-C. Multisystem inflammatory syndrome associated with SARS-CoV-2 infection (MIS-C) was described during the first SARS-CoV-2 pandemic wave in Europe 1 . Days or weeks after SARS-CoV-2 infection or exposure, some children (predominantly school-aged) develop this life-threatening disease 2 Patients present with fever, gastrointestinal symptoms, high inflammatory markers and cardiogenic shock 2, 4, 5 . Although the pathophysiology remains unclear, MIS-C encompasses cytokine-mediated hyperinflammation 3 Requirement for intensive care is reported in 50 to 80% of cases of MIS-C, and the fatality rate is reported to be 0-2% 2, [5] [6] [7] [8] [9] In the three reported pediatric autopsies, SARS-CoV-2 was reported in several tissues and the existence of the virus in intestinal cells was shown in one child 10 . Here, we present a case of overwhelming MIS-C in a previously healthy child, providing relevant information about autopsy findings and histologic, immunohistochemical and immunofluorescent analysis for SARS-CoV-2. A 12-year-old boy with no significant past medical history presented with symptoms that began 3 days before admission consisting of malaise, fever, maculopapular rash and diffuse abdominal pain, with diarrhea. Two family members had tested positive for J o u r n a l P r e -p r o o f SARS-CoV-2 by reverse-transcriptase polymerase chain reaction (RT-PCR) on nasopharyngeal swab 6 weeks prior. At presentation the patient tested negative RT-PCR in nasopharyngeal swab and positive for serum SARS-CoV-2 immunoglobulin G. Abdominal ultrasound showed inflammation of the terminal ileum and peritoneal free fluid, not consistent with appendicitis; amoxicillin-clavulanate acid and intravenous fluids were begun. Microscopic urinalysis showed no leukocytes or nitrates, although a sample was sent for culture, revealing the presence of 50000 CFU/mL of Providencia stuartii. Blood cultures as well as subsequent tracheal aspirate cultures were negative. A few hours after admission he developed fluid-refractory shock and was transferred to the pediatric intensive care unit (PICU). Initial tests revealed lymphopenia and increased levels of inflammatory markers (Table I ; available at www.jpeds.com). Dopamine was begun, he was intubated and was subsequently treated with adrenaline and milrinone. Antibiotic coverage was changed to cefotaxime and clindamycin. MIS-C was considered a possible diagnosis and the patient was given corticosteroids (methylprednisolone 50 mg/12 hours, ~1.7 mg/kg/day). An echocardiogram performed after intubation showed a slight reduction of left ventricular ejection fraction (~60%), with no other obvious abnormalities. Blood tests showed progressive increase of inflammatory markers ( Table I) . The following day the child developed fever up to 42.1ºC, and was not responding to intravenous immunoglobulin and a methyl-prednisolone pulse (one gram), and required addition of noradrenaline to maintain blood pressure. Low weight molecular heparin was started and antibiotic therapy was changed to vancomycin and meropenem. Serum creatinine, procalcitonin, D-dimer, lactate dehydrogenase and cardiac markers showed an abrupt elevation ( Table I) At autopsy macroscopically, the heart was non-dilated and had a 4x1 cm thrombus in the right ventricle, encircling one papillary muscle (Figure 1 , A; available at www.jpeds.com). Other macroscopic findings are shown in Figure 1 -(available at www.jpeds.com) and in Table II . Disseminated intravascular coagulopathy (DIC) was identified in most organs. Severe inflammation was found in the intestine and the heart, and hemophagocytosis was prevalent in the bone marrow ( Figure 2 ; available at www.jpeds.com)). Complement C4d deposits were found in microvessels of the intestine, skin, liver and heart ( Figure 3 ; available at www.jpeds.com), but not in other organs. To perform immunofluorescence, tissue slices were deparaffinated and antigens Our case has unique features, mainly the overwhelming evolution in less than 48 hours, the refractory hyperpyrexia and the cardiac thrombus. The child fulfilled all the current criteria for MIS-C, but as many clinical features are common with a bacterial septic shock, broad-spectrum antibiotics were used. The formation of a large cardiac thrombus in our case is noteworthy as this has been an uncommon complication in MIS-C 12 . Arrythmia has been reported to be one of the most frequent cardiovascular complications in MIS-C 7 , ventricular tachycardia has also been reported 9 . Histologic examination of most organs revealed frequent extensive thrombosis and areas of hemorrhage, findings that are not distinguishable from other causes of DIC. Duarte-Neto,et al also reported thrombi in most organs of patients with MIS-C 10 . inflammation was present mainly in the heart and the intestine, and inflammation was described in most organs in the Duarte-Neto et al case series 10 . We cannot exclude that the short course from the onset of symptoms to death of our patient could be related to limited sites of inflammation. However, as immune activation may be primarily responsible for tissue damage, there could be a discrepancy between presence of virus and tissue inflammation, as described in adults with fatal COVID-19 13 . J o u r n a l P r e -p r o o f MIS-C has some clinical similarities with Kawasaki disease, although they appear to be distinct entities 14 . Histologically, systemic vasculitis is the main feature in KD, affecting the coronary arteries in most patients. Furthermore, inflammation is present in most organs and tissues in fatal KD 15 . By contrast, in our case, inflammation was confined to the heart and the gut, and vasculitis was not found. In our case and in other reported fatal MIS-C cases, infiltration of coronary arteries was not found 10, 11 . Neither diffuse alveolar damage nor hyaline membrane formation was present in our case or in the reported MIS-C cases, except for some foci of exudative diffuse alveolar damage in one child 10 . These findings are consistent with the lack of respiratory symptoms at presentation of our patient, and the relative paucity of respiratory involvement described in MIS-C 16 . The lungs in our case and in reported cases showed congestion, edema, foci of hemorrhage and thrombi 10 . Conversely, the lungs in two patients with a pulmonary form of COVID-19 exhibited pneumonia and diffuse alveolar damage 13, 17 . , the heart in our patient showed myocarditis with significant lymphocyte and macrophage infiltrate. In the other reported autopsies of patients with MIS-C, significant cardiac involvement was seen, with areas of necrosis in all. In contrast, in autopsies of two patients with acute COVID-19 infection only myocardial interstitial edema was seen 10 18 . Similarly, it has been described that the gut serves as a nidus for SARS-CoV-2 in adults 21 . In our child SARS-CoV-2 protein S was not observed in the lung or the heart, and in the previous report SARS-CoV-2 particles were demonstrated in the heart and lungs of all 3 children and also in liver, kidneys, spleen, brain and sweat glands 10 Erythrocyte aggregates obstructing the lumen of capillaries without platelet or fibrinoid material, fibrin thrombus and shrinkage of capillary loops in glomeruli. Edematous cecum mucosa. A 9 x 2.5 cm lymphadenopathy was found next to the cecum, which on cut sections revealed extensive areas of hemorrhage. Numerous infiltrating plasma cells and lymphocytes with interstitial oedema in the lamina propria. Intense oedema of submucosa with mild infiltration of immune cells. Significant deposits of complement C4d in the microvasculature. Arteriolar microthrombi. Focal macrovesicular steatosis, nuclear glycogen accumulation in hepatocytes, moderate zone 3 sinusoidal dilatation with extensive centrilobular necrosis (submassive hepatic necrosis). No other macroscopic significant findings in other parts of the gastrointestinal system. Oesophagus No significant changes. Partial epithelial degeneration, necrosis and shedding of the gastric mucosa. Dilatation and congestion of small blood vessels. Moderate oedema of submucosa with mild infiltration of immune cells (as lymphocytes, monocytes and plasma cells). Pancreas Not significant changes. Non dilated heart showing a 4x1 cm thrombus in the right ventricle, encircling one papillary muscle. Coronary arteries were patent. Significant interstitial oedema and presence of inflammatory cells. Foci of lymphocytic inflammation CD3+. Presence of diffuse mobilization and infiltration by CD68+ macrophages in the myocardium. Significant deposits of complement C4d in the microvasculature. Coronary arteries showed no signs of vasculitis, microscopy was normal. No significant changes. Guidance: Paediatric multisystem inflammatory syndrome temporally associated with COVID-19 Multisystem Inflammatory Syndrome in Children: An International Survey Mapping Systemic Inflammation and Antibody Responses in Multisystem Inflammatory Syndrome in Children (MIS-C) Characteristics and Outcomes of US Children and Adolescents With Multisystem Inflammatory Syndrome in Children (MIS-C) Compared With Severe Acute COVID-19 Peripheral immunophenotypes in children with multisystem inflammatory syndrome associated with SARS-CoV-2 infection Acute Cardiovascular Manifestations in 286 Children With Multisystem Inflammatory Syndrome Associated With COVID-19 Infection in Europe Severe manifestations of SARS-CoV-2 in children and adolescents: from COVID-19 pneumonia to multisystem inflammatory syndrome: a multicentre study in pediatric intensive care units in Spain Clinical Characteristics of 58 Children With a Pediatric Inflammatory Multisystem Syndrome Temporally Associated With SARS-CoV-2 An autopsy study of the spectrum of severe COVID-19 in children: From SARS to different phenotypes of MIS-C Vander Heide RS. Cardiac Endotheliitis and Multisystem Inflammatory Syndrome After COVID-19 Report: Acute Intracardiac Thrombosis in Children With Coronavirus Disease 2019 (COVID-19) Tissue-Specific Immunopathology in Fatal COVID-19 Current Insights Into the Pathophysiology of Multisystem Inflammatory Syndrome in Children General pathology of Kawasaki disease. On the morphological alterations corresponding to the clinical manifestations Paediatric Inflammatory Multisystem Syndrome Temporally-Associated with SARS-CoV-2 Infection: An Overview Pulmonary and cardiac pathology in African American patients with COVID-19: an autopsy series from New Orleans Multisystem inflammatory syndrome in children is driven by zonulin-dependent loss of gut mucosal barrier Deep immune profiling of MIS-C demonstrates marked but transient immune activation compared to adult and pediatric COVID-19 HLA class I-associated expansion of TRBV11-2 T cells in multisystem inflammatory syndrome in children We thank the parents, who provided consent to include their child in medical literature. We also thank Dr Santiago Melón and Dr Marta Elena Argüelles for their help in interpreting viral findings.