Sex: M
Vaccine: COVID19, FLUX, RSV
Symptoms: Myopericarditis, Physical examination, Serum ferritin
Clinical narrative: HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS (HLH)-ASSOCIATED MYOPERICARDITIS; HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS (HLH)-ASSOCIATED MYOPERICARDITIS; This is a literature report for the following literature source(s):  A 63-year-old male patient received rsv vaccine prot.subunit pref 2v (RSV VACCINE PROT.SUBUNIT PREF 2V), as dose number unknown, single (Batch/Lot number: unknown) for immunisation; COVID-19 vaccine (COVID-19 VACCINE), as dose number unknown, single) for covid-19 immunisation; influenza vaccine (INFLUENZA VACCINE), as dose number unknown, single) for influenza immunisation. The patient's relevant medical history and concomitant medications were not reported. The following information was reported: HAEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS (medically significant, life threatening) and MYOPERICARDITIS (medically significant, life threatening), 1 week after the suspect product(s) administration, outcome "recovering", described as "HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS (HLH)-ASSOCIATED MYOPERICARDITIS". The patient underwent the following laboratory tests and procedures: Echocardiogram: a moderate circumferential pericardial effusion, notes: without evidence of tamponade; Haematology test: derangements included severe thrombocytopenia and, notes: a grossly elevated ferritin of over 77000. This constellation of findings in the setting of recent vaccination prompted the concern for HLH; IL-2 receptor assay: returned grossly elevated; continued to downtrend, notes: improvement in the pericardial effusion without drainage; organ functions: improvement; physiologic: improvement; Serum ferritin: Over 77000, notes: grossly elevated. Therapeutic measures were taken as a result of haemophagocytic lymphohistiocytosis.  Clinical course:CASE PRESENTATION: 63-year-old gentleman developing increased weakness and myalgias 1 week post influenza, COVID, and RSV vaccination simultaneously. He was found to be in shock with significant metabolic acidosis and new onset A-fib with RVR. An echocardiogram was obtained which showed a moderate circumferential pericardial effusion without evidence of tamponade. He was found to have multi-system organ involvement with an AKI, worsening respiratory failure, and non-cholestatic transaminitis requiring vasopressor initiation and intubation ultimately for worsening hypoxemic respiratory failure. Hematologic derangements included severe thrombocytopenia and a grossly elevated ferritin of over 77,000. This constellation of findings in the setting of recent vaccination prompted the concern for HLH; definitive IL-2 receptor assay was ordered which returned grossly elevated. The patient demonstrated response to aggressive resuscitation and a systemic steroid course with improvement including physiologic parameters and organ functions. Il-2 receptor values continued to downtrend and improvement in the pericardial effusion without drainage. DISCUSSION: HLH is an important clinical entity to be considered in critically ill patients. COVID-19 infection or vaccination, and to a lesser extent, RSV and influenza vaccinations have been linked with HLH, while COVID-19 associated myopericarditis has been described to some extent, the concomitance of these sequelae have not yet been described in literature. The patient's robust response to steroids in the setting of pathognomic biochemical markers serves as strong evidential support for the diagnosis of HLH as does the resolution of the pericardial effusion after pharmacologic intervention. While the pathophysiologic mechanisms remain unclear, excessive lymphocyte proliferation especially CD cytotoxic lymphocytes, known to play an important role in HLH. CONCLUSIONS: HLH is a rare but life-threatening immune activation state that has been reported following COVID and influenza vaccinations. Myopericarditis is also a very rare, but described phenomenon following COVID vaccination. To the best of the authors' knowledge, this is the first case in an adult describing HLH and myopericarditis following simultaneous COVID, influenza, and RSV vaccinations. Clinicians should consider these disease entities early in undertaking meaningful diagnostic workup and implementing management strategies early to yield favorable outcomes.; Sender's Comments: As there is limited information in the case provided, the causal association between the events haemophagocytic lymphohistiocytosis, and myopericarditis and the suspect drug RSV VACCINE PROT.SUBUNIT PREF 2V cannot be excluded. The case will be reassessed once new information is available.  The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to Regulatory Authorities, Ethics Committees, and Investigators, as appropriate.