[The neurology of COVID-19]. / La neurología de COVID-19.

The clinical manifestations of COVID-19 are reminiscent of those of acute respiratory distress syndrome induced by cytokine release syndrome and secondary hemophagocytic lymphohistiocytosis that is observed in patients with other coronaviruses such as SARS-CoV and MERS-CoV. Neurologists face the challenge of assessing patients with pre-existing neurological diseases who have contracted SARS-CoV-2, patients with COVID-19 who present neurological emergencies, and patients who are carriers of the virus and have developed secondary neurological complications, either during the course of the disease or after it. Some authors and recent literature reports suggest that the presence of neurological manifestations in patients who are carriers of SARS-CoV-2 may be associated with a greater severity of the disease.

Las manifestaciones clínicas de COVID-19 recuerdan las del síndrome de insuficiencia respiratoria aguda inducido por el síndrome de liberación de citocinas y la linfohistiocitosis hemofagocitica observada en pacientes con otros coronavirus como SARS-CoV y MERS-CoV. Los neurólogos tienen el reto de evaluar pacientes con enfermedades neurológicas preexistentes que contraen SARS-CoV-2, pacientes con COVID-19 que presentan emergencias neurológicas y pacientes portadores del virus que desarrollan complicaciones neurológicas secundarias, durante el curso de la enfermedad o posterior a la misma. Algunos autores y reportes en la literatura recientes sugieren que las manifestaciones neurológicas en pacientes portadores de SARS-CoV-2 pueden asociarse con mayor gravedad de la enfermedad.

Haemophagocytic lymphohistiocytosis following a COVID-19 infection: case report.

The case of a 57-year-old male patient with jaundice, high-grade fever, and upper abdominal pain who was recovering from a mild coronavirus disease-19 (COVID-19) infection is reported. Laboratory analysis showed liver injury with high levels of AST and ALT, as well as an elevated serum ferritin level. The patient underwent a bone marrow biopsy which showed features of hemophagocytic lymphohistiocytosis (HLH), a systemic syndrome caused by immune activation. The patient was successfully treated with etoposide and dexamethasone and kept on maintenance therapy with cyclosporine, with resolution of the HLH. The discussion highlights that COVID-19 infection may cause liver injury, and in severe cases, patients may develop HLH as a cause for liver injury. The incidence of HLH in adults with severe COVID-19 infection is estimated to be lower than 5%. The association between HLH and COVID-19 infection has been studied due to immunological hyperactivation. Signs such as persistent high fever, hepatosplenomegaly, and progressive pancytopenia should raise suspicion for the diagnosis of overlapping HLH. A specific approach using steroids and etoposide, followed by maintenance therapy with cyclosporine, is proposed in the HLH-94 protocol as the mainstay of treatment. It is suggested that HLH should be suspected in patients with laboratory signs of liver injury following COVID-19 infection, especially in patients with high-grade fever and a history of rheumatic conditions.

Hypocomplementemic urticarial vasculitis case with hemophagocytic lymphohistiocytosis following SARS-CoV-2 mRNA vaccination.

A 61-year-old man with no previous record of autoimmune disease developed fever, polyarthralgia, purpura, and urticaria-like rash 2 weeks after the first dose of the Moderna mRNA-1273 vaccine, and symptoms deteriorated following the second dose. He presented reduced erythrocyte and platelet counts, hyperferritinemia, high sIL-2R levels, and severe hypocomplementemia. We diagnosed hypocomplementemic urticarial vasculitis (HUVS), and his symptoms as well as laboratory findings improved following treatment with mPSL 1000 mg/day for 3 days and PSL 40 mg/day. Twelve weeks following treatment initiation, the patient relapsed with fever, sore throat, pancytopenia, and hyperferritinemia when the PSL dose was reduced to 12.5 mg/day. Bone marrow biopsy and MRI presented fatty marrow and hemophagocytosis. The patient's blood cells started recovering using ATG + CsA + EPAG therapy for hemophagocytic lymphohistiocytosis (HLH). This is the first case report of HUVS and HLH following SARS-CoV-2 mRNA vaccination. It is presumed that SARS-CoV-2 mRNA vaccine can induce the excessive production of certain types of cytokines, such as TNF-α, IL-1, IL-4, IL-5, IL-6, and IL-17 as a consequence of IL-6 Amplification (IL-6 Amp). SARS-CoV-2 mRNA-vaccines can cause disruption of immune homeostasis in healthy individuals. An extremely rare disease of HUVS complicated by HLH can be developed as a consequence.

Common bone marrow signature in COVID-19-associated multisystem inflammatory syndrome in children: A first-wave small case series experience.

The hyper-inflammatory response, also known as multisystem inflammatory syndrome in children (MIS-C), represents a major concern in children with SARS-CoV-2 infection. We report bone marrow features of three patients with MIS-C who were diagnosed during the first wave of the SARS-CoV-2 pandemic. A bone marrow evaluation was performed at onset of the inflammatory condition in order to exclude secondary hemophagocytic lymphohistiocytosis (sHLH). The bone marrows of the patients presented common features: the erythroid and megakaryocytic lineages were prominently affected and hemophagocytosis was moderately increased, differently than observed in sHLH. Megakaryocytopoiesis was increased, representing a peculiar feature of MIS-C differing from sHLH. SARS-CoV-2 RT-PCR and viral panel were studied in bone marrow aspiration samples. MIS-C is a rare complication of SARS-CoV-2 infections in children. An immuno-dysregulation considering both innate and adaptive immunity together with vascular inflammation and endothelial dysfunction play a major role. Our observations, although limited due to the small sample size, suggest that there are unique features in the bone marrow of patients with MIS-C that are likely secondary to immuno-dysregulation, and there are notable differences in bone marrow features compared to those reported in sHLH.

Hemophagocytic lymphohistiocytosis diagnosed by bone marrow trephine biopsy in living post-COVID-19 patients: case report and mini-review.

Hemophagocytic lymphohistiocytosis (HLH) constitutes a life-threatening inflammatory syndrome. Postmortem histological findings of bone marrow (BM) from COVID-19 patients showed histiocytosis and hemophagocytosis and supported the hypothesis that secondary HLH (sHLH) may be triggered by SARS-CoV-2 infection. However, there are a limited number of sHLH cases in which trephine has been performed in living post-COVID-19 patients. Here we present a recent case and a mini-review of sHLH diagnosed by trephine biopsy in living patients after COVID-19. An 81-year-old man with a past medical history of hypertension, diabetes, ischemic stroke, was referred to the hospital to evaluate leukocytosis, pyuria, and elevation of inflammatory markers four weeks after recovering from COVID-19. Computed tomography of the abdomen did not reveal focal signs of infection or hepatosplenomegaly. The patient received intravenous meropenem and two packed red blood cell units. Leukocytes and C-reactive protein were gradually decreased. A BM biopsy was performed and the patient was discharged on cefixime. BM smear revealed severe anemia, lymphopenia, and dysplastic morphologic findings of erythroblasts, neutrophils, and megakaryocytes. Trephine biopsy revealed hypercellular marrow dyserythropoiesis, plasmacytosis, lymphocytosis, histiocytosis, hemophagocytosis, and the absence of granulomas or carcinoma. Immunohistochemistry documented a mixed population of T lymphocytes (CD3+) and B lymphocytes (CD20+). Strong positivity for CD68 confirmed histiocytosis. CD138 κ, λ staining proved polyclonal plasmacytosis. Perl's staining showed excess hemosiderin deposits. Based on our findings, we document sHLH in trephine BM biopsy of a living post-COVID-19 patient and persistent leukocytosis, underscoring the diagnostic value of trephine biopsy in preventing life-threatening conditions such as COVID-19.

Lamotrigine-associated haemophagocytic lymphohistiocytosis (HLH) confounded with underlying rheumatoid arthritis.

Haemophagocytic lymphohistiocytosis (HLH) is one of the rare haematological syndromes more commonly reported in infants/children than adults. This disease is known for its aggressive dysregulated immune response affecting the host rapidly, causing multiorgan dysfunction and thus carries a high mortality. The disease still remains cryptic in this current decade despite all the developments in the ever-evolving field of haematology. Due to its rare occurrence and being more frequent in infants and the paediatric population, the literature lacks enough data to standardise therapies. Such events in adults and the elderly are invariably related to an underlying insult such as infections, other autoimmune or rheumatological diseases or drugs. We describe an interesting case of a middle-aged Caucasian woman who presented with fever, pancytopenia and hepatitis, who was eventually diagnosed with HLH just in time to receive the life-saving specific treatment as per available guidelines.

Hemophagocytic lymphohistiocytosis after SARS-CoV-2 vaccination.

PURPOSE: The coronavirus disease 2019 (COVID-19) pandemic has led to the approval of novel vaccines with different mechanisms of action. Until now, more than 4.7 billion persons have been vaccinated around the world, and adverse effects not observed in pre-authorization trials are being reported at low frequency. METHODS: We report a case of severe hemophagocytic lymphohistiocytosis (HLH) after SARS-CoV-2 immunization and performed a literature search for all reported cases of COVID-19 vaccine-associated HLH. RESULTS: A 24-year-old female developed HLH after immunization with the mRNA COVID-19 vaccine Comirnaty. Diagnosis was made according to HLH-2004 criteria; the HScore was 259 (> 99% HLH probability) with maximum ferritin of 138.244 µg/L. The patient was initially treated with intravenous immunoglobulins (IVIGs) and dexamethasone without response. The addition of the human interleukin 1 receptor antagonist Anakinra resulted in full recovery within 6 weeks after vaccination. A literature search revealed 15 additional cases of HLH after SARS-CoV-2 vaccination, the majority after immunization with Comirnaty (n = 7) or the viral vector vaccine Vaxzevria (n = 6). Treatment modalities included corticosteroids (n = 13), Anakinra (n = 5), IVIGs (n = 5), and etoposide (n = 2). Eight patients underwent combination treatment. Three of 16 patients died. CONCLUSION: COVID-19 vaccines may occasionally trigger HLH, and Anakinra may be an efficacious treatment option for this condition.

Is COVID-19-associated cytokine storm distinct from non-COVID-19 secondary hemophagocytic lymphohistiocytosis?

Cytokine storm is an umbrella term that describes an inflammatory syndrome characterized by elevated levels of circulating cytokines and hyperactivation of innate and/or adaptive immune cells. One type of cytokine storm is hemophagocytic lymphohistiocytosis (HLH), which can be either primary or secondary. Severe COVID-19-associated pneumonia and acute respiratory distress syndrome (ARDS) can also lead to cytokine storm/cytokine release syndrome (CS/CRS) and, more rarely, meet criteria for the diagnosis of secondary HLH. Here, we review the immunobiology of primary and secondary HLH and examine whether COVID-19-associated CS/CRS can be discriminated from non-COVID-19 secondary HLH. Finally, we review differences in immunobiology between these different entities, which may inform both clinical diagnosis and treatment of patients.

A case of Hemophagocytic lymphohistiocytosis induced by COVID-19, and review of all cases reported in the literature.

Novel coronavirus infections 2019 (COVID-19) associated hyperinflammatory syndromes are well-defined clinical conditions and have a potential risk for severe infection. Hemophagocytic lymphohistiocytosis (HLH), a rare type of acute progressive hyperinflammatory syndrome, has been reported in a limited number of COVID-19 cases. In this article, we aimed to present a patient with HLH secondary to COVID-19 diagnosed by bone marrow biopsy, and to summarize and review HLH cases associated with COVID-19 in the literature. A 47-year-old male patient presented with complaints of fever, cough, abdominal discomfort, and nausea-vomiting. He had recovered from COVID-19 a month ago and was readmitted to the hospital due to the re-appearance of clinical symptoms after a two-week interval. The patient was diagnosed with HLH secondary to COVID-19 on sixth day of admission and fully recovered with systemic pulse steroid, intravenous immunoglobulin, and plasma exchange therapy. Analysis of literature searches revealed that 22 cases were definitely diagnosed with COVID-19-associated HLH, 16 of them were male. They had been treated with different anti-cytokine drugs, of which nine had died. The increasing number of HLH cases, which have high mortality rates, shows the importance of hyperinflammatory syndromes in COVID-19 patients. Some patients may experience hemophagocytosis in the late period of COVID-19, even while in recovery. Increased awareness and early treatment for HLH triggered by COVID-19 can be a life-saving effort for reducing mortality in severe COVID-19 cases.

Hemophagocytic syndrome secondary to SARS-Cov-2 infection: a case report.

BACKGROUND: Hemophagocytic syndrome (HPS) is a severe hyperinflammatory disease, whose diagnosis is based on the HLH-2004 criteria. In secondary forms of HLH (sHLH), the primary goal is treating the triggering factors such as COVID-19 (Coronavirus disease 2019). The link between the cytokine storm related to COVID-19 and development of sHLH has already been reported since the onset of pandemic, but little is known about clinical manifestations of HLH which develop after the patient's recovery from mild symptomatic or asymptomatic Sars-CoV-2 infection. CASE PRESENTATION: We describe the case of a woman diagnosed with sHLH related to previous Sars-CoV-2 infection and successfully treated with steroids, colchicine, etoposide and ruxolitinib. CONCLUSIONS: Our report suggests that HLH-like syndrome might be secondary to Sars-CoV-2 infection, even if the patient utterly recovered from the mildly symptomatic viral infection. In addition, we underline the treatment with low dose ruxolitinib plus etoposide as a potential choice for Sars-CoV-2 infection related HLH.

Hemophagocytic Lymphohistiocytosis Secondary to Peripheral T Cell Lymphoma with Rapid Onset and Fatal Progression in a Young Patient: A Case Report and Review of the Literature.

BACKGROUND Constant stimulation of lymphocytes and histiocytes can result in hemophagocytic lymphohistiocytosis (HLH), which can be primary or secondary (sHLH). The main causes of sHLH are infections and hematological malignancies, especially non-Hodgkin lymphoma. Despite new insights into the pathogenesis of HLH, the diagnosis and treatment of this immune disorder remain a great challenge. CASE REPORT We present a case of a young adult without comorbidities whose clinical course was nonspecific for several months and resulted in late diagnosis of HLH secondary to peripheral T cell lymphoma (PTCL). The etiological factor of recurring fever, hepatosplenomegaly, and deteriorating condition was unidentified for a long time before fatal sHLH was finally diagnosed. The patient was treated according to the HLH-2004 protocol; however, he did not achieve any response. Unfortunately, due to nonspecific symptoms, lack of lymphadenopathy for a long time, and negative positron emission tomography results, the diagnosis of PTCL was established only after the patient's death. CONCLUSIONS It should be emphasized that early diagnosis is crucial for better prognosis of patients with sHLH. Bone marrow biopsy is worth considering in patients with prolonged fever of unknown origin, hyperferritinemia, splenomegaly, and unexplained cytopenia of 2 or more lineages. Despite the existence of diagnostic and therapeutic protocols available in the literature, the prompt diagnosis and treatment of HLH remains a great challenge. More precise and specific diagnostic tools for HLH are needed.

Cytokine Storms in the Course of COVID-19 and Haemophagocytic Lymphohistiocytosis in Pregnant and Postpartum Women.

The term 'cytokine storm' (CS) applies to a pathological autoimmune reaction when the interactions that lead to cytokine production are destabilised and may even lead to death. CS may be induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In this study, we present our analysis of certain pathological processes that induce a CS in pregnant and postpartum women. We draw our attention to the similarities between the severe course of Coronavirus Disease 2019 (COVID-19) and haemophagocytic lymphohistiocytosis (HLH). It is noteworthy that many of the criteria used to diagnose HLH are described as COVID-19 mortality predictors. Cytokine storms are considered to be an important cause of death in patients with the severe course of SARS-CoV-2 infection. Due to the fact that pregnant women are in an immunosuppressive state, viral pulmonary infections are more perilous for them-possible risks include miscarriage, intrauterine growth restriction or birth before the term; sometimes ventilation support is needed. HLH should be considered in pregnant and puerperal women suffering from moderately severe to severe COVID-19 and presenting with: fever unresponsive to antibiotic therapy, cytopenia, hepatitis and hyperferritinaemia. The HLH disorder is rare and difficult to diagnose; however, its early detection could reduce patient mortality.

Risk factors for secondary hemophagocytic lymphohistiocytosis in severe coronavirus disease 2019 adult patients.

BACKGROUND: Secondary hemophagocytic lymphohistiocytosis (sHLH) is a life-threatening hyperinflammatory event and a fatal complication of viral infections. Whether sHLH may also be observed in patients with a cytokine storm induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is still uncertain. We aimed to determine the incidence of sHLH in severe COVID-19 patients and evaluate the underlying risk factors. METHOD: Four hundred fifteen severe COVID-19 adult patients were retrospectively assessed for hemophagocytosis score (HScore). A subset of 7 patients were unable to be conclusively scored due to insufficient patient data. RESULTS: In 408 patients, 41 (10.04%) had an HScore ≥169 and were characterized as "suspected sHLH positive". Compared with patients below a HScore threshold of 98, the suspected sHLH positive group had higher D-dimer, total bilirubin, alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, serum creatinine, triglycerides, ferritin, interleukin-6, C-reactive protein, procalcitonin, lactate dehydrogenase, creatine kinase isoenzyme, troponin, Sequential Organ Failure Assessment (SOFA) score, while leukocyte, hemoglobin, platelets, lymphocyte, fibrinogen, pre-albumin, albumin levels were significantly lower (all P < 0.05). Multivariable logistic regression revealed that high ferritin (>1922.58 ng/mL), low platelets (<101 × 109/L) and high triglycerides (>2.28 mmol/L) were independent risk factors for suspected sHLH in COVID-19 patients. Importantly, COVID-19 patients that were suspected sHLH positive had significantly more multi-organ failure. Additionally, a high HScore (>98) was an independent predictor for mortality in COVID-19. CONCLUSIONS: HScore should be measured as a prognostic biomarker in COVID-19 patients. In particular, it is important that HScore is assessed in patients with high ferritin, triglycerides and low platelets to improve the detection of suspected sHLH.