Could hemophagocytic lymphohistiocytosis be the core issue of severe COVID-19 cases?

An antibody to IL-1 receptor 7 protects mice from LPS-induced tissue and systemic inflammation

Introduction

Interleukin-18 (IL-18), a pro-inflammatory cytokine belonging to the IL-1 Family, is a key mediator ofautoinflammatory diseases associated with the development of macrophage activation syndrome (MAS).High levels of IL-18 correlate with MAS and COVID-19 severity and mortality, particularly in COVID-19patients with MAS. As an inflammation inducer, IL-18 binds its receptor IL-1 Receptor 5 (IL-1R5), leadingto the recruitment of the co-receptor, IL-1 Receptor 7 (IL-1R7). This heterotrimeric complex subsequentlyinitiates downstream signaling, resulting in local and systemic inflammation.

Methods

We reported earlier the development of a novel humanized monoclonal anti-human IL-1R7 antibody whichspecifically blocks the activity of human IL-18 and its inflammatory signaling in human cell and wholeblood cultures. In the current study, we further explored the strategy of blocking IL-1R7 inhyperinflammation in vivo using animal models.

Results

We first identified an anti-mouse IL-1R7 antibody that significantly suppressed mouse IL-18 andlipopolysaccharide (LPS)-induced IFNg production in mouse splenocyte and peritoneal cell cultures. Whenapplied in vivo, the antibody reduced Propionibacterium acnes and LPS-induced liver injury and protectedmice from tissue and systemic hyperinflammation. Importantly, anti-IL-1R7 significantly inhibited plasma,liver cell and spleen cell IFNg production. Also, anti-IL-1R7 downregulated plasma TNFa, IL-6, IL-1b,MIP-2 production and the production of the liver enzyme ALT. In parallel, anti-IL-1R7 suppressed LPSinducedinflammatory cell infiltration in lungs and inhibited the subsequent IFNg production andinflammation in mice when assessed using an acute lung injury model.

Discussion

Altogether, our data suggest that blocking IL-1R7 represents a potential therapeutic strategy to specificallymodulate IL-18-mediated hyperinflammation, warranting further investigation of its clinical application intreating IL-18-mediated diseases, including MAS and COVID-19.

Haemophagocytic lymphohistiocytosis post-ChAdOx1 nCoV-19 vaccine: A rare case

The severe acute respiratory syndrome coronavirus 2 pandemic started in December 2019, spread like wildfire and took an immense toll on human life. ChAdOx1 nCoV-19 vaccine was used worldwide for the prevention of Covid-19. Covid-19 has been implicated in the causation of severe haemophagocytic lymphohistiocytosis (HLH) syndrome. However, the same has not been reported with ChAdOx1 nCoV-19 vaccine in the literature. We report a young man who developed secondary HLH post-ChAdOx1 nCoV-19 vaccination.

Kinetics of IL-6, C-reactive Protein and Fibrinogen Levels in COVID-19 Outpatients Who Evolved to Hypoxemia

Introduction

Despite the efficacy of the COVID-19, the search for improvements in the management of severe/critical cases continues to be important. The aim is to demonstrate the kinetics of 4 serological markers in patients with COVID-19 who evolved in hypoxemia.

Methods

From June to December 2020, the Health Secretariat of Rondônia State, Brazil, established a home medical care service team (HMCS) that provided clinical follow-up for health professionals and military personnel with COVID-19. The clinical and laboratory monitoring was individualized at home by a nursing and medical team. In addition to laboratory parameters, C-reactive protein (CRP), interleukin-6 (IL-6), fibrinogen, and D-dimer levels were periodically taken to monitor the evolution of treatment.

Results

Of 218 patients telemonitored, 48 patients needed special care by the HMCS team due to shortness of breath. Chest tomography showed multiple ground-glass shadows and lung parenchymal condensations that was compatible with secondary bacterial infection associated with leukocytosis, for which antibiotics were prescribed. The symptoms were accompanied by increases of CRP and IL-6 levels followed by fibrinogen after a few days, for which an anticoagulant therapy was included. Thirty-three patients evolved to improvements in clinical signs and laboratory results. Between the sixth and eighth day of illness, 15 patients presented signs of hypoxemia with low O2 saturation accompanied with an increase in the respiratory rate, with some of them requiring oxygen therapy. As they did not present signs of clinical severity, but their laboratory markers showed an abrupt IL-6 peak that was higher than the increase in CRP and a new alteration in fibrinogen levels, they received a supplemental dose of anticoagulant and a high dose of corticosteroids, which resulted in clinical improvement.

Conclusion

Our study demonstrates that monitoring of IL-6 and CRP may identify precocious hypoxemia in COVID-19 patients and prevented the progressive deterioration of the lung injury.

Bone marrow haematopoiesis in patients with COVID-19

AIMS

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection broadly affects organ homeostasis, including the haematopoietic system. Autopsy studies are a crucial tool for investigation of organ-specific pathologies. Here we perform an in-depth analysis of the impact of severe coronavirus disease 2019 (COVID-19) on bone marrow haematopoiesis in correlation with clinical and laboratory parameters.

METHODS AND RESULTS

Twenty-eight autopsy cases and five controls from two academic centres were included in the study. We performed a comprehensive analysis of bone marrow pathology and microenvironment features with clinical and laboratory parameters and assessed SARS-CoV-2 infection of the bone marrow by quantitative polymerase chain reaction (qPCR) analysis. In COVID-19 patients, bone marrow specimens showed a left-shifted myelopoiesis (19 of 28, 64%), increased myeloid-erythroid ratio (eight of 28, 28%), increased megakaryopoiesis (six of 28, 21%) and lymphocytosis (four of 28, 14%). Strikingly, a high proportion of COVID-19 specimens showed erythrophagocytosis (15 of 28, 54%) and the presence of siderophages (11 of 15, 73%) compared to control cases (none of five, 0%). Clinically, erythrophagocytosis correlated with lower haemoglobin levels and was more frequently observed in patients from the second wave. Analysis of the immune environment showed a strong increase in CD68+ macrophages (16 of 28, 57%) and a borderline lymphocytosis (five of 28, 18%). The stromal microenvironment showed oedema (two of 28, 7%) and severe capillary congestion (one of 28, 4%) in isolated cases. No stromal fibrosis or microvascular thrombosis was found. While all cases had confirmed positive testing of SARS-CoV-2 in the respiratory system, SARS-CoV-2 was not detected in the bone marrow by high-sensitivity PCR, suggesting that SARS-CoV-2 does not commonly replicate in the haematopoietic microenvironment.

CONCLUSIONS

SARS-CoV-2 infection indirectly impacts the haematological compartment and the bone marrow immune environment. Erythrophagocytosis is frequent and associated with lower haemoglobin levels in patients with severe COVID-19.

An analysis of reported cases of hemophagocytic lymphohistiocytosis (HLH) after COVID-19 vaccination

Although COVID-19 vaccines are an effective public health tool to combat the global pandemic, serious adverse events, such as hemophagocytic lymphohistiocytosis (HLH), caused by them are a concern. In this systematic review, cases of HLH reported after COVID-19 vaccination have been examined to understand the relationship between the two and propose effective therapeutic strategies. Furthermore, ruxolitinib's potential as a cytokine inhibitor and its affinity for CD25 were initially assessed through molecular docking, aiming to aid targeted HLH therapy. PubMed and Web of Science databases were searched for published individual case reports on the occurrence of HLH after the administration of any COVID-19 vaccine. A total of 17 articles (25 patients) were included in this qualitative analysis. Furthermore, molecular docking was employed to investigate the therapeutic potential of ruxolitinib for HLH after COVID-19 vaccination. The mean age of patients who developed HLH after COVID-19 vaccination was 48.1 years. Most HLH episodes occurred after the BNT162b2 mRNA COVID-19 vaccination (14/25 cases) and to an extent after the ChAdOx1 nCov-19 vaccination (5/25 cases). Almost all affected patients received steroid and antibiotic therapy. Three patients died despite treatment because of esophagus rupture, neutropenic fever, bacteroides bacteremia, refractory shock, and encephalopathy and shock. Visual docking results of IL-2 Rα and ruxolitinib using the Discovery Studio 2019 Client software yielded a model score of 119.879. The findings highlight the importance of considering and identifying the adverse effects of vaccination and the possibility of using ruxolitinib for treating HLH after COVID-19 vaccination.

Bone marrow alterations in COVID-19 infection: The root of hematological problems

INTRODUCTION

The 2019 coronavirus disease (COVID-19) is a respiratory infection caused by the SARS-CoV-2 virus with a significant impact on the hematopoietic system and homeostasis. The effect of the virus on blood cells indicates the involvement of the bone marrow (BM) as the place of production and maturation of these cells by the virus and it reminds the necessity of investigating the effect of the virus on the bone marrow.

METHOD

To investigate the effects of COVID-19 infection in BM, we reviewed literature from the Google Scholar search engine and PubMed database up to 2022 using the terms "COVID-19; SARS-CoV-2; Bone marrow; Thrombocytopenia; Hemophagocytosis; Pancytopenia and Thrombocytopenia.

RESULTS

Infection with the SARS-CoV-2 virus is accompanied by alterations such as single-line cytopenia, pancytopenia, hemophagocytosis, and BM necrosis. The presence of factors such as cytokine release syndrome, the direct effect of the virus on cells through different receptors, and the side effects of current treatments such as corticosteroids are some of the important mechanisms in the occurrence of these alterations.

CONCLUSION

To our knowledge, this review is the first study to comprehensively investigate BM alterations caused by SAR-CoV-2 virus infection. The available findings show that the significant impact of this viral infection on blood cells and the clinical consequences resulting from them are deeper than previously thought and it may be rooted in the changes that the virus causes in the BM of patients.

A prospective, single-center, randomized phase 2 trial of etoposide in severe COVID-19

The systemic inflammatory response seen in patients with severe COVID-19 shares many similarities with the changes observed in hemophagocytic lymphohistiocytosis (HLH); a disease characterized by excessive immune activation. Many patients with severe COVID qualify for a diagnosis of HLH. Etoposide, an inhibitor of topoisomerase II is used to control inflammation in HLH. This randomized, open-label, single center phase II trial attempted to determine whether etoposide can be used to blunt the inflammatory response in severe COVID. This trial was closed early after eight patients were randomized. This underpowered trial did not meet its primary endpoint of improvement in pulmonary status by two categories on an 8 point ordinal scale of respiratory function. There were not significant differences in secondary outcomes including overall survival at 30 days, cumulative incidence of grade 2 through 4 adverse events during hospitalization, duration of hospitalization, duration of ventilation and improvement in oxygenation or paO2/FIO2 ratio or improvement in inflammatory markers associated with cytokine storm. A high rate of grade 3 myelosuppression was noted in this critically ill population despite dose reduction, a toxicity which will limit future attempts to explore the utility of etoposide for virally-driven cytokine storm or HLH.

Hemophagocytic Syndrome and COVID-19: A Comprehensive Review

Hemophagocytic lymphohistiocytosis (HLH), a hyperinflammatory hyperferritinemic syndrome, is triggered by various etiologies and diseases and can lead to multiorgan dysfunction and death. There are two types of HLH: primary and secondary. Primary HLH (pHLH) is caused by a genetic mutation resulting in dysfunction in cytotoxic T lymphocytes (CTLs), natural killer (NK) cells, hyperactivated immune cells, and hypercytokinemia. In secondary HLH (sHLH), an underlying etiology is the cause of the disease. Infections, malignancy, and autoimmune diseases are well-known triggers for sHLH. Infectious triggers for sHLH are most frequently viruses, where different mechanisms, including dysregulated CTLs and NK cell activity and persistent immune system stimulation, have been reported. Similarly, in severe coronavirus disease 2019 (COVID-19) patients, a hyperinflammatory mechanism leading to hypercytokinemia and hyperferritinemia has been demonstrated. A similar dysfunction in CTLs and NK cells, persistent immune system stimulation with increased cytokines production, and severe end-organ damage have been reported. Therefore, a significant overlap is present between the clinical and laboratory features seen in COVID-19 and sHLH. However, SARS-CoV-2, similar to other viruses, can trigger sHLH. Hence, a diagnostic approach is needed in severe COVID-19 patients presenting with multiorgan failure, in whom sHLH should be considered.

Elevated free interleukin-18 associated with severity and mortality in prospective cohort study of 206 hospitalised COVID-19 patients

BACKGROUND

Divergence between deterioration to life-threatening COVID-19 or clinical improvement occurs for most within the first 14 days of symptoms. Life-threatening COVID-19 shares clinical similarities with Macrophage Activation Syndrome, which can be driven by elevated Free Interleukin-18 (IL-18) due to failure of negative-feedback release of IL-18 binding protein (IL-18bp). We, therefore, designed a prospective, longitudinal cohort study to examine IL-18 negative-feedback control in relation to COVID-19 severity and mortality from symptom day 15 onwards.

METHODS

662 blood samples, matched to time from symptom onset, from 206 COVID-19 patients were analysed by enzyme-linked immunosorbent assay for IL-18 and IL-18bp, enabling calculation of free IL-18 (fIL-18) using the updated dissociation constant (K_d) of 0.05 nmol. Adjusted multivariate regression analysis was used to assess the relationship between highest fIL-18 and outcome measures of COVID-19 severity and mortality. Re-calculated fIL-18 values from a previously studied healthy cohort are also presented.

RESULTS

Range of fIL-18 in COVID-19 cohort was 10.05-1157.7 pg/ml. Up to symptom day 14, mean fIL-18 levels increased in all patients. Levels in survivors declined thereafter, but remained elevated in non-survivors. Adjusted regression analysis from symptom day 15 onwards showed a 100 mmHg decrease in PaO₂/FiO₂ (primary outcome) for each 37.7 pg/ml increase in highest fIL-18 (p < 0.03). Per 50 pg/ml increase in highest fIL-18, adjusted logistic regression gave an odds-ratio (OR) for crude 60-day mortality of 1.41 (1.1-2.0) (p < 0.03), and an OR for death with hypoxaemic respiratory failure of 1.90 [1.3-3.1] (p < 0.01). Highest fIL-18 was associated also with organ failure in patients with hypoxaemic respiratory failure, with an increase of 63.67 pg/ml for every additional organ supported (p < 0.01).

CONCLUSIONS

Elevated free IL-18 levels from symptom day 15 onwards are associated with COVID-19 severity and mortality. ISRCTN: #13450549; registration date: 30/12/2020.

Case report: A rare case of Rosai-Dorfman-Destombes disease after the COVID-19 infection

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is known to cause immune dysregulation and, therefore, has varied and often rare presentations. Rosai-Dorfman-Destombes disease (RDD) is an unusual non-Langerhans cell (non-LC) histiocytosis presenting with massive lymphadenopathy and various systemic symptoms. A 55-year-old Asian-American woman with no significant medical history or recent use of new drugs initially presented with cervical lymphadenopathy and urticarial rash 1 week after receiving the COVID-19 messenger RNA (mRNA) vaccine (Moderna, mRNA-1273) against SARS-CoV-2. The biopsy of the skin rash was consistent with a drug reaction. Approximately 2 months later, she developed mild flu-like symptoms and was diagnosed with a COVID-19 infection. Her symptoms were mild and self-resolving. Approximately 3 months later, she developed a generalized patchy erythematous rash on the face and the body that gradually worsened; diffuse lymphadenopathy involving the bilateral cervical, axillary, and inguinal areas; and constitutional symptoms. Laboratory results were consistent with lymphopenia, anemia, and an elevated sedimentation rate. Supraclavicular lymph node biopsy showed Rosai-Dorfman disease with a marked polyclonal plasmacytosis. She was started on a tapering dose of corticosteroids and showed clinical improvements over the next few weeks. Herein, we present a rare case of a histiocytic disorder that developed after contracting the SARS-COV2 infection in the event of receiving a recent mRNA COVID vaccination.

Efficacy and safety profile of corticosteroids and non-steroidal anti-inflammatory drugs in COVID-19 management: A narrative review

Due to the fact that coronavirus disease 2019 (COVID-19) is still prevalent, and current reports show that some parts of the world have seen increase in incidence, it is relevant that health professionals and scientists know about recent or novel trends, especially drug treatments. Additionally, the safety profiles of these drug treatments need to be documented and shared with the public. Some studies have demonstrated the clinical benefits of non-steroidal anti-inflammatory drugs (NSAIDs) and corticosteroids in COVID-19 treatment. On the contrary, others have also reported that NSAIDs and corticosteroids may worsen symptoms associated with COVID-19. While some researchers have suggested that corticosteroids may be helpful if used in the early stages of COVID-19, there are still some conflicting findings regarding the use of corticosteroids in certain viral infections. Our review suggests that methylprednisolone, dexamethasone, and ibuprofen have therapeutic potential in reducing mortality due to COVID-19 among hospitalized patients. This review also highlights the fact that the use of NSAIDs is not associated with adverse outcomes of COVID-19. In reality, evidence suggests that NSAIDs do not increase the risk of COVID-19 infections. Also, the literature reviewed suggests that corticosteroid treatment in COVID-19 was linked with a decrease in all-cause mortality and disease progression, without increase in adverse events when compared to no corticosteroid treatment.

Are Antisense Long Non-Coding RNA Related to COVID-19?

Fighting external pathogens relies on the tight regulation of the gene expression of the immune system. Ferroptosis, which is a distinct form of programmed cell death driven by iron, is involved in the enhancement of follicular helper T cell function during infection. The regulation of RNA is a key step in final gene expression. The present study aimed to identify the expression level of antisense lncRNAs (A2M-AS1, DBH-AS1, FLVCR1-DT, and NCBP2AS2-1) and FLVCR1 in COVID-19 patients and its relation to the severity of the disease. COVID-19 patients as well as age and gender-matched healthy controls were enrolled in this study. The expression level of the antisense lncRNAs was measured by RT-PCR. Results revealed the decreased expression of A2M-AS1 and FLVCR1 in COVID-19 patients. Additionally, they showed the increased expression of DBH-AS1, FLVCR1-DT, and NCBP2AS2. Both FLVCR1-DT and NCBP2AS2 showed a positive correlation with interleukin-6 (IL-6). DBH-AS1 and FLVCR1-DT had a significant association with mortality, complications, and mechanical ventilation. A significant negative correlation was found between A2M-AS1 and NCBP2AS2-1 and between FLVCR1 and FLVCR1-DT. The study confirmed that the expression level of the antisense lncRNAs was deregulated in COVID-19 patients and correlated with the severity of COVID-19, and that it may have possible roles in the pathogenesis of this disease.

Utility of the HScore for Predicting COVID-19 Severity

BACKGROUND

Cytokine release syndrome is a life-threatening condition known to cause fever and multiple organ dysfunction and is suspected to be related to the severity of coronavirus disease 2019 (COVID-19). We sought to examine the utility of the HScore and non-cytokine markers of inflammation for predicting COVID-19 outcomes. We hypothesized that cytokine storm, assessed by a modified HScore, would be linked to more severe COVID-19 symptoms and higher mortality.

METHODS

 A retrospective review of records from a large, private hospital system was conducted on patients with hemophagocytic lymphohistiocytosis (HLH) (2014-2019) and compared to a large cohort of COVID-19-positive patients (2020). Patients with a sufficient number of elements in their record for a modified HScore calculation (n=4663), were further subdivided into population 1 (POP1, n=67; HLH, n=493 COVID-19), which had eight HScore elements, and population 2 (POP2) with six available HScore elements (POP2, n=102; HLH, n=4561 COVID-19).

RESULTS

Modified HScore predicted COVID-19 severity in POP1 and POP2 as measured by higher odds of being on a ventilator (POP2 OR: 1.46, CI: 1.42-1.5), ICU admission (POP2 OR: 1.38, CI: 1.34-1.42), a longer length of stay (p<0.0001), and higher mortality (POP2 OR: 1.34, CI: 1.31-1.39). C-reactive protein (CRP) and white blood cell (WBC) count were the most consistent non-cytokine predictors of COVID-19 severity.

CONCLUSION

 Cytokine storm, evaluated using a modified HScore, appeared to play a role in the severity of COVID-19 infection, and selected non-cytokine markers of inflammation were predictive of disease severity.

Virtual autopsy in SARS-CoV-2 breakthrough infection: a case report

It is well documented that COVID-19 vaccines are effective tools for limiting the pandemic. Unfortunately, as is true for all vaccines, SARS-CoV-2 infection in vaccinated individuals is still possible.

We present an autopsy case of SARS-CoV-2 infection after vaccination (“breakthrough infection”) in an elderly man with several comorbidities where post-mortem CT scan was performed. The death was histologically attributed to cardio-respiratory arrest due to ischemic heart failure related to superinfected COVID-19 pneumonia and pre-existing comorbidities. For the first time in the literature, PMCT imaging related to a fatal, autopsy case of breakthrough SARS-CoV-2 infection is reported. PMCT of the lungs, in accordance with histopathological results, showed few signs of COVID-19 pneumonia, large area of consolidation in the right lower lobe, interpreted as bronco-pneumonic focus, and hypostasis.

These findings were well-correlated with the previously reported literature about both PMCT and clinical CT imaging of the lungs in non-vaccinated individuals with early COVID-19 pneumonia and about pulmonary clinical CT imaging in COVID-19 pneumonia in breakthrough SARS-COV-2 infections.

Further studies are needed to cover the whole spectrum of PMCT lung imaging in fatal breakthrough SARS-CoV-2 infection, however, this case represent a first step for exploring this difficult challenge during SARS-CoV-2 pandemic using virtual autopsy.

An Unusual Case of Secondary Hemophagocytic Lymphohistiocytosis in a Patient Diagnosed With Triple Infection: COVID-19, HIV, and Histoplasmosis

In this study, we present a unique instance of a patient who developed hemophagocytic lymphohistiocytosis secondary to a triple infection with coronavirus disease 2019 (COVID-19), HIV, and histoplasmosis. We emphasize the proinflammatory dysregulations driving the severity of COVID-19 infection in this setting and highlight the importance of early diagnosis and targeted therapy of underlying conditions as a method to increase the chance of survival.

Effective Natural Killer Cell Degranulation Is an Essential Key in COVID-19 Evolution

NK degranulation plays an important role in the cytotoxic activity of innate immunity in the clearance of intracellular infections and is an important factor in the outcome of the disease. This work has studied NK degranulation and innate immunological profiles and functionalities in COVID-19 patients and its association with the severity of the disease. A prospective observational study with 99 COVID-19 patients was conducted. Patients were grouped according to hospital requirements and severity. Innate immune cell subpopulations and functionalities were analyzed. The profile and functionality of innate immune cells differ between healthy controls and severe patients; CD56dim NK cells increased and MAIT cells and NK degranulation rates decreased in the COVID-19 subjects. Higher degranulation rates were observed in the non-severe patients and in the healthy controls compared to the severe patients. Benign forms of the disease had a higher granzymeA/granzymeB ratio than complex forms. In a multivariate analysis, the degranulation capacity resulted in a protective factor against severe forms of the disease (OR: 0.86), whereas the permanent expression of NKG2D in NKT cells was an independent risk factor (OR: 3.81; AUC: 0.84). In conclusion, a prompt and efficient degranulation functionality in the early stages of infection could be used as a tool to identify patients who will have a better evolution.

Hemophagocytic lymphohistiocytosis: An unusual presentation of disseminated tuberculosis: A case report and literature review

Background

Hemophagocytic lymphohistiocytosis (HLH) is an aggressive and life-threatening syndrome associated with cytokine storm. Here, we present a patient with acquired HLH associated with Mycobacterial tuberculosis infection.

Case presentation

We report a 66-year-old hypertensive and diabetic male patient who presented with four days history of fever and abdominal pain. Denied history of cough and weight loss. Laboratory investigation showed: elevated ferritin, C-reactive protein, and triglyceride. Bone marrow examination showed > 50% hemophagocytosis (RBCs and platelets ingested by macrophages), positive acid-fast bacillus for Mycobacterium tuberculosis bacilli, and no evidence of malignancy. Complete blood count showed anemia and thrombocytopenia. The patient fulfilled six out of eight clinical criterions of the acquired Hemophagocytic lymphohistiocytosis (HLH). The patient was managed with anti-tuberculous medications with adjuvant steroid. On the subsequent days, the patient showed significant clinical improvement and discharged home. However, the patient passed away a week after home discharge.

Conclusion

The present case highlights on the importance of early diagnosis and treatment of acquired HLH associated with tuberculous infection to improve the clinical outcome of the patient.

Management of presumed candida endophthalmitis during the COVID-19 pandemic: Case report and review of the literature

Purpose

To report the management of a case of candida endophthalmitis following intubation for SARS-CoV-2 ARDS, during the first lockdown, underlining consequently the limited access to the gold standard of care.

Methods

Case report.

Results

We have described the case of a 56-year-old Hispanic man who developed bilateral Candida endophthalmitis after one month of hospitalization in the intensive care unit for severe SARS-CoV-2 pneumonia. Multimodal imaging was obtained. Full serological screening for infection was done resulting negative. A diagnostic vitrectomy was impossible due to the limited access at the surgery room. Diagnosis of presumed candida endophthalmitis was made, according to a highly qualified center, and therapy with intravenous liposomal amphotericin B was administered. At three months, we observed lack of vitreous opacities and atrophic scars with no active lesions.

Conclusions

Diagnosis of candida endophthalmitis was a challenge in this pandemic scenario, given the impossibility of performing a diagnostic vitrectomy. Therefore, it was mainly based on patient's clinical manifestations, multimodal imaging and on unanimity of collegiality between our hospital and the highly specialized center.

Outcome of Viral-associated Hemophagocytic Lymphohistiocytosis at a Tertiary Hospital

BACKGROUND

Little is known about viral-associated hemophagocytic lymphohistiocytosis (HLH) in Oman. This study was done to assess the epidemiology, clinical features and outcome of viral-associated HLH in our setting.

METHODS

We retrospectively reviewed children (0-18 years) managed for viral-associated HLH at the Sultan Qaboos University Hospital, Oman, over a 15-year period (2006-2020). Patients' medical records were used to describe their demographic, clinical and laboratory features, management and outcome.

RESULTS

Fifty-six children were managed for HLH at Sultan Qaboos University Hospital over the last 15 years (2006-2020) of whom a third (19; 34%) had a viral trigger. The median age at the time of diagnosis of viral-associated HLH was 83 (13-96) months. Fever, cytopenia, hyperferritinemia and evidence of hemophagocytosis in bone marrow were the most consistent findings. Most of these children had either genetic predisposition to HLH (8/19; 42%) or underlying immunodeficiency secondary to malignant conditions or chemotherapy/hematopoietic stem cell transplantation (6/19; 32%). Epstein-Barr virus (9; 47%) followed by cytomegalovirus (6; 31%) was the most common viral trigger in our setting. Treatment included antivirals (8; 42%), HLH 2004 protocol (4; 21%), rituximab (4; 21%) and hematopoietic stem cell transplantation (3; 16%). Fourteen children (74%) had full recovery.

CONCLUSIONS

In our small cohort, viral-associated HLH was more frequently encountered in children with genetic predisposition to HLH or children with underlying immunodeficiency. In addition, we found that the outcome is overall good for children who have no genetic predisposition to HLH and children with genetic predisposition who underwent hematopoietic stem cell transplantation.

B-Cell Lymphoma Associated with COVID 19 Infection: A Case Report

PURPOSE

The most commen publications are related about COVID-19 diagnose in hematological malignancy patients, However, here we report a case involving a patient who was diagnosed with B-cell lymphoma while undergoing treatment for COVID-19, including the changes in major clinical symptoms and medical examinations, then explain of the probable causes of the case.

CASE PRESENTATION

A 74-year-old woman with a previous history of oesophageal cancer was admitted to the hospital after having cough and sputum for 15 days. Despite the COVID-19 symptoms, this patient did not have fever at time of the onset. Results of routine blood tests were normal at first but then declined with persistent fever, A whole-body CT examination ruled out the possibility of tumor-metastasis-related fever. This patient had no hepatosplenomegaly or regional lymphadenopathy, and there was no concrete evidence of haemophagocytic lymphohistiocytosis or lymphoma until bone marrow biopsy results confirmed the latter.

CONCLUSION

We describe an uncommen case of COVID-19 who was finally diagnosed with B-cell lymphoma. An awareness of persistent fever and declined routine blood tests caused by haematological malignancies instead of COVID-19 itself can aid in providing appropriate guidelines for management and treatment.

6-Mercaptopurine and Macrophage Activation Syndrome Case Report and Review of the Literature

Macrophage activation syndrome is a life-threatening syndrome of uncontrolled immune activation with variable clinical presentation making early diagnosis difficult. It is often manifested by the development of multi-organ failure due to systemic inflammatory response. Patients with ulcerative colitis (UC) on purine antimetabolites are at high risk for severe myelosuppression due to the mechanism of thiopurine toxicity which potentially contributes to the development of macrophage activation syndrome. We present a case of a 39-year-old woman with a 2-year history of UC previously treated with 6-mercaptopurine (6-MP) and recent COVID-19 infection, who was admitted to our emergency department for C. difficile infection and subsequently developed macrophage activation syndrome. This case report also raises the question of whether abrupt discontinuation of 6-MP may have contributed to the worsening of the patient's symptoms of underlying hemophagocytic lymphohistiocytosis (HLH) and her rapid deterioration. Both macrophage activation syndrome and COVID-19 infection can produce a large number of pro-inflammatory cytokines termed "cytokine storm," but a pro-inflammatory cytokine panel breakdown helps to differentiate between the two. Our case report emphasizes the importance of close monitoring of patients on purine antimetabolite therapy who present with signs and symptoms of systemic toxicity.

Hemophagocytosis, hyper-inflammatory responses, and multiple organ damages in COVID-19-associated hyperferritinemia

Hyperferritinemia comes to light frequently in general practice. However, the characteristics of COVID-19-associated hyperferritinemia and the relationship with the prognosis were not well described. The retrospective study included 268 documented COVID-19 patients. They were divided into the hyperferritinemia group (≥ 500 µg/L) and the non-hyperferritinemia group (< 500 µg/L). The prevalence of fever and thrombocytopenia and the proportion of patients with mechanical ventilator support and in-hospital death were much higher in the hyperferritinemia group (P < 0.001). The hyperferritinemia patients showed higher median IL-6, D-dimer, and hsCRP (P < 0.001) and lowered FIB level (P = 0.036). The hyperferritinemia group had a higher proportion of patients with AKI, ARDS, and CSAC (P < 0.001). According to the multivariate analysis, age, chronic pulmonary disease, and hyperferritinemia were found to be significant independent predictors for in-hospital mortality [HR 1.041 (95% CI 1.015-1.068), P = 0.002; HR 0.427 (95% CI 0.206-0.882), P = 0.022; HR 6.176 (95% CI 2.447-15.587), P < 0.001, respectively]. The AUROC curve was 0.88, with a cut-off value of ≥ 971 µg/L. COVID-19 patients with hyperferritinemia had a high proportion of organ dysfunction, were more likely to show hyper-inflammation, progressed to hemophagocytic lymphohistiocytosis, and indicated a higher proportion of death.

Therapeutic implications of ongoing alveolar viral replication in COVID-19

In patients with moderate-to-severe COVID-19 pneumonia, an aberrant post-viral alveolitis with excessive inflammatory responses and immunothrombosis underpins use of immunomodulatory therapy (eg, corticosteroids and interleukin-6 receptor antagonism). By contrast, immunosuppression in individuals with mild COVID-19 who do not require oxygen therapy or in those with critical disease undergoing prolonged ventilation is of no proven benefit. Furthermore, a window of opportunity is thought to exist for timely immunosuppression in patients with moderate-to-severe COVID-19 pneumonia shortly after clinical presentation. In this Viewpoint, we explore the shortcomings of a universal immunosuppression approach in patients with moderate-to-severe COVID-19 due to disease heterogeneity related to ongoing SARS-CoV-2 replication, which can manifest as RNAaemia in some patients treated with immunotherapy. By contrast, immunomodulatory therapy has overall benefits in patients with rapid SARS-CoV-2 clearance, via blunting of multifaceted, excessive innate immune responses in the lungs, potentially uncontrolled T-cell responses, possible autoimmune responses, and immunothrombosis. We highlight this therapeutic dichotomy to better understand the immunopathology of moderate-to-severe COVID-19, particularly the role of RNAaemia, and to refine therapy choices.

Neutropenic Fever in a Patient With SARS-CoV-2-Induced Hemophagocytic Lymphohistiocytosis (HLH)

Hemophagocytic lymphohistiocytosis (HLH) is a severe systemic inflammatory syndrome that is often fatal. In the adult population, it is believed to develop secondary to immune dysregulation due to rheumatologic, infectious, malignant, and recently, immunomodulatory drugs. It has been well documented that infectious etiologies can lead to HLH however to date there is a paucity of case reports of HLH stemming from the 2019 novel coronavirus (SARS-CoV-2). Furthermore, it is well established that overlap exists between the extensive hyper-inflammatory syndromes produced from both HLH and severe COVID-19 infection. Here, we present a case of COVID-19-associated HLH with recurrent neutropenic fever in a patient with controlled follicular non-Hodgkin lymphoma who received treatment with etoposide after continued hospital admissions with refractory medical treatment.

Hemophagocytic histiocytosis in severe SARS-CoV-2 infection: A bone marrow study

INTRODUCTION

The clinical and laboratory features of severe COVID-19 infection overlap with those of hemophagocytic lymphohistiocytosis (HLH), a hyperinflammatory disorder often associated with several viral infections. The clinical syndrome of HLH encompasses fever, organomegaly, cytopenias, hyperferritinemia, hypertriglyceridemia, raised transaminases, hypofibrinogenemia, absent natural killer (NK) cell activity, increased soluble CD25 and hemophagocytic lymphohistiocytosis in bone marrow, spleen, and lymph nodes.

METHODS

We analyzed clinicopathological and laboratory features of thirteen patients with severe COVID-19 infection suspected to have HLH and found to have hemophagocytic histiocytosis on bone marrow examination (BME).

RESULTS

Five of thirteen (38.46%) patients fulfilled five of eight HLH 2004 criteria and/or had a H-score ≥169. Three (23.08%) satisfied four of eight and remainder five (38.46%) satisfied three of eight HLH 2004 criteria. Fever, raised serum ferritin (13/13, 100%), transaminases (9/13, 69.23%), triglycerides (4/13, 30.76%), cytopenias (5/13, 38.46%), hypofibrinogenemia (2/13, 15.38%), and organomegaly (1/13, 7.69%) were observed in our patients. BME showed hemophagocytic histiocytosis without lymphocytosis in all. Contrary to HLH, lymphocytopenia (11/13, 84.61%), leukocytosis (7/13, 53.84%), neutrophilia (7/13, 53.84%), and hyperfibrinogenemia (7/13, 53.84%) were observed. Serum CRP, LDH, and plasma D-dimer were elevated in all, while serum albumin was decreased in 12 of 13 (92.3%) patients. Five patients recovered with high-dose pulsed corticosteroid therapy.

CONCLUSION

The immune response associated with severe COVID-19 infection is similar to HLH with few differences. HLH should be suspected in severe COVID-19 infection although all patients may not fulfill required HLH diagnostic criteria. BME should be done in suspected cases so that appropriate therapy may be initiated early.

Systemic Lupus Erythematosus With Hemophagocytic Lymphohistiocytosis: Is COVID-19 the Inciting Factor?

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that is characterized by an aberrant immune response leading to immune-mediated damage to tissues. Hemophagocytic lymphohistiocytosis (HLH), a life-threatening condition, consists of a constellation of symptoms caused by excessive immune activation and cytokine storm. HLH is categorized into the primary and secondary form. The secondary form is often referred to as the macrophage activation syndrome. HLH in the background of SLE is a rare and potentially fatal entity. It is often seen in the context of disease flare and is rarely associated with the initial diagnosis of SLE. Severe infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes a cytokine storm characterized by marked elevation of inflammatory markers including ferritin. Here, we describe the case of a young female with an inaugural diagnosis of SLE and features of HLH after a recent SARS-CoV-2 infection.

Pathology updates and diagnostic approaches to hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a complex, often under-recognized hyperinflammatory immune dysregulation syndrome arising in a diverse range of clinical scenarios and conditions. The accurate and timely diagnosis of HLH is crucial for patient survival, and usually requires a high level of clinical suspicion. The histologic corollary to clinical HLH - hemophagocytosis - is neither necessary nor sufficient for the diagnosis of HLH, as it may be seen in a variety of reactive conditions and may be absent in true HLH. Nevertheless, the finding of hemophagocytosis in specific clinical situations should prompt consideration of HLH and further testing to exclude the condition. While traditionally described in bone marrow, identification of hemophagocytosis in other tissues, including lymphoid, splenic, liver, or neural tissue, can be an important asset to the overall recognition of HLH. In this review we discuss the underlying pathophysiology and etiologies of HLH, morphologic aspects of hemophagocytosis and its associated histologic findings in different tissues, and give a brief overview of diagnostic criteria and clinical evaluation.

Association of lymphocyte subsets with mortality in severe COVID-19 pneumonia patients

Background

Few studies have investigated the alterations in the T and B cell counts and related subgroups in pulmonary infections especially COVID‐19. Here, we aimed to evaluate total T and B lymphocytes and T cell subgroup counts to find the possible correlation between number of these cells and severity and mortality in COVID‐19 patients.

Methods

This study was performed on 40 patients with severe COVID‐19 infection confirmed by reverse transcription‐polymerase chain reaction (RT‐PCR) and chest HRCT in August 2020. By the time of admission, T lymphocytes profile in peripheral blood was investigated using multicolor flow cytometry. The total number of T lymphocytes, CD4+ T cells, CD8+ T cells, and B lymphocytes were calculated. Expression of CD2, CD3, CD5, and CD7 as pan T cell surface markers and expression of CD38 and HLA‐DR as activated markers on T lymphocytes were also evaluated.

Results

Nine patients (22.5%) died during the study and 16 patients (40%) were admitted to ICU. Deceased patients demonstrated lower amounts of T cell count and CD4+ T cell count (with a marginal difference (p = 0.07)) compared with survived patients at the time of admission. The chance of mortality was significantly higher for patients with CD7 loss (OR = 14.89). A marginally significant relationship was also indicated between CD4<200/ml and mortality (OR = 8.65), but no other significant relationships were observed between variables and ICU admission.

Conclusion

Altogether, CD7 loss on T lymphocytes and CD4+ T cell count below 200/ml revealed a significant relationship with mortality. Considering T lymphocytes and T cell subgroup count could have a predictive value for patients suffering from COVID‐19.

Haemophagocytic lymphohistiocytosis in pregnancy: a pertinent case during the COVID-19 pandemic

Haemophagocytic lymphohistiocytosis (HLH) is a rare, often fatal disease, and presents a diagnostic challenge in the pregnant patient. This challenge is particularly relevant during the current COVID-19 pandemic. We present a case of HLH in a pregnant woman presenting with fever predating the COVID-19 pandemic. A 33-year-old, gravida 2, para 1 at 27 weeks’ gestation presented with fever, transaminitis, thrombocytopenia and elevated ferritin. After treatment according to the HLH-94 protocol, caesarean delivery and weeks of intensive care, the patient recovered fully. With prompt diagnosis and a multispecialty team at our tertiary care facility, she and her baby overcame a dire prognosis. HLH should be considered in pregnant patients presenting with a febrile illness. Particularly in cases of severe COVID-19, secondary HLH must be considered as an associated diagnosis.

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.

The Use of CytoSorb Therapy in Critically Ill COVID-19 Patients: Review of the Rationale and Current Clinical Experiences

The COVID-19 pandemic has led to the biggest global health crisis of our lifetime. There is accumulating evidence that a substantial number of critically ill COVID-19 patients exhibit a dysregulated host response manifesting as cytokine storm or cytokine release syndrome, which in turn contributes to the high observed rates of mortality. Just as in other hyperinflammatory conditions, extracorporeal cytokine removal may have potential beneficial effects in this subgroup of COVID-19 patients. The CytoSorb blood purification device is the most extensively investigated cytokine removal platform with considerable evidence suggesting that early intervention can provide rapid hemodynamic stabilization and improvement in vital organ functions. The purpose of this review is to provide an overview of the pathophysiological background of hyperinflammation in COVID-19 and to summarize the currently available evidence on the effects of hemoadsorption in these patients.

Critical Determinants of Cytokine Storm and Type I Interferon Response in COVID-19 Pathogenesis

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), a rapidly evolving pandemic worldwide with at least 68 million COVID-19-positive cases and a mortality rate of about 2.2%, as of 10 December 2020. About 20% of COVID-19 patients exhibit moderate to severe symptoms. Severe COVID-19 manifests as acute respiratory distress syndrome (ARDS) with elevated plasma proinflammatory cytokines, including interleukin 1β (IL-1β), IL-6, tumor necrosis factor α (TNF-α), C-X-C motif chemokine ligand 10 (CXCL10/IP10), macrophage inflammatory protein 1 alpha (MIP-1α), and chemokine (C-C motif) ligand 2 (CCL2), with low levels of interferon type I (IFN-I) in the early stage and elevated levels of IFN-I during the advanced stage of COVID-19. Most of the severe and critically ill COVID-19 patients have had preexisting comorbidities, including hypertension, diabetes, cardiovascular diseases, and respiratory diseases. These conditions are known to perturb the levels of cytokines, chemokines, and angiotensin-converting enzyme 2 (ACE2), an essential receptor involved in SARS-CoV-2 entry into the host cells. ACE2 downregulation during SARS-CoV-2 infection activates the angiotensin II/angiotensin receptor (AT1R)-mediated hypercytokinemia and hyperinflammatory syndrome. However, several SARS-CoV-2 proteins, including open reading frame 3b (ORF3b), ORF6, ORF7, ORF8, and the nucleocapsid (N) protein, can inhibit IFN type I and II (IFN-I and -II) production. Thus, hyperinflammation, in combination with the lack of IFN responses against SARS-CoV-2 early on during infection, makes the patients succumb rapidly to COVID-19. Therefore, therapeutic approaches involving anti-cytokine/anti-cytokine-signaling and IFN therapy would favor the disease prognosis in COVID-19. This review describes critical host and viral factors underpinning the inflammatory "cytokine storm" induction and IFN antagonism during COVID-19 pathogenesis. Therapeutic approaches to reduce hyperinflammation and their limitations are also discussed.

Risk of COVID-19 in Chagas Disease Patients: What Happen with Cardiac Affectations?

BACKGROUND

Chagas disease is considered a neglected tropical disease. The acute phase of Chagas disease is characterized by several symptoms: fever, fatigue, body aches, headache and cardiopathy's. Chronic phase could be asymptomatic or symptomatic with cardiac compromise. Since the emergence of the pandemic caused by the SARS-CoV-2 virus, the cardiovascular involvement has been identified as a complication commonly reported in coronavirus disease 2019 (COVID-19). Due to the lack of knowledge of the cardiac affectations that this virus could cause in patients with Chagas disease, the aim of this review is to describe the possible cardiac affectations, as well as the treatment and recommendations that patients with both infections should carry out.

METHODS

The authors revised the recent and relevant literature concerning the topic and discussed advances and limitations of studies on COVID-19 and their impact in Chagas disease patients, principally with cardiac affectations.

RESULTS

There currently exists little information about the consequences that Chagas disease patients can suffer when they are infected with COVID-19.

CONCLUSIONS

This review highlights the emerging challenges of access to medical care and future research needs in order to understand the implications that co-infections (SARS-CoV-2 or other viruses) can generate in Chagas disease-infected people.

Cytokine Storm of COVID-19 and Its Impact on Patients with and without Chronic Liver Disease

The coronavirus pandemic has resulted in increased rates of hepatic decompensation, morbidity and mortality in patients suffering from existing liver disease, and deranged liver biochemistries in those without liver disease. In patients with cirrhosis with coronavirus disease 2019 (COVID-19), new onset organ failures manifesting as acute-on-chronic liver failure have also been reported. The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) also directly binds to enterocytes and cholangiocytes via the angiotensin converting enzyme receptor 2, although the lung remains the portal of entry. Superadded with the COVID-19 related bystander hepatitis, a systemic inflammatory response is noted due to unregulated macrophage activation syndrome and cytokine storm. However, the exact definition and diagnostic criteria of the 'cytokine storm' in COVID-19 are yet unclear. In addition, inflammatory markers like C-reactive protein, ferritin, D-dimer and procalcitonin are frequently elevated. This in turn leads to disease progression, activation of the coagulation cascade, vascular microthrombi and immune-mediated injury in different organ systems. Deranged liver chemistries are also noted due to the cytokine storm, and synergistic hypoxic or ischemic liver injury, drug-induced liver injury, and use of hepatotoxic antiviral agents all contribute to deranged liver chemistry. Control of an unregulated cytokine storm at an early stage may avert disease morbidity and mortality. Several immunomodulator drugs and repurposed immunosuppressive agents have been used in COVID-19 with varying degrees of success.

Early hematological indicators of severe COVID-19 disease in hospitalized patients: Data from a South Asian population

Introduction

Outbreak of corona virus disease in 2019 (COVID‐19) has resulted in significant morbidity and mortality worldwide. Our aim is to document hematological parameters of patients with COVID‐19 during initial stage of diagnosis and to identify early hematological indicators of severe infection.

Materials and methods

This retrospective study was conducted at Shifa International Hospital, Pakistan from April to November 2020. Patients hospitalized with COVID‐19, diagnosed on RT‐PCR and had a complete blood count (CBC) done within 48 hours of diagnosis were included. Data was analyzed using IBM^® SPSS Statistics.

Results

A total of 425 patients were included in this study out of whom 272(64%) were males. The mean age was 55.61 ± 17.84 years. 95 patients (22.4%) had normal blood counts within 48 hours of COVID‐19 diagnosis. Cytopenias were seen in 193(45.4%) patients. There were 75(17.6%) mortalities during the study period. Chi‐square test showed that thrombocytopenia, lymphopenia and neutrophilic leucocytosis were significantly associated with mortality (P = .037, P < .001, P < .001 respectively) and need for ventilator (P = .009, P < .001, P < .001, respectively). Neutrophilia was also associated with development of Acute Respiratory Distress Syndrome (P < .001). On ROC analysis, Neutrophil‐to‐Lymphocyte Ratio yielded an area under the curve (AUC) of 0.693 and 0.660 for the outcomes mortality and need for ventilator, respectively. For a subset of 288 patients who had D‐dimer levels checked within 48 hours of COVID‐19 diagnosis, the AUC for mortality and ventilator need was 0.708 and 0.671, respectively.

Conclusion

Hematological indices are vital indicators in the prognosis and risk stratification of COVID‐19 during initial stages of disease.

Haemophagocytic syndrome and COVID-19

Primary and secondary haemophagocytic lymphohistiocytosis (HLH) are hyperferritinaemic hyperinflammatory syndromes with a common terminal pathway triggered by different etiopathogenetic factors. HLH is characterised by a decreased capacity of interferon gamma production with an activated NK phenotype profile similar to other hyperinflammatory syndromes. Viruses are closely linked to the development of HLH as infectious triggers, and the break of tolerance to self-antigens is considered a critical mechanism involved in the development of immune-mediated conditions triggered by viral infections. Emerging studies in patients with COVID-19 are suggesting a key role of monocytes/macrophages in the pathogenesis of this viral infection, and there is a significant overlap between several features reported in severe COVID-19 and the features included in the HLH-2004 diagnostic criteria. Therefore, SARS-Cov-2, as other respiratory viruses, may also be considered a potential etiological trigger of HLH. The frequency of HLH in adult patients with severe COVID-19 is lower than 5%, although this figure could be underestimated considering that most reported cases lacked information about some specific criteria (mainly the histopathological criteria and the measurement of NK cell function and sCD25 levels). Because HLH is a multi-organ syndrome, the diagnostic approach in a patient with severe COVID-19 in whom HLH is suspected must be carried out in a syndromic and holistic way, and not in the light of isolated clinical or laboratory features. In COVID-19 patients presenting with persistent high fever, progressive pancytopenia, and hepatosplenic involvement, together with the characteristic triad of laboratory abnormalities (hyperferritinaemia, hypertriglyceridaemia, and hypofibrinogenaemia), the suspicion of HLH is high, and the diagnostic workup must be completed with specific immunological and histopathological studies.

IL-6 modulation for COVID-19: the right patients at the right time?

The ongoing pandemic caused by the novel coronavirus SARS-CoV-2 has disrupted the global economy and strained healthcare systems to their limits. After the virus first emerged in late 2019, the first intervention that demonstrated significant reductions in mortality for severe COVID-19 in large-scale trials was corticosteroids. Additional options that may reduce the burden on the healthcare system by reducing the number of patients requiring intensive care unit support are desperately needed, yet no therapy has conclusively established benefit in randomized studies for the management of moderate or mild cases of disease. Severe COVID-19 disease is characterized by a respiratory distress syndrome accompanied by elevated levels of several systemic cytokines, in a profile that shares several features with known inflammatory pathologies such as hemophagocytic lymphohistiocytosis and cytokine release syndrome secondary to chimeric antigen receptor (CAR) T cell therapy. Based on these observations, modulation of inflammatory cytokines, particularly interleukin (IL)-6, was proposed as a strategy to mitigate severe disease. Despite encouraging recoveries with anti-IL-6 agents, especially tocilizumab from single-arm studies, early randomized trials returned mixed results in terms of clinical benefit with these interventions. Later, larger trials such as RECOVERY and REMAP-CAP, however, are establishing anti-IL-6 in combination with steroids as a potential option for hypoxic patients with evidence of hyperinflammation. We propose that a positive feedback loop primarily mediated by macrophages and monocytes initiates the inflammatory cascade in severe COVID-19, and thus optimal benefit with anti-IL-6 therapies may require intervention during a finite window of opportunity at the outset of hyperinflammation but before fulminant disease causes irreversible tissue damage-as defined clinically by C reactive protein levels higher than 75 mg/L.

Death of unknown cause? Post-mortem diagnosis of fulminant course of an EBV-associated secondary hemophagocytic lymphohistiocytosis

HLH is a life-threatening disease, which is characterized by a dysregulated immune response with uncontrolled T cell and macrophage activation. The often fulminant course of the disease needs a fast diagnostic work-up to initiate as soon as possible the appropriate therapy. We present herein the case of a 71-year-old patient with rapidly progressive hyperinflammatory syndrome, which post mortem resulted in the diagnosis of EBV-associated HLH. With this case report, we intend to highlight the relevance of the HScore in the diagnosis of HLH, to create a greater awareness for EBV as a trigger of HLH, and to demonstrate the importance of treating EBV-associated HLH as early as possible.

Overview of the Haematological Effects of COVID-19 Infection

From its early origins, COVID-19 has spread extensively and was declared a global pandemic by the World Health Organization in March of 2020. Although initially thought to be predominantly a respiratory infection, more recent evidence points to a multisystem systemic disease which is associated with numerous haematological and immunological disturbances in addition to its other effects. Here we review the current knowledge on the haematological effects of COVID-19.

Prediction of Sepsis in COVID-19 Using Laboratory Indicators

Background

The outbreak of coronavirus disease 2019 (COVID-19) has become a global public health concern. Many inpatients with COVID-19 have shown clinical symptoms related to sepsis, which will aggravate the deterioration of patients’ condition. We aim to diagnose Viral Sepsis Caused by SARS-CoV-2 by analyzing laboratory test data of patients with COVID-19 and establish an early predictive model for sepsis risk among patients with COVID-19.

Methods

This study retrospectively investigated laboratory test data of 2,453 patients with COVID-19 from electronic health records. Extreme gradient boosting (XGBoost) was employed to build four models with different feature subsets of a total of 69 collected indicators. Meanwhile, the explainable Shapley Additive ePlanation (SHAP) method was adopted to interpret predictive results and to analyze the feature importance of risk factors.

Findings

The model for classifying COVID-19 viral sepsis with seven coagulation function indicators achieved the area under the receiver operating characteristic curve (AUC) 0.9213 (95% CI, 89.94–94.31%), sensitivity 97.17% (95% CI, 94.97–98.46%), and specificity 82.05% (95% CI, 77.24–86.06%). The model for identifying COVID-19 coagulation disorders with eight features provided an average of 3.68 (±) 4.60 days in advance for early warning prediction with 0.9298 AUC (95% CI, 86.91–99.04%), 82.22% sensitivity (95% CI, 67.41–91.49%), and 84.00% specificity (95% CI, 63.08–94.75%).

Interpretation

We found that an abnormality of the coagulation function was related to the occurrence of sepsis and the other routine laboratory test represented by inflammatory factors had a moderate predictive value on coagulopathy, which indicated that early warning of sepsis in COVID-19 patients could be achieved by our established model to improve the patient’s prognosis and to reduce mortality.

Bacterial Superinfections Among Persons With Coronavirus Disease 2019: A Comprehensive Review of Data From Postmortem Studies

BACKGROUND

Limited clinical data suggest a ~16% prevalence of bacterial superinfections among critically ill patients with coronavirus disease 2019 (COVID-19).

METHODS

We reviewed postmortem studies of patients with COVID-19 published in English through September 26, 2020, for histopathologic findings consistent with bacterial lung infections.

RESULTS

Worldwide, 621 patients from 75 studies were included. The quality of data was uneven, likely because identifying superinfections was not a major objective in 96% (72/75) of studies. Histopathology consistent with a potential lung superinfection was reported in 32% (200/621) of patients (22-96 years old; 66% men). Types of infections were pneumonia (95%), abscesses or empyema (3.5%), and septic emboli (1.5%). Seventy-three percent of pneumonias were focal rather than diffuse. The predominant histopathologic findings were intra-alveolar neutrophilic infiltrations that were distinct from those typical of COVID-19-associated diffuse alveolar damage. In studies with available data, 79% of patients received antimicrobial treatment; the most common agents were beta-lactam/beta-lactamase inhibitors (48%), macrolides (16%), cephalosoprins (12%), and carbapenems (6%). Superinfections were proven by direct visualization or recovery of bacteria in 25.5% (51/200) of potential cases and 8% of all patients in postmortem studies. In rank order, pathogens included Acinetobacter baumannii, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Lung superinfections were the cause of death in 16% of potential cases and 3% of all patients with COVID-19.

CONCLUSIONS

Potential bacterial lung superinfections were evident at postmortem examination in 32% of persons who died with COVID-19 (proven, 8%; possible, 24%), but they were uncommonly the cause of death.

Unique immunological profile in patients with COVID-19

The relationship between severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and host immunity is poorly understood. We performed an extensive analysis of immune responses in 32 patients with severe COVID-19, some of whom succumbed. A control population of healthy subjects was included. Patients with COVID-19 had an altered distribution of peripheral blood lymphocytes, with an increased proportion of mature natural killer (NK) cells and low T-cell numbers. NK cells and CD8⁺ T cells overexpressed T-cell immunoglobulin and mucin domain-3 (TIM-3) and CD69. NK cell exhaustion was attested by increased frequencies of programmed cell death protein 1 (PD-1) positive cells and reduced frequencies of natural killer group 2 member D (NKG2D)-, DNAX accessory molecule-1 (DNAM-1)- and sialic acid-binding Ig-like lectin 7 (Siglec-7)-expressing NK cells, associated with a reduced ability to secrete interferon (IFN)γ. Patients with poor outcome showed a contraction of immature CD56^bright and an expansion of mature CD57⁺ FcεRIγ^neg adaptive NK cells compared to survivors. Increased serum levels of IL-6 were also more frequently identified in deceased patients compared to survivors. Of note, monocytes secreted abundant quantities of IL-6, IL-8, and IL-1β which persisted at lower levels several weeks after recovery with concomitant normalization of CD69, PD-1 and TIM-3 expression and restoration of CD8⁺ T cell numbers. A hyperactivated/exhausted immune response dominate in severe SARS-CoV-2 infection, probably driven by an uncontrolled secretion of inflammatory cytokines by monocytes. These findings unveil a unique immunological profile in COVID-19 patients that will help to design effective stage-specific treatments for this potentially deadly disease.

A fine line between macrophage activation syndrome and multisystem inflammatory syndrome in children - literature review based on two case reports

Multisystem inflammatory syndrome in children is a newly described condition temporarily associated with severe acute respiratory syndrome coronavirus 2. The primary observations indicated coronavirus disease 2019 infection in children to be mild. However, recent reports have revealed a correlation between multisystem inflammatory symptoms and coronavirus infection. The manifestation of the disease is similar to Kawasaki disease, toxic shock syndrome and macrophage activation syndrome. Treatment includes intravenous corticosteroids, immunoglobulin and biological therapy (anakinra, tocilizumab, infliximab).

In this article we compare world reports of multisystem inflammatory syndrome in children to case reports of two patients who were hospitalized recently at the Department of Paediatric Cardiology and Rheumatology. In the course of diagnostics they presented numerous symptoms which required differentiation from multisystem inflammatory syndrome in children.

Demystifying Excess Immune Response in COVID-19 to Reposition an Orphan Drug for Down-Regulation of NF-κB: A Systematic Review

The immunological findings from autopsies, biopsies, and various studies in COVID-19 patients show that the major cause of morbidity and mortality in COVID-19 is excess immune response resulting in hyper-inflammation. With the objective to review various mechanisms of excess immune response in adult COVID-19 patients, Pubmed was searched for free full articles not related to therapeutics or co-morbid sub-groups, published in English until 27.10.2020, irrespective of type of article, country, or region. Joanna Briggs Institute's design-specific checklists were used to assess the risk of bias. Out of 122 records screened for eligibility, 42 articles were included in the final review. The review found that eventually, most mechanisms result in cytokine excess and up-regulation of Nuclear Factor-κB (NF-κB) signaling as a common pathway of excess immune response. Molecules blocking NF-κB or targeting downstream effectors like Tumour Necrosis Factor α (TNFα) are either undergoing clinical trials or lack specificity and cause unwanted side effects. Neutralization of upstream histamine by histamine-conjugated normal human immunoglobulin has been demonstrated to inhibit the nuclear translocation of NF-κB, thereby preventing the release of pro-inflammatory cytokines Interleukin (IL) 1β, TNF-α, and IL-6 and IL-10 in a safer manner. The authors recommend repositioning it in COVID-19.

Cytologic findings in effusions from patients with SARS-CoV-2 infection

Introduction

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is associated with “flu-like” upper respiratory tract symptoms and pneumonia. Body cavity effusions develop in a subset of patients with advanced disease. Although SARS-CoV-2 is known to be present in certain body fluids (eg, blood) of COVID patients, it remains unclear if body cavity fluids are sites of infection. Our aim was to characterize the cytologic and clinical findings in COVID-19 patients with effusions.

Materials and methods

A record search for all cases of body cavity effusion cytology in SARS-CoV-2 positive patients from March 1, 2020, to September 1, 2020, was performed. Clinical history, fluid chemical analysis, cytologic findings, and patient outcomes were recorded. All cytology slides were reviewed. In situ hybridization (ISH) targeting SARS-CoV-2 spike protein transcript (V-nCoV2019-S) was performed on cell block material in all cases.

Results

A total of 17 effusion cytology cases were identified among 15 COVID patients, including 13 pleural, 2 pericardial, and 2 peritoneal. Most (13 of 15) patients were hospitalized for COVID complications. Eight patients died during hospitalization, 7 from COVID complications. All fluids were transudative by protein criteria. Lymphocytic or histiocytic inflammation predominated in 12 of 17 cases. Five exhibited hemophagocytosis. No viral cytopathic changes or extra-medullary megakaryocytes were seen. Viral RNA was not detected in any case by ISH.

Conclusions

Body cavity effusion is an ominous finding in patients with advanced COVID-19 disease. Such effusions tend to be transudative with lymphohistiocytic inflammation, and commonly exhibit hemophagocytosis, an otherwise rare finding in effusion cytologies. No direct infection of cellular elements by SARS-CoV-2 was identified by ISH.

Highlights of the Management of Adult Histiocytic Disorders: Langerhans Cell Histiocytosis, Erdheim-Chester Disease, Rosai-Dorfman Disease, and Hemophagocytic Lymphohistiocytosis

Histiocytic disorders are an exceptionally rare group of diseases with diverse manifestations and a paucity of approved treatments, thereby leading to various challenges in their diagnosis and management. With the discovery of novel molecular targets and the incorporation of targeted agents in the management of various adult histiocytic disorders, their management has become increasingly complex. In an attempt to improve the understanding of the clinical features and management of common adult histiocytic disorders (Langerhans cell histiocytosis, Erdheim-Chester disease, Rosai-Dorfman disease, and hemophagocytic lymphohistiocytosis), we created this document based on existing literature and expert opinion.