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

Low Percentage of Perforin-Expressing NK Cells during Severe SARS-CoV-2 Infection: Consumption Rather than Primary Deficiency

Genetic defects in the ability to deliver effective perforin have been reported in patients with hemophagocytic lymphohistiocytosis. We tested the hypothesis that a primary perforin deficiency might also be causal in severe SARS-CoV-2 infection. We recruited 54 volunteers confirmed as being SARS-CoV-2-infected by RT-PCR and admitted to intensive care units or non-intensive care units and age- and sex-matched healthy controls. Compared with healthy controls, the percentage of perforin-expressing CD3-CD56+ NK cells quantified by flow cytometry was low in COVID-19 patients (69.9 ± 17.7 versus 78.6 ± 14.6%, p = 0.026). There was no correlation between the proportions of perforin-positive NK cells and T8 lymphocytes. Moreover, the frequency of NK cells producing perforin was neither linked to disease severity nor predictive of death. Although IL-6 is known to downregulate perforin production in NK cells, we did not find any link between perforin expression and IL-6 plasma level. However, we unveiled a negative correlation between the degranulation marker CD107a and perforin expression in NK cells (r = -0.488, p = 10-4). PRF1 gene expression and the frequency of NK cells harboring perforin were normal in patients 1 y after acute SARS-CoV-2 infection. A primary perforin defect does not seem to be a driver of COVID-19 because NK perforin expression is 1) linked neither to T8 perforin expression nor to disease severity, 2) inversely correlated with NK degranulation, and 3) normalized at distance from acute infection. Thus, the cause of low frequency of perforin-positive NK cells appears, rather, to be consumption.

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.

Hemophagocytic Lymphohistiocytosis Following COVID-19 Infection

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been associated with multiple inflammatory symptoms involving several organ systems, including hematologic manifestations. Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening syndrome caused by excessive inflammation in the absence of immune regulation. We present the case of a patient with HLH secondary to dysregulated inflammatory response following COVID-19; we also describe the diagnostic and management challenges associated with the condition.

Corticosteroid treatment in severe patients with SARS-CoV-2 and chronic HBV co-infection: a retrospective multicenter study

Background

The impact of corticosteroids on patients with severe coronavirus disease 2019 (COVID-19)/chronic hepatitis B virus (HBV) co-infection is currently unknown. We aimed to investigate the association of corticosteroids on these patients.

Methods

This retrospective multicenter study screened 5447 confirmed COVID-19 patients hospitalized between Jan 1, 2020 to Apr 18, 2020 in seven centers in China, where the prevalence of chronic HBV infection is moderate to high. Severe patients who had chronic HBV and acute SARS-cov-2 infection were potentially eligible. The diagnosis of chronic HBV infection was based on positive testing for hepatitis B surface antigen (HBsAg) or HBV DNA during hospitalization and a medical history of chronic HBV infection. Severe patients (meeting one of following criteria: respiratory rate > 30 breaths/min; severe respiratory distress; or SpO2 ≤ 93% on room air; or oxygen index < 300 mmHg) with COVID-19/HBV co-infection were identified. The bias of confounding variables on corticosteroids effects was minimized using multivariable logistic regression model and inverse probability of treatment weighting (IPTW) based on propensity score.

Results

The prevalence of HBV co-infection in COVID-19 patients was 4.1%. There were 105 patients with severe COVID-19/HBV co-infections (median age 62 years, 57.1% male). Fifty-five patients received corticosteroid treatment and 50 patients did not. In the multivariable analysis, corticosteroid therapy (OR, 6.32, 95% CI 1.17–34.24, P = 0.033) was identified as an independent risk factor for 28-day mortality. With IPTW analysis, corticosteroid treatment was associated with delayed SARS-CoV-2 viral RNA clearance (OR, 2.95, 95% CI 1.63–5.32, P < 0.001), increased risk of 28-day and in-hospital mortality (OR, 4.90, 95% CI 1.68–14.28, P = 0.004; OR, 5.64, 95% CI 1.95–16.30, P = 0.001, respectively), and acute liver injury (OR, 4.50, 95% CI 2.57–7.85, P < 0.001). Methylprednisolone dose per day and cumulative dose in non-survivors were significantly higher than in survivors.

Conclusions

In patients with severe COVID-19/HBV co-infection, corticosteroid treatment may be associated with increased risk of 28-day and in-hospital mortality.

Development of Laboratory Parameters-Based Formulas in Predicting Short Outcomes for Adult Hemophagocytic Lymphohistiocytosis Patients with Different Underlying Diseases

PURPOSE

Hemophagocytic lymphohistiocytosis (HLH) is a severe disease with high mortality. The purpose of this investigation was to build models to predict 30-day death in total and subgroup HLH patients based on available and cheap laboratory parameters.

METHOD

The research contained 431 adults HLH patients from January 2015 to September 2021 in the hospital. Logistic regression and receiver operating characteristic (ROC) were utilized to build models.

RESULTS

Results suggested that age, ferritin, lymphocyte (LY), international normalized ratio (INR), thrombin time (TT), globulin, uric acid (UA), chloride, activated partial thromboplastin time (APTT), aspartate aminotransferase (AST), triglycerides (TG), total bilirubin (TB), and indirect bilirubin (IB) were independent factors in HLH and subgroups. Then, models adapted to patients with different underlying diseases were established based on these factors. Area under curve (AUC) of these models was excellent: HLH patients: 0.838 (p < 0.001); infection-associated HLH (I-HLH) patients: 0.913 (p < 0.001); malignancy-associated HLH (M-HLH): 0.921 (p < 0.001) and 0.809 (p < 0.001) for two or more different etiologies-associated HLH (Mix-HLH patients). In addition, UA, TT, and chloride were firstly confirmed as independent factors in adult HLH.

CONCLUSION

Four models depending on biomarkers that available and affordable in clinical practice were built. With these models, high-risk patients with different underlying diseases could be easily identified.

Case Report: Secondary Hemophagocytic Lymphohistiocytosis (sHLH) and Candida auris Fungemia in Post-acute COVID-19 Syndrome: A Clinical Challenge

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes a disease (COVID-19) with multisystem involvement. The world is now entering a phase of post-COVID-19 manifestations in this pandemic. Secondary hemophagocytic lymphohistiocytosis (sHLH) is a life-threatening hyperinflammatory event triggered by viral infections, including SARS-CoV-2. Both Multisystem Inflammatory Syndrome-Adults (MIS-A) and Cytokine Storm Syndrome (CSS) are considered close differentials of sHLH and add to the spectrum of Post-acute COVID-19 syndrome (PACS). In this report, we presented the case of a middle-aged Asian man who was initially discharged upon recovery from severe COVID-19 infection after 17 days of hospitalization to a private institute and later came to our hospital 13 days post-discharge. Here, he was diagnosed with sHLH, occurring as an extension of CSS, with delayed presentation falling within the spectrum of PACS. The diagnosis of sHLH was made holistically with the HLH-2004 criteria. Our patient initially responded to intravenous immunoglobulin (IVIG) and dexamethasone, later complicated by disseminated Candida auris infection and had a fatal outcome. Though many cases of HLH during active COVID-19 and a few cases post COVID-19 recovery have been reported, based on H-score, which has limitations as a diagnostic tool. We report the first case report of post-COVID-19 sHLH using the HLH-2004 criteria, complicated by disseminated Candidemia, emphasizing that the care of patients with COVID-19 does not conclude at the time of hospital discharge. We highlight the importance of surveillance in the post-COVID phase for early detection of sHLH which may predispose to fatal opportunistic infections (OIs).

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.

COVID-19 associated EBV reactivation and effects of ganciclovir treatment

Background

Systemic reactivation of Epstein–Barr virus (EBV) may occur in novel coronavirus disease 2019 (COVID‐19) caused by the severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2). However, the clinical consequences of EBV reactivation remain uncertain.

Methods

In this retrospective study, we screened 1314 patients with confirmed COVID‐19 who died or were discharged between January 1, 2020 and March 12, 2020, in Wuhan Infectious Disease Hospital, Wuhan, China. Patients who had complete data for EBV serology and cytomegalovirus (CMV) serology were eligible. Serum levels of viral capsid antigen (VCA)‐immunoglobulin G (IgG), Epstein–Barr nuclear antigen‐IgG, VCA‐IgM, early antigen (EA)‐IgG, CMV‐IgG, and CMV‐IgM were compared between survivors and nonsurvivors. Dynamic changes of laboratory tests and outcomes were compared in patients with and without ganciclovir treatment. We used 1:1 matching based on age, gender, and illness severity to balance baseline characteristics.

Results

EBV reactivation was present in 55 of 217 patients. EBV reactivation was associated with age (57.91 [13.19] vs. 50.28 [12.66] years, p < .001), female gender (31 [56%] vs. 60 [37%], p = .02). Patients with EBV reactivation have statistically nonsignificant higher mortality rate (12 [22%] vs. 18 [11%], p = .08). EA‐IgG levels were significantly higher in nonsurvivors than in survivors (median difference: −0.00005, 95% confidence interval, CI [−3.10, 0.00], p = .05). As compared to patients with COVID‐19 who did not receive ganciclovir therapy, ganciclovir‐treated patients had improved survival rate (0.98, 95% CI [0.95, 1.00] vs. 0.88, 95% CI [0.81, 0.95], p = .01). Hemoglobin (p < .001) and prealbumin (p = .02) levels were significantly higher in ganciclovir‐treated patients.

Conclusion

A high proportion of COVID‐19 patients had EBV reactivation that may be associated with an increased risk of death. Whether treatment with ganciclovir may decrease the mortality of COVID‐19 patients complicated with EBV reactivation warrants to be addressed in a placebo‐controlled randomized trial in the future.

COVID-19-A Trigger Factor for Severe Immune-Mediated Thrombocytopenia in Active Rheumatoid Arthritis

Thrombocytopenia is defined as a platelet count below 150,000/mm³ for adults. There is still controversy about whether individuals with platelet counts of 100,000/mm³ to 150,000/mm³ should be classified as having genuine thrombocytopenia or borderline thrombocytopenia. Thrombocytopenia is considered mild when the platelet count is between 70,000 and 150,000/mm³ and severe if the count is less than 20,000/mm³. Thrombocytopenia in rheumatoid arthritis is a rare complication, with an incidence estimated between 3 and 10%. The main etiological aspects include drug-induced thrombocytopenia and immune thrombocytopenic purpura. The most common hematological abnormalities in SARS-CoV-2 infection are lymphopenia and thrombocytopenia. It has been observed that the severity of thrombocytopenia correlates with the severity of the infection, being a poor prognosis indicator and a risk factor for mortality. COVID-19 can stimulate the immune system to destroy platelets by increasing the production of autoantibodies and immune complexes. Autoimmunity induced by viral infections can be related to molecular mimicry, cryptic antigen expression and also spreading of the epitope. During the COVID-19 pandemic, it is of great importance to include the SARS-CoV-2 infection in differential diagnoses, due to the increased variability in forms of presentation of this pathology. In this review, our aim is to present one of the most recently discovered causes of thrombocytopenia, which is the SARS-CoV-2 infection and the therapeutic challenges it poses in association with an autoimmune disease such as rheumatoid arthritis.

Active pulmonary tuberculosis and coronavirus disease 2019: A systematic review and meta-analysis

OBJECTIVE

The proportion of COVID-19 patients having active pulmonary tuberculosis, and its impact on COVID-19 related patient outcomes, is not clear. We conducted this systematic review to evaluate the proportion of patients with active pulmonary tuberculosis among COVID-19 patients, and to assess if comorbid pulmonary tuberculosis worsens clinical outcomes in these patients.

METHODS

We queried the PubMed and Embase databases for studies providing data on (a) proportion of COVID-19 patients with active pulmonary tuberculosis or (b) severe disease, hospitalization, or mortality among COVID-19 patients with and without active pulmonary tuberculosis. We calculated the proportion of tuberculosis patients, and the relative risk (RR) for each reported outcome of interest. We used random-effects models to summarize our data.

RESULTS

We retrieved 3,375 citations, and included 43 studies, in our review. The pooled estimate for proportion of active pulmonary tuberculosis was 1.07% (95% CI 0.81%-1.36%). COVID-19 patients with tuberculosis had a higher risk of mortality (summary RR 1.93, 95% CI 1.56-2.39, from 17 studies) and for severe COVID-19 disease (summary RR 1.46, 95% CI 1.05-2.02, from 20 studies), but not for hospitalization (summary RR 1.86, 95% CI 0.91-3.81, from four studies), as compared to COVID-19 patients without tuberculosis.

CONCLUSION

Active pulmonary tuberculosis is relatively common among COVID-19 patients and increases the risk of severe COVID-19 and COVID-19-related mortality.

Iron metabolism in infections: Focus on COVID-19

Iron is a micronutrient essential for a wide range of metabolic processes in virtually all living organisms. During infections, a battle for iron takes place between the human host and the invading pathogens. The liver peptide hepcidin, which is phylogenetically and structurally linked to defensins (antimicrobial peptides of the innate immunity), plays a pivotal role by subtracting iron to pathogens through its sequestration into host cells, mainly macrophages. While this phenomenon is well studied in certain bacterial infections, much less is known regarding viral infections. Iron metabolism also has implications on the functionality of cells of the immune system. Once primed by the contact with antigen presenting cells, lymphocytes need iron to sustain the metabolic burst required for mounting an effective cellular and humoral response. The COVID-19 pandemic has boosted an amount of clinical and translational research over the possible influences of nutrients on SARS-CoV-2 infection, in terms of either susceptibility or clinical course. Here we review the intersections between iron metabolism and COVID-19, belonging to the wider domain of the so-called “nutritional immunity”. A better understanding of such connections has potential broad implications, either from a mechanistic standpoint, or for the development of more effective strategies for managing COVID-19 and possible future pandemics.