Ferritin in the antiphospholipid syndrome and its catastrophic variant (cAPS)

Catastrophic Antiphospholipid Syndrome: A Complex Diagnosis in the Setting of Lupus

This case report aims to highlight the importance of keeping catastrophic antiphospholipid syndrome (CAPS) high on the list of differentials in patients with lupus who present with digital ischemia and to understand the workup and treatment of the disease. Catastrophic antiphospholipid syndrome is a life-threatening variant of antiphospholipid syndrome (APS), and it is distinguished on the APS spectrum by its increased intensity and extent of thrombotic outcomes. Less than 1% of patients with APS develop CAPS and the demographic of patients affected are primarily females, 37 ± 14 years old, and have underlying primary APS or systemic lupus erythematosus (SLE). This is the case of a young female with lupus and end-stage renal disease secondary to lupus nephritis who presented to the emergency department for shortness of breath and bilateral leg swelling that eventually progressed to catastrophic antiphospholipid syndrome. She developed pulmonary embolisms, axillary hematoma, and bilateral lower extremity digital gangrene. The treatment course consisted of anticoagulation, steroids, intravenous immunoglobulin (IVIG), above-knee amputation, and eventually rituximab. Diagnosis and treatment of digital ischemia can be complex, especially, in the setting of lupus where the differential diagnosis is broad. A high index of suspicion for CAPS is essential for early diagnosis and treatment.

Hematological manifestations of antiphospholipid syndrome: Going beyond thrombosis

Thrombotic complications are a hallmark of antiphospholipid syndrome (APS). These vascular - arterial, venous, and/or small vessel - complications are well described and known to hematologists and healthcare providers caring for patients with this disease. In this review, we shed light on other hematological manifestations of the disease, including bleeding, thrombocytopenia, autoimmune hemolytic anemia, and thrombotic microangiopathy syndromes. While these manifestations are not bona fide clinical criteria for the diagnosis of APS, they frequently interact and contribute to the complexity of clinical management of APS.

Differential Diagnosis of Hyperferritinemia in Critically Ill Patients

BACKGROUND

Elevated serum ferritin is a common condition in critically ill patients. It is well known that hyperferritinemia constitutes a good biomarker for hemophagocytic lymphohistiocytosis (HLH) in critically ill patients. However, further differential diagnoses of hyperferritinemia in adult critically ill patients remain poorly investigated. We sought to systematically investigate hyperferritinemia in adult critically ill patients without HLH.

METHODS

In this secondary analysis of a retrospective observational study, patients ≥18 years admitted to at least one adult intensive care unit at Charité-Universitätsmedizin Berlin between January 2006 and August 2018, and with hyperferritinemia of ≥500 μg/L were included. Patients with HLH were excluded. All patients were categorized into non-sepsis, sepsis, and septic shock. They were also classified into 17 disease groups, based on their ICD-10 codes, and pre-existing immunosuppression was determined. Uni- and multivariable linear regression analyses were performed in all patients.

RESULTS

A total of 2583 patients were analyzed. Multivariable linear regression analysis revealed positive associations of maximum SOFA score, sepsis or septic shock, liver disease (except hepatitis), and hematological malignancy with maximum ferritin. T/NK cell lymphoma, acute myeloblastic leukemia, Kaposi's sarcoma, acute or subacute liver failure, and hepatic veno-occlusive disease were positively associated with maximum ferritin in post-hoc multivariable linear regression analysis.

CONCLUSIONS

Sepsis or septic shock, liver disease (except hepatitis) and hematological malignancy are important differential diagnoses in hyperferritinemic adult critically ill patients without HLH. Together with HLH, they complete the quartet of important differential diagnoses of hyperferritinemia in adult critically ill patients. As these conditions are also related to HLH, it is important to apply HLH-2004 criteria for exclusion of HLH in hyperferritinemic patients. Hyperferritinemic critically ill patients without HLH require quick investigation of differential diagnoses.

Extreme Hyperferritinemia: Causes and Prognosis

The significance of extreme hyperferritinemia and its association with certain diagnoses and prognoses are not well characterized. We performed a retrospective analysis of adult patients with at least one total serum ferritin (TSF) measurement ≥ 5000 µg/L over 2 years, in three university hospitals. Conditions associated with hyperferritinemia were collected, and patients were classified into 10 etiological groups. Intensive care unit (ICU) transfer and mortality rates were recorded. A total of 495 patients were identified, of which 56% had a TSF level between 5000 and 10,000 µg/L. There were multiple underlying causes in 81% of the patients. The most common causes were infections (38%), hemophagocytic lymphohistiocytosis (HLH, 18%), and acute hepatitis (14%). For TSF levels > 10,000 µg/L, there were no solid cancer or hematological malignancy without another cause of hyperferritinemia. Isolated iron-overload syndromes never exceeded TSF levels > 15,000 µg/L. Extreme hyperferritinemia (TSF levels > 25,000 µg/L) was associated with only four causes: HLH, infections, acute hepatitis and cytokine release syndromes. A total of 32% of patients were transferred to an ICU, and 28% died. Both ICU transfer rate and mortality were statistically associated with ferritin levels. An optimized threshold of 13,405 μg/L was the best predictor for the diagnosis of HLH, with a sensitivity of 76.4% and a specificity of 79.3%. Hyperferritinemia reflects a variety of conditions, but only four causes are associated with extreme hyperferritinemia, in which HLH and acute hepatitis are the most common. Extreme hyperferritinemia has a poor prognosis with increased mortality.

Expanding the spectrum of the hyperferritinemic syndrome, from pathogenic mechanisms to clinical observations, and therapeutic implications

From the introduction of hyperferritinemic syndrome concept, a growing body of evidence has suggested the role of ferritin as a pathogenic mediator and a relevant clinical feature in the management of patients with inflammatory diseases. From a pathogenic point of view, ferritin may directly stimulate the aberrant immune response by triggering the production of pro-inflammatory mediators in inducing a vicious pathogenic loop and contributing to the occurrence of cytokine storm syndrome. The latter has been recently defined as a clinical picture characterised by elevated circulating cytokine levels, acute systemic inflammatory symptoms, and secondary organ dysfunction beyond that which could be attributed to a normal response to a pathogen It is noteworthy that the occurrence of hyperferritinemia may be correlated with the development of the cytokine storm syndrome in the context of an inflammatory disease. In addition to adult onset Still's disease, macrophage activation syndrome, catastrophic anti-phospholipids syndrome, and septic shock, recent evidence has suggested this association between ferritin and life-threatening evolution in patients with systemic lupus erythematosus, with anti-MDA5 antibodies in the context of poly-dermatomyositis, with severe COVID-19, and with multisystem inflammatory syndrome. The possible underlying common inflammatory mechanisms, associated with hyperferritinemia, may led to the similar clinical picture observed in these patients. Furthermore, similar therapeutic strategies could be suggested inhibiting pro-inflammatory cytokines and improving long-term outcomes in these disorders. Thus, it could be possible to expand the spectrum of the hyperferritinemic syndrome to those diseases burdened by a dreadful clinical picture correlated with hyperferritinemia and the occurrence of the cytokine storm syndrome. In addition, the assessment of ferritin may provide useful information to the physicians in clinical practice to manage these patients. Therefore, ferritin may be considered a relevant clinical feature to be used as biomarker in dissecting the unmet needs in the management of these disorders. Novel evidence may thus support an expansion of the spectrum of the hyperferritinemic syndrome to these diseases burdened by a life-threatening clinical picture correlated with hyperferritinemia and the occurrence of the cytokine storm syndrome.

Ferritin - from iron, through inflammation and autoimmunity, to COVID-19

While it took decades to arrive to a conclusion that ferritin is more than an indicator of iron storage level, it took a short period of time through the COVID-19 pandemic to wonder what the reason behind high levels of ferritin in patients with severe COVID-19 might be. Unsurprisingly, acute phase reactant was not a satisfactory explanation. Moreover, the behavior of ferritin in patients with severe COVID-19 and the subsequent high mortality rates in patients with high ferritin levels necessitated further investigations to understand the role of ferritin in the diseases. Ferritin was initially described to accompany various acute infections, both viral and bacterial, indicating an acute response to inflammation. However, with the introduction of the hyperferritinemic syndrome connecting four severe pathological conditions such as adult-onset Still's disease, macrophage activation syndrome, catastrophic antiphospholipid syndrome, and septic shock added another aspect of ferritin where it could have a pathogenetic role rather than an extremely elevated protein only. In fact, suggesting that COVID-19 is a new member in the spectrum of hyperferritinemic syndrome besides the four mentioned conditions could hopefully direct further search on the pathogenetic role of ferritin. Doubtlessly, improving our understanding of those aspects of ferritin would enormously contribute to better coping with severe diseases in terms of treatment and prevention of complications. The origin, history, importance, and the advances of searching the role of ferritin in various pathological and clinical processes are presented hereby in our article. In addition, the implications of ferritin in COVID-19 are addressed.

Salivary Ferritin Changes in Patients with COVID-19

High ferritin serum levels can be found in patients with macrophage activation syndrome, and increased serum ferritin due to cytokine storm have been reported in severe COVID-19 patients. Saliva is being increasingly used in COVID-19 tests as a diagnostic sample for virus detection and quantification. This study aimed to evaluate the possible changes in ferritin in saliva in COVID-19 patients. In addition, the effects of different inactivation SARS-CoV-2 treatments in ferritin measurements in saliva, the correlation between ferritin in saliva and serum, and the possible effects of correction of ferritin values by total protein were assessed. Ferritin was measured in saliva from healthy (n = 30) and COVID-19 (n = 65) patients with severe, (n = 18) or mild (n = 47) disease, depending on the need for nasal flow oxygen or assisted respiration. Ferritin was also measured in paired serum and saliva samples (n = 32) from healthy and COVID-19 patients. The evaluated inactivation protocols did not affect the assay's results except the addition of 0.5% SDS. Significantly higher ferritin was found in the saliva of COVID-19 patients (median; 25-75th percentile) (27.75; 9.77-52.2 µg/L), compared with healthy controls (4.21; 2.6-8.08 µg/L). Individuals with severe COVID-19 showed higher ferritin values in saliva (48.7; 18.7-53.9) than mild ones (15.5; 5.28-41.3 µg/L). Significant correlation (r = 0.425; p < 0.001) was found between serum and saliva in ferritin. Ferritin levels were higher in COVID-19 patients in serum and saliva, and the highest values were found in those patients presenting severe symptomatology. In conclusion, ferritin in saliva has the potential to be a biomarker to evaluate severity in patients with COVID-19.

[Relationship between marked hyperferritinemia and hemophagocytic lymphohistiocytosis]

OBJECTIVE

To investigate the relationship between marked hyperferritinemia (MHF) and hemophagocytic lymphohistiocytosis(HLH).

METHODS

The clinical data of 123 patients with MHF admitted to Peking University People's Hospital from January 2017 to September 2018 were collected, including demographics, baseline characteristics, signs and symptoms, blood routine, blood biochemistry, coagulation function parameters, such as prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (Fib), d-dimer (D-D), fibrin degradation product (FDP), blood ferritin, natural killer (NK) cell activity, soluble interleukin (IL)-2 receptor and bone marrow examination. According to the diagnosis of HLH, the patients were divided into HLH group and non HLH group. The patients were divided into death group and survival group according to the 3-month follow-up results. The groups were compared and statistically analyzed.

RESULTS

In the 123 patients with MHF, the average age was (44.2±17.4) years with a male/female ratio of 1.3 ∶1. The most common causes were hematolo-gic malignancies, rheumatologic and inflammatory disorders, iron overload, and HLH. HLH was enriched as the ferritin increased, and the HLH ratios were 28.8%, 40.0%, 54.5%, 50.0%, 50.0% in ferritin value of 10 000-19 999, 20 000-29 999, 30 000-39 999, 40 000-49 999 μg/L, more than 50 000 μg/L respectively. There were 46 cases of HLH, among which 15 cases were secondary to malignancies, 14 cases secondary to rheumatologic disorders, 2 cases secondary to infection, and 15 cases with no clear precipitating cause. There were significant differences between the HLH group and non-HLH group in hepatomegaly, splenomegaly, lymphadenectasis, albumin (ALB), fibrinogen(Fib), P < 0.05, and no significant differences in age, gender, fever, disturbance of consciousness, ferritin level on presentation, maximum ferritin level, cytopenia in 2 or more cell lines, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), direct bilirubin (DBIL), triglyceride (TG), coagulation parameters (PT, APTT, D-D, FDP, exception of Fib), and mortality rate (P > 0.05). There were significant differences between the death group and survival group in disturbance of consciousness, platelet count, PT, TBIL, and DBIL (P < 0.05), but no significant differences in age, gender, fever, hepatomegaly, splenomegaly, lymphadenectasis, ferritin level on presentation, maximum ferritin level, neutrophils, hemoglobin, ALT, AST, ALB, TG, coagulation parameters (Fib, APTT, D-D, FDP, exception of PT) and the HLH ratio (P > 0.05).

CONCLUSION

HLH was enriched as the ferritin increased, but marked hyperferritinemia was not specific for HLH in adults.

[Therapeutic Options for the Management of Severe COVID-19: A Rheumatology Perspective]

The novel SARS-CoV-2 human coronavirus in Wuhan, China, has triggered a worldwide respiratory disease outbreak (COVID-19). Acute respiratory distress syndrome, multiorgan dysfunction and thrombotic events are among the leading causes of death in critically ill patients with COVID-19. The elevated inflammatory cytokines suggest that a "cytokine storm", also known as cytokine release syndrome, may play a major role in the pathology of COVID-19. In addition to anti-viral therapy and supportive treatment in critically ill patients, unique medications for this condition are also under investigation. Here we reviewed therapeutic options, including the antibody therapy that might be an immediate strategy for SARS-CoV-2 therapy.

Therapeutic options for the management of severe COVID-19: A rheumatology perspective

The novel SARS-CoV-2 human coronavirus in Wuhan, China, has triggered a worldwide respiratory disease outbreak (COVID-19). Acute respiratory distress syndrome (ARDS), multiorgan dysfunction and thrombotic events are among the leading causes of death in critically ill patients with COVID-19. The elevated inflammatory cytokines suggest that a "cytokine storm", also known as cytokine release syndrome (CRS), may play a major role in the pathology of COVID-19. In addition to anti-viral therapy and supportive treatment in critically ill patients, unique medications for this condition are also under investigation. Here we reviewed therapeutic options, including the antibody therapy that might be an immediate strategy for SARS-CoV-2 therapy.

Macrophage activation syndrome in COVID-19

The novel coronavirus epidemic is characterized by high rates of morbidity and relatively high mortality. Laboratory test results in patients include leukopenia, an increase in liver function tests and ferritin levels reaching hundreds, and sometimes thousands of units. These data remind us about the macrophage activation syndrome (MAC). Secondary hemophagocytic lymphohistiocytosis syndrome, MAC, which pathogenesis is based on a defect in the mechanisms of T-cell cytotoxicity and decreased level of natural killer cells associated with the defect in the perforin-encoding gene as well as hyperproduction of a number of cytokines – interleukin (IL)-1â, tumor necrosis factor-á, etc. by T-lymphocytes and histiocytes, indirectly leading to the activation of macrophages and production of proinflammatory cytokines, in particular IL-6 hyperproduction. MAC is one of "hyperferritinemic syndromes". These disorders have similar clinical and laboratory manifestations, and they also respond to similar treatments, suggesting that hyperferritinemia may be involved in the overall pathogenesis and is characterized by elevated ferritin level and cytokine storm. Despite the fact that data on the immune and inflammatory status in patients with COVID-19 have only started to appear, it is already clear that hyperinflammation and coagulopathy affect the disease severity and increase the risk of death in patients infected with SARS-CoV-2. Hence, understanding the pathogenesis of the novel coronavirus infection can help in its early diagnostics and treatment.

Ferritin, fever, and frequent visits: Hyperferritinemic syndromes in the emergency department

Fever of unknown origin (FUO) is defined as persistent fevers without an identifiable cause despite extensive medical workup. Emergency physicians caring for patients reporting a persistent, nonspecific, febrile illness should carefully consider potentially serious non-infectious causes of FUO. We present a case of a 35-year-old man who presented to the emergency department (ED) three times over a 10-day period for persistent febrile illness and was ultimately diagnosed with Adult-Onset Still's Disease (AOSD) after a serum ferritin level was found to be over 42,000 μg/L. AOSD, along with macrophage activation syndrome, catastrophic antiphospholipid syndrome, and septic shock comprise the four hyperferritinemic syndromes. These are potentially life-threatening febrile illnesses that characteristically present with elevated ferritin levels. In this article, we highlight the value of a serum ferritin level in the workup of a patient with prolonged febrile illness and its utility in facilitating early diagnosis and prompt treatment of hyperferritinemic syndromes in the ED.

Clinical and prognostic significance of elevated ferritin levels in hospitalised adults

PURPOSE OF THE STUDY

Elevated ferritin levels are associated with a variety of infectious, malignant and inflammatory diseases. We aimed to investigate the prognostic value of markedly elevated ferritin levels in hospitalised patients with various medical conditions.

STUDY DESIGN

Retrospective analysis of patients with a ferritin level higher than 2000 ng/mL hospitalised in Sheba Medical Center between 1 January 2007 and 31 December 2015. Medical conditions of these patients were recorded. In-hospital, 30-day and 1-year mortality rates were evaluated according to ferritin ranges and clinical categories.

RESULTS

The study included 722 patients (63.4% men) with a mean age of 63.9±16.7 years. The most common clinical conditions associated with markedly elevated ferritin were infectious diseases and malignancies. The highest mean ferritin levels were associated with rheumatological/inflammatory conditions (16 241.3 ng/dL), particularly in patients with macrophage activation syndrome (MAS) (96 615.5 ng/dL). In-hospital, 30-day and 1-year mortality rates were 32.3%, 46.7% and 70.8%, respectively. The highest in-hospital, 30-day and 1-year mortality rates were observed among patients with solid malignancies (40.1%, 64.7% and 90.3%, respectively), whereas the lowest rates were found among patients with rheumatological/inflammatory conditions, including MAS (21.4%, 38.1% and 45.2%, respectively). Ferritin levels were not associated with mortality.

CONCLUSIONS

In hospitalised patients, ferritin levels higher than 2000 ng/mL are mainly associated with infectious and malignant diseases but do not predict mortality.

SARS-CoV-2 and inflammatory responses: From mechanisms to the potential therapeutic use of intravenous immunoglobulin

A novel coronavirus (SARS-CoV-2) is responsible for a severe acute respiratory syndrome called coronavirus disease 2019 (COVID-19). It is originated in Wuhan, China, in December 2019. Due to its extreme transmissibility with droplets and human contacts, in a few months, it has become a pandemic. Nowadays, no effective therapy is available, and the scientific community is moving to find a therapeutic choice to fight this silent enemy. Studies are ongoing on several therapeutic options, including antiviral agents, immunomodulant drugs, and immunotherapy. Due to viral features, including the ability to start an inflammatory response that seems to be the fulcrum of COVID-19 pathogenic action, immunotherapy could represent a promising alternative waiting for the vaccine. High-dose intravenous immunoglobulin (IVIg), already used in other infectious diseases, could represent an effective help. The aim of this narrative review is to reassemble the clinical experiences on the use of IVIg in COVID-19 and the rationale of its use.

Anti-phospholipid syndrome and COVID-19 thrombosis: connecting the dots

As the coronavirus disease 2019 (COVID-19) pandemic, which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is spreading rapidly worldwide, it has emerged as a leading cause of mortality, resulting in >1 million deaths over the past 10 months. The pathophysiology of COVID-19 remains unclear, posing a great challenge to the medical management of patients. Recent studies have reported an unusually high prevalence of thromboembolic events in COVID-19 patients, although the mechanism remains elusive. Several studies have reported the presence of aPLs in COVID-19 patients. We have noticed similarities between COVID-19 and APS, which is an autoimmune prothrombotic disease that is often associated with an infective aetiology. Molecular mimicry and endothelial dysfunction could plausibly explain the mechanism of thrombogenesis in acquired APS. In this review, we discuss the clinicopathological similarities between COVID-19 and APS, and the potential role of therapeutic targets based on the anti-phospholipid model for COVID-19 disease.

Assessment of serum ferritin as a biomarker in COVID-19: bystander or participant? Insights by comparison with other infectious and non-infectious diseases

BACKGROUND

The 2019 coronavirus disease (COVID-19) caused by the SARS-CoV-2 virus has an impact on all aspects of patient care. Serum ferritin generally represents a biomarker of choice when iron deficiency is suspected. However, ferritin is also an acute-phase-protein exhibiting elevated serum concentration in various inflammatory diseases. Here we focus on the role of serum ferritin for diagnostic and clinical management of patients with COVID-19 in comparison with other infectious and non-infectious diseases.

METHODS

We examined scientific articles listed in PubMed reporting on ferritin in various infectious and non-infectious diseases. We then compared these results with nine current COVID-19 ferritin reports published in 2020.

RESULTS

Several non-infectious, as well as non-COVID-19 infectious diseases, are characterised by a partly dramatic elevation of serum ferritin levels. All COVID-19 studies published between February and May 2020, which documented laboratory serum ferritin, indicate ferritin as a biomarker of COVID-19 severity in hospitalised patients.

CONCLUSIONS

Serum ferritin may be considered both a prognostic and stratifying biomarker that can also contribute to therapeutic decision-making concerning patients with COVID-19. It should be emphasised, however, that most scientific reports refer to cohorts in the Asian region. Further validation in other cohorts is urgently required.

Ferritin, Erythrocyte Sedimentation Rate, and C-Reactive Protein Level in Patients with Chikungunya-Induced Chronic Polyarthritis

Chikungunya virus (CHIKV) is a global emergent arthritogenic alphavirus transmitted by anthropophilic Stegomyia mosquitoes. Chikungunya fever may evolve to chronic arthralgia in 57-80% of infected patients. This study was developed to identify possibly fast, simple low-cost biomarkers to monitor chronic CHIKV-induced articular disease. Between 2017 and 2018, we analyzed clinical data of patients meeting the criteria established by standard protocols to define chronic chikungunya articular disease. Patients were classified according to the disease activity scores, inflammatory biomarkers (erythrocyte sedimentation rate [ESR], ferritin, and C-reactive protein [CRP] serum), positive rheumatoid factor, comorbidities, smoking, and previous use of corticosteroids determined before beginning therapy. Of 106 patients, 98 (92.5%) were women with mean age of 52 ± 13 years, 6.8 ± 4.4 months of illness duration at the first medical appointment, and 6.7 ± 4.5 affected joints. Mean ESR (26 ± 19), CRP (2.6 ± 3.6), and stratified ferritin (144 ± 115) levels were normal according to reference values. There was no significance in comparing the levels of inflammatory biomarkers and the additional variables analyzed in the presence of moderate chronic joint disease in the study population. However, we identified a negative correlation between disease activity measures and duration of disease at the first medical evaluation after initial infection (P < 0.001), corroborating data observed in the literature.

COVID-19 as part of the hyperferritinemic syndromes: the role of iron depletion therapy

SARS-CoV-2 infection is characterized by a protean clinical picture that can range from asymptomatic patients to life-threatening conditions. Severe COVID-19 patients often display a severe pulmonary involvement and develop neutrophilia, lymphopenia, and strikingly elevated levels of IL-6. There is an over-exuberant cytokine release with hyperferritinemia leading to the idea that COVID-19 is part of the hyperferritinemic syndrome spectrum. Indeed, very high levels of ferritin can occur in other diseases including hemophagocytic lymphohistiocytosis, macrophage activation syndrome, adult-onset Still's disease, catastrophic antiphospholipid syndrome and septic shock. Numerous studies have demonstrated the immunomodulatory effects of ferritin and its association with mortality and sustained inflammatory process. High levels of free iron are harmful in tissues, especially through the redox damage that can lead to fibrosis. Iron chelation represents a pillar in the treatment of iron overload. In addition, it was proven to have an anti-viral and anti-fibrotic activity. Herein, we analyse the pathogenic role of ferritin and iron during SARS-CoV-2 infection and propose iron depletion therapy as a novel therapeutic approach in the COVID-19 pandemic.

Pro-inflammatory properties of H-ferritin on human macrophages, ex vivo and in vitro observations

Ferritin is an iron-binding molecule, which comprises 24 subunits, heavy (FeH) and light (FeL) subunits, suggested to have a pathogenic role by the 'hyperferritinemic syndrome'. In this work, we tested (1) FeH and FeL in bone marrow (BM) and sera in patients with macrophage activation syndrome (MAS); (2) pro-inflammatory effects of ferritin, FeL, and FeH on macrophages; (3) ability of FeH-stimulated macrophages to stimulate the proliferation of peripheral blood mononuclear cells (PBMCs); (4) production of mature IL-1β and IL-12p70 in extracellular compartments of FeH-stimulated macrophages. Immunofluorescence analysis and liquid chromatography mass spectrometry (LC-MS/MS) based proteomics were performed to identify FeL and FeH in BM and sera, respectively, in the same patients. Macrophages were stimulated with ferritin, FeH, and FeL to assess pro-inflammatory effects by RT-PCR and western blot. The proliferation of co-cultured PBMCs with FeH-stimulated macrophages was tested. Immunofluorescence showed an increased FeH expression in BMs, whereas LC-MS/MS identified that FeL was mainly represented in sera. FeH induced a significant increase of gene expressions of IL-1β, IL-6, IL-12, and TNF-α, more marked with FeH, which also stimulated NLRP3. FeH-stimulated macrophages enhanced the proliferation of PBMCs. The ELISA assays showed that mature form of IL-1β and IL-12p70 were increased, in extracellular compartments of FeH-stimulated macrophages. Our results showed FeH in BM biopsies of MAS patients, whereas, LC-MS/MS identified FeL in the sera. FeH showed pro-inflammatory effects on macrophages, stimulated NLRP3, and increased PBMCs proliferation.

Immunomodulatory therapy for the management of severe COVID-19. Beyond the anti-viral therapy: A comprehensive review

Severe Acute Respiratory Syndrome related to Coronavirus-2 (SARS-CoV-2), coronavirus disease-2019 (COVID-19) may cause severe illness in 20% of patients. This may be in part due to an uncontrolled immune-response to SARS-CoV-2 infection triggering a systemic hyperinflammatory response, the so-called "cytokine storm". The reduction of this inflammatory immune-response could be considered as a potential therapeutic target against severe COVID-19. The relationship between inflammation and clot activation must also be considered. Furthermore, we must keep in mind that currently, no specific antiviral treatment is available for SARS-CoV-2. While moderate-severe forms need in-hospital surveillance plus antivirals and/or hydroxychloroquine; in severe and life-threating subsets a high intensity anti-inflammatory and immunomodulatory therapy could be a therapeutic option. However, right data on the effectiveness of different immunomodulating drugs are scarce. Herein, we discuss the pathogenesis and the possible role played by drugs such as: antimalarials, anti-IL6, anti-IL-1, calcineurin and JAK inhibitors, corticosteroids, immunoglobulins, heparins, angiotensin-converting enzyme agonists and statins in severe COVID-19.

Severe COVID-19, Another Piece in the Puzzle of the Hyperferritinemic Syndrome. An Immunomodulatory Perspective to Alleviate the Storm

The coronavirus disease 2019 (COVID-19), an acute respiratory disease caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), has been declared as a worldwide public health emergency. Interestingly, severe COVID-19 is characterized by fever, hyperferritinemia, and a hyper-inflammatory process with a massive release of pro-inflammatory cytokines, which may be responsible for the high rate of mortality. These findings may advocate for a similarity between severe COVID-19 and some challenging rheumatic diseases, such as adult onset Still's disease, secondary hemophagocytic lymphohistiocytosis, and catastrophic anti-phospholipid syndrome, which have been included in the “hyperferritinemic syndrome” category. Furthermore, as performed in these hyper-inflammatory states, severe COVID-19 may benefit from immunomodulatory therapies.

Hyperferritinaemia: An Iron Sword of Autoimmunity

BACKGROUND

Ferritin is a molecule that plays many roles being the storage for iron, signalling molecule, and modulator of the immune response.

METHODS

Different electronic databases were searched in a non-systematic way to find out the literature of interest.

RESULTS

The level of ferritin rises in many inflammatory conditions including autoimmune disorders. However, in four inflammatory diseases (i.e., adult-onset Still's diseases, macrophage activation syndrome, catastrophic antiphospholipid syndrome, and sepsis), high levels of ferritin are observed suggesting it as a remarkable biomarker and pathological involvement in these diseases. Acting as an acute phase reactant, ferritin is also involved in the cytokine-associated modulator of the immune response as well as a regulator of cytokine synthesis and release which are responsible for the inflammatory storm.

CONCLUSION

This review article presents updated information on the role of ferritin in inflammatory and autoimmune diseases with an emphasis on hyperferritinaemic syndrome.

Evaluation of macrophage activation syndrome in hospitalised patients with Kikuchi-Fujimoto disease based on the 2016 EULAR/ACR/PRINTO classification criteria

BACKGROUND

To evaluate the impact of macrophage activation syndrome (MAS) on clinical features in patients with Kikuchi-Fujimoto disease (KFD) and to compare the features of MAS in KFD with those of adult-onset Still's disease (AOSD) and systemic lupus erythematosus (SLE).

METHODS

The medical records of febrile patients hospitalised with KFD between November 2005 and April 2017 were reviewed. Patients fulfilling the 2016 classification criteria for MAS were classified as having MAS. Clinical and laboratory features of patients with KFD with and without MAS were evaluated. Poor hospitalisation outcomes were defined as intensive care unit admission or in-hospital mortality. The treatment outcomes of MAS in KFD, AOSD, and SLE were also compared.

RESULTS

Among 78 patients hospitalised with KFD, 24 (30.8%) patients had MAS during admission. Patients with KFD and MAS more frequently required glucocorticoid treatment (66.7% vs 40.7%, p = 0.036) and had longer hospital stays than patients with KFD without MAS (12.5 vs 8.5 days, p<0.001). In addition, patients with MAS had worse hospitalisation outcomes than patients without MAS (29.2% vs. 0.0%, p<0.001). Among patients with MAS in KFD, AOSD, and SLE, the number of patients requiring glucocorticoid treatment after 3 months was significantly lower among patients with MAS and KFD (KFD 33.3%, AOSD 88.9%, SLE 100%, p<0.001).

CONCLUSIONS

The presence of MAS in KFD was associated with adverse clinical outcomes including higher steroid usage and worse hospitalisation outcomes. However, compared to those with AOSD and SLE, patients with MAS and KFD were less likely to require long-term glucocorticoid treatment.

The treatment of anti-phospholipid syndrome: A comprehensive clinical approach

Anti-phospholipid syndrome (APS) is an acquired pro-thrombotic autoimmune disease that predisposes to thrombotic events and/or obstetric complications, in the persistent presence of anti-phospholipid antibodies (aPL). Life long moderate-intensity anticoagulation is the option of choice for aPL-positive patients with a previous thrombosis; critical issues concern the management of those with a history of arterial event due to the high rate of recurrence. Alternatives comprise anti-platelet agents and high-intensity anticoagulation. Low dose aspirin (LDASA) and low molecular weight heparin provide the mainstay of the treatment of obstetric APS, allowing a birth rate in 70% of cases. The management of refractory APS, thrombotic as well as obstetric, is highly debated, but an increasing burden of evidence points towards the beneficial effects of multiple treatments. Similarly, a management envisaging multiple drugs (anticoagulation, steroids, plasma exchange and/or intravenous immunoglobulins) is the most effective approach in catastrophic APS. Asymptomatic aPL carriers are at higher risk of thrombotic and obstetric complications compared to the general population, thus potentially benefitting of a pharmacological intervention. LDASA and hydroxychloroquine can be considered as options, in particular in case of high risk aPL profile, concomitant cardiovascular risk factors or associated autoimmune disease. APS is apparently a simple condition, but its multifaceted nature requires a complex and tailored treatment.

Immunological Tolerance, Pregnancy, and Preeclampsia: The Roles of Semen Microbes and the Father

Although it is widely considered, in many cases, to involve two separable stages (poor placentation followed by oxidative stress/inflammation), the precise originating causes of preeclampsia (PE) remain elusive. We have previously brought together some of the considerable evidence that a (dormant) microbial component is commonly a significant part of its etiology. However, apart from recognizing, consistent with this view, that the many inflammatory markers of PE are also increased in infection, we had little to say about immunity, whether innate or adaptive. In addition, we focused on the gut, oral and female urinary tract microbiomes as the main sources of the infection. We here marshall further evidence for an infectious component in PE, focusing on the immunological tolerance characteristic of pregnancy, and the well-established fact that increased exposure to the father's semen assists this immunological tolerance. As well as these benefits, however, semen is not sterile, microbial tolerance mechanisms may exist, and we also review the evidence that semen may be responsible for inoculating the developing conceptus (and maybe the placenta) with microbes, not all of which are benign. It is suggested that when they are not, this may be a significant cause of PE. A variety of epidemiological and other evidence is entirely consistent with this, not least correlations between semen infection, infertility and PE. Our view also leads to a series of other, testable predictions. Overall, we argue for a significant paternal role in the development of PE through microbial infection of the mother via insemination.

Diagnosis of hyperferritinemia in routine clinical practice

The discovery of hyperferritinemia is often fortuitous, revealed in results from a laboratory screening or follow-up test. The aim of the diagnostic procedure is therefore to identify its cause and to identify or rule out hepatic iron overload, in a three-stage process. In the first step, clinical findings and several simple laboratory tests are sufficient to detect four of the most frequent causes of high ferritin concentrations: alcoholism, inflammatory syndrome, cytolysis, and metabolic syndrome. None of these causes is associated with substantial hepatic iron overload. If transferrin saturation is high (> 50%), hereditary hemochromatosis will be considered in priority. In the second phase, rarer diseases will be sought. Among them, only chronic hematologic diseases (acquired or congenital) and excessive iron intake or infusions (patients on chronic dialysis and high-level athletes) are at risk of iron overload. In the third stage, if a doubt persists about the cause or if the ferritin concentration is very high or continues to rise, it is essential to verify the hepatic iron concentration to rule out overload. The principal examination to guide diagnosis and treatment is hepatic MRI to assess its iron concentration. It is essential to remember that more than 40% of patients with hyperferritinemia have several causes simultaneously present.

Treatment of catastrophic antiphospholipid syndrome

PURPOSE OF REVIEW

Catastrophic antiphospholipid syndrome (CAPS) is a severe manifestation of antiphospholipid syndrome (APS). Although affecting only 1% of patients with APS, the condition is frequently fatal if not recognized and treated early. Here, we will review the current approach to diagnosis and treatment of CAPS.

RECENT FINDINGS

Data from the international 'CAPS registry', spearheaded by the European Forum on Antiphospholipid Antibodies, have improved our understanding of at-risk patients, typical clinical features, and precipitating diagnoses. Current guidelines also continue to support the role of anticoagulants and glucocorticoids as foundation therapy in all patients. Finally, new basic science and case series suggest that novel therapies, such as rituximab and eculizumab, warrant further study.

SUMMARY

Attention to associated diagnoses, such as infection and systemic lupus erythematosus (SLE), is critical at the time of diagnosis. All patients should be treated with anticoagulants, corticosteroids, and possibly plasma exchange. In patients with SLE, cyclophosphamide should be considered. In refractory or relapsing cases, new therapies, such as rituximab and possibly eculizumab, may be options, but need further study.

Plasma Exchange in the Management of Catastrophic Antiphospholipid Syndrome

Objective. Report of a case of catastrophic antiphospholipid syndrome (CAPS) with multiple organ involvement leading to a life-threatening condition despite early combination corticosteroid and heparin therapy. Initiation of plasma exchange led to rapid improvement of the patient's general condition. Design. Case report. Setting. University teaching hospital medical intensive care unit. Patient. Single case: 52-year-old man hospitalized for catastrophic antiphospholipid syndrome (CAPS) with cardiac, renal, and cutaneous involvement. Despite early methylprednisolone and heparin therapy, the patient's condition progressively deteriorated, resulting in acute renal failure, right adrenal hemorrhage, and pulmonary involvement, leading to acute respiratory distress on day 6, requiring high-flow nasal cannula oxygen therapy with FiO₂ of 1.0. Interventions. Plasma exchange was started on day 6. Endpoints and Main Results. A marked improvement of the patient's general condition was observed after initiation of plasma exchange, with successful weaning of oxygen therapy and normalization of platelet count, troponin, and serum creatinine within four days. Conclusions. This case illustrates the efficacy of plasma exchange in CAPS and the difficulty for physicians to determine the optimal timing of plasma exchange.

sCD163 in AOSD: a biomarker for macrophage activation related to hyperferritinemia

Ferritin has a key role in Adult-onset Still's disease (AOSD). Its production seems related to macrophage activation of which sCD163 is a major serum marker. Thus, we aimed at evaluating the role of sCD163 in AOSD and its relationship with ferritin. Furthermore, we determined the expression of CD163 and ferritin in a lymph-node from an AOSD patient. sCD163 and serum ferritin were measured in 34 patients with AOSD (21 active, 13 non-active), 18 sepsis and 22 healthy controls (HC). Immunohistology was performed on a lymph-node from an AOSD patient in order to detect CD163 and ferritin. A tonsil from an HC was used as control. Mean sCD163 (8.6 ± 5.4 mg/L) was higher in active AOSD than "non-active" patients (4.6 ± 2.7 mg/L, p = 0.02). The mean sCD163 in AOSD (6.9 ± 4.9 mg/L) and sepsis (7.1 ± 5.6 mg/L) were higher than in HC (2.56 ± 1.17 mg/L, p < 0.001), but no difference between AOSD and sepsis was detected. sCD163 positively correlated with ferritin (p = 0.0045; r = 0.4755) only in AOSD. Serum ferritin (mean 3,640.1 ± 6,896.9 µg/L) was higher in active AOSD than in sepsis (1,720.2 ± 3,882.1 µg/L, p < 0.007). CD163 was equally distributed in the B and T areas of both lymph-node and tonsil. Differently from the tonsil, ferritin was expressed only in the lymph-node B area. sCD163 is a marker of disease activity in AOSD. The correlation with ferritin may lead to hypothesize a macrophage activation related to hyperferritinemia. Ferritin was found expressed only in the B area of the AOSD lymph-node, suggesting a role for this molecule as an antigen in the disease pathogenesis.

Hyperferritinemic syndrome: Still's disease and catastrophic antiphospholipid syndrome triggered by fulminant Chikungunya infection: a case report of two patients

There are four medical conditions characterized by high levels of ferritin, the macrophage activation syndrome (MAS), adult onset Still' s disease (AOSD), catastrophic antiphospholipid syndrome (CAPS), and septic shock, that share similar clinical and laboratory features, suggesting a common pathogenic mechanism. This common syndrome entity is termed "the hyperferritinemic syndrome." Here, we describe two different cases of hyperferritinemic syndrome triggered by Chikungunya fever virus infection: a 21-year-old female with SLE and a 32-year-old male patient who developed AOSD after the coinfection of dengue and Chikungunya viruses.

The role of infectious diseases in the catastrophic antiphospholipid syndrome

Catastrophic antiphospholipid syndrome (CAPS), also called "Asherson syndrome", is a variant of the antiphospholipid syndrome (APS) that occurs in less than 1% of APS cases. The etiology of CAPS is uncertain; however, several triggering factors have been recognized. The most common of these are infectious diseases, particularly those of the respiratory tract. CAPS pathogenesis is incompletely understood, but several theories have been proposed, such as the molecular mimicry theory, which describes the production of anti-β2-glycoprotein I (GP1) antibody in response to infection. The process is complex and involves the activation of Toll-like receptor 4 (TLR-4), which triggers a cytokine storm, followed by endothelial alterations that induce a procoagulant state.

Evaluating the optimal serum ferritin level to identify hemophagocytic lymphohistiocytosis in the critical care setting

Ferritin is known to be involved in numerous physiological roles, such as iron storage, as well as various pathological conditions and in generalized inflammatory states. Hyperferritinemia is also encountered in the setting of hemophagocytic lymphohistiocytosis (HLH). Current diagnostic criteria exist to define HLH based on several clinical and biochemical markers, including the serum ferritin level. In this study, we retrospectively evaluated the value of ferritin >500 ng/mL in diagnosing HLH in 344 consecutive patients admitted to the medical intensive care unit at our hospital. Nine cases of HLH were identified. Comparison of the HLH with the non-HLH group showed that their maximum median serum ferritin level was 25,652 (range 1977-100,727 ng/mL) versus 1180 (503-85,168 ng/mL) (P < 0.001), platelets were 30 (5-92 × 10(3)/μL) versus 113 (0-507 × 10(3)/μL) (P < 0.001), absolute neutrophil counts were 2.56 (0.02-23.7 × 10(3)/μL) versus 7.7 (0.01-82.7 × 10(3)/μL) (P = 0.002), and triglycerides were 255 (156-394 mg/dL) versus 127 (17-624 mg/dL) (P = 0.002), respectively. Using a receiver operating characteristic curve, the optimal maximum serum ferritin level for the diagnosis of HLH was 3951 ng/mL, exceeding the current diagnostic cutoff set forth in the HLH-2004 guidelines. These data suggest that a higher cutoff value of ferritin level may have improved utility in the diagnosis of secondary HLH in the critical care setting.

Marked hyperferritinemia does not predict for HLH in the adult population

Hemophagocytic lymphohistiocytosis (HLH) is a rare syndrome of uncontrolled immune activation that has gained increasing attention during the last decade. The diagnosis of HLH is based on a constellation of clinical and laboratory abnormalities, including elevated serum ferritin levels. In the pediatric population, marked hyperferritinemia is specific for HLH. To determine what conditions are associated with profoundly elevated ferritin in the adult population, we performed a retrospective analysis in a large academic health care system. We identified 113 patients with serum ferritin levels higher than 50,000 µg/L. The most frequently observed conditions included renal failure, hepatocellular injury, infections, and hematologic malignancies. Our results suggest that marked hyperferritinemia can be seen in a variety of conditions and is not specific for HLH in adults.

Serum ferritin is an important inflammatory disease marker, as it is mainly a leakage product from damaged cells

"Serum ferritin" presents a paradox, as the iron storage protein ferritin is not synthesised in serum yet is to be found there. Serum ferritin is also a well known inflammatory marker, but it is unclear whether serum ferritin reflects or causes inflammation, or whether it is involved in an inflammatory cycle. We argue here that serum ferritin arises from damaged cells, and is thus a marker of cellular damage. The protein in serum ferritin is considered benign, but it has lost (i.e. dumped) most of its normal complement of iron which when unliganded is highly toxic. The facts that serum ferritin levels can correlate with both disease and with body iron stores are thus expected on simple chemical kinetic grounds. Serum ferritin levels also correlate with other phenotypic readouts such as erythrocyte morphology. Overall, this systems approach serves to explain a number of apparent paradoxes of serum ferritin, including (i) why it correlates with biomarkers of cell damage, (ii) why it correlates with biomarkers of hydroxyl radical formation (and oxidative stress) and (iii) therefore why it correlates with the presence and/or severity of numerous diseases. This leads to suggestions for how one might exploit the corollaries of the recognition that serum ferritin levels mainly represent a consequence of cell stress and damage.

Catastrophic antiphospholipid syndrome: task force report summary

The Task Force on Catastrophic Antiphospholipid Syndrome (CAPS) aimed to assess the current knowledge on pathogenesis, clinical and laboratory features, diagnosis and classification, precipitating factors and treatment of CAPS. This article summarizes the main aspects of its final report.

14th International Congress on Antiphospholipid Antibodies Task Force Report on Catastrophic Antiphospholipid Syndrome

The 'Task Force on Catastrophic Antiphospholipid Syndrome (CAPS)' was developed on the occasion of the 14th International Congress on Antiphospholipid Antibodies. The objectives of this Task Force were to assess the current knowledge on pathogenesis, clinical and laboratory features, diagnosis and classification, precipitating factors and treatment of this condition in order to address recommendations for future research. This article summarizes the studies analyzed by the Task Force, its recommendations and the future research agenda.

The hyperferritinemic syndrome: macrophage activation syndrome, Still's disease, septic shock and catastrophic antiphospholipid syndrome

BACKGROUND

Over the last few years, accumulating data have implicated a role for ferritin as a signaling molecule and direct mediator of the immune system. Hyperferritinemia is associated with a multitude of clinical conditions and with worse prognosis in critically ill patients.

DISCUSSION

There are four uncommon medical conditions characterized by high levels of ferritin, namely the macrophage activation syndrome (MAS), adult onset Still's disease (AOSD), catastrophic antiphospholipid syndrome (cAPS) and septic shock, that share a similar clinical and laboratory features, and also respond to similar treatments, suggesting a common pathogenic mechanism. Ferritin is known to be a pro-inflammatory mediator inducing expression of pro-inflammatory molecules, yet it has opposing actions as a pro-inflammatory and as an immunosuppressant. We propose that the exceptionally high ferritin levels observed in these uncommon clinical conditions are not just the product of the inflammation but rather may contribute to the development of a cytokine storm.

SUMMARY

Here we review and compare four clinical conditions and the role of ferritin as an immunomodulator. We would like to propose including these four conditions under a common syndrome entity termed "Hyperferritinemic Syndrome".