Discrimination of COVID-19 From Inflammation-Induced Cytokine Storm Syndromes Using Disease-Related Blood Biomarkers.

OBJECTIVE: Infection with the novel coronavirus SARS-CoV-2 triggers severe illness with high mortality in a subgroup of patients. Such a critical course of COVID-19 is thought to be associated with the development of cytokine storm, a condition seen in macrophage activation syndrome (MAS) and secondary hemophagocytic lymphohistiocytosis (HLH). However, specific data demonstrating a clear association of cytokine storm with severe COVID-19 are still lacking. The aim of this study was to directly address whether immune activation in COVID-19 does indeed mimic the conditions found in these classic cytokine storm syndromes. METHODS: Levels of 22 biomarkers were quantified in serum samples from patients with COVID-19 (n = 30 patients, n = 83 longitudinal samples in total), patients with secondary HLH/MAS (n = 50), and healthy controls (n = 9). Measurements were performed using bead array assays and single-marker enzyme-linked immunosorbent assay. Serum biomarker levels were assessed for correlations with disease outcome. RESULTS: In patients with secondary HLH/MAS, we observed pronounced activation of the interleukin-18 (IL-18)-interferon-γ axis, increased serum levels of IL-1 receptor antagonist, intercellular adhesion molecule 1, and IL-8, and strongly reduced levels of soluble Fas ligand in the course of SARS-CoV-2 infection. These observations appeared to discriminate immune dysregulation in critical COVID-19 from the well-recognized characteristics of other cytokine storm syndromes. CONCLUSION: Serum biomarker profiles clearly separate COVID-19 from MAS or secondary HLH in terms of distinguishing the severe systemic hyperinflammation that occurs following SARS-CoV-2 infection. These findings could be useful in determining the efficacy of drugs targeting key molecules and pathways specifically associated with systemic cytokine storm conditions in the treatment of COVID-19.

Biomarkers for Early Diagnosis of Hemophagocytic Lymphohistiocytosis in Critically Ill Patients.

Many biomarkers have been proposed for the diagnosis of secondary hemophagocytic lymphohistiocytosis (HLH) in adults, but comparative studies are lacking. We analyzed ferritin, glycosylated ferritin, soluble CD25, CD163 and CD14, IL-6, IFN-γ, IL-18, IL-10, IL-1ß, IL-12p70, IL-17α, IP-10, and CXCL9 levels to differentiate HLH from sepsis in critically ill patients. Of 120 patients, HLH was confirmed for 14 patients. Among the biomarkers tested, ferritin, IL-18, and glycosylated ferritin were the most efficient parameters for early diagnosis of HLH. With a sensitivity set at 85%, ferritin, IL-18, and glycosylated ferritin were the biomarkers with the highest specificity: 84, 79, and 71% respectively. Combining IL-18 with the HScore provided a new score with an increased specificity compared to the HScore alone, 86% compared to 70% with a sensitivity set at 100%. A distinct cytokine pattern was highlighted in patients with malignancy-triggered HLH, with highly increased levels of INF-É£ and CXCL9, compared to HLH secondary to infection. This is the largest study available to date, comparing diagnostic biomarkers for HLH on a cohort of critically ill adult patients. Serum ferritin was the most discriminating parameter for early diagnosis of secondary HLH. IL18*HScore was identified as a highly potential score.

Performances of the H-Score for Diagnosis of Hemophagocytic Lymphohistiocytosis in Adult and Pediatric Patients.

OBJECTIVES: In this study, we compared the performances of adapted hemophagocytic lymphohistiocytosis (HLH)-2004 guidelines with those of the new diagnostic H-score to identify patients with HLH in a multicenter cohort consisting of adult and pediatric cases of suspected HLH. METHODS: The study sample consisted of 147 cases, including 20 adults and 16 children with HLH. Two sets of biological data were evaluated: at presentation and the maximal values reached during the episode. RESULTS: At presentation, for both children and adults, the H-score was more efficient than adapted HLH-2004 guidelines to identify HLH. The diagnostic sensitivity and specificity were respectively 100% and 80% for children and 90% and 79% for adults. However, for adults, performances became comparable between adapted HLH-2004 guidelines and H-score as patient clinical status worsened. The specificity decreased to 73% for the same sensitivity. CONCLUSIONS: The adapted HLH-2004 guidelines seem less powerful and H-score seems to be more appropriate for children, which may be due to less significantly marked biological features. For adults, H-score performances are better when determined at presentation. The cutoff value of the H-score should be adapted depending on the target population to obtain optimal specificity.

Anti-GQ1b antibody syndrome presenting as acute isolated bilateral ophthalmoplegia: Report on two patients and review of the literature.

BACKGROUND: Miller Fisher syndrome (MFS) is an acute polyradiculoneuritis regarded as an uncommon clinical variant of Guillain-Barré syndrome (GBS). MFS is characterized by the acute onset of the clinical triad of ophthalmoplegia, cereballar ataxia and areflexia. Atypical forms of MFS presenting as isolated ophthalmoplegia without ataxia have been rarely described, mostly in adults. PATIENTS: We present two cases of acute isolated bilateral ophthalmoplegia in childhood, both occurring shortly after Campylobacter jejuni enteritis. Serum analysis of anti-ganglioside antibodies revealed elevated levels of anti-GQ1b IgG and IgM. We observed in both children complete spontaneous resolution several weeks after onset. CONCLUSION: The cases of the two patients confirm the rare but possible occurrence of atypical MFS in young children a few weeks after gastrointestinal infection. Identification of high levels of anti-GQ1b antibodies in the serum may help confirm the diagnosis of MFS even when its clinical presentation is incomplete.

Detection of Herpesviridae in whole blood by multiplex PCR DNA-based microarray analysis after hematopoietic stem cell transplantation.

Viral infections are important causes of morbidity and mortality in patients after hematopoietic stem cell transplantation. The monitoring by PCR of Herpesviridae loads in blood samples has become a critical part of posttransplant follow-up, representing mounting costs for the laboratory. In this study, we assessed the clinical performance of the multiplex PCR DNA microarray Clart Entherpex kit for detection of cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human herpesvirus 6 (HHV-6) as a screening test for virological follow-up. Two hundred fifty-five blood samples from 16 transplanted patients, prospectively tested by routine PCR assays, were analyzed by microarray. Routine PCR detected single or multiple viruses in 42% and 10% of the samples, respectively. Microarray detected single or multiple viruses in 34% and 18% of the samples, respectively. Microarray results correlated well with CMV and EBV detections by routine PCR (kappa tests = 0.79 and 0.78, respectively), whereas a weak correlation was observed with HHV-6 (0.43). HHV-7 was also detected in 48 samples by microarray. In conclusion, the microarray is a reliable screening assay for a posttransplant virological follow-up to detect CMV and EBV infections in blood. However, positive samples must be subsequently confirmed and viral loads must be quantified by PCR assays. Limitations were identified regarding HHV-6 detection. Although it is promising, is easy to use as a first-line test, and allows a reduction in the cost of analysis without undue delay in the reporting of the final quantitative result to the clinician, some characteristics of this microarray should be improved, particularly regarding quality control and the targeted virus panel, such that it could then be used as a routine test.

Assessment of the diagnostic performances of IgA heavy and light chain pairs in patients with IgA monoclonal gammopathy.

OBJECTIVES: Preliminary results of the IgA Hevylite™ assay including the establishment of the 95% reference interval and assessment of the specificity and sensitivity in different populations are reported. DESIGN AND METHODS: The concentrations of IgA heavy and light chains (HLC) enabling to determine an IgAκ/IgAλ ratio were quantified in 119 apparently healthy individuals to generate 95% reference intervals. The specificity of this assay was assessed in 48 patients with an isolated polyclonal IgA increase. In a retrospective analysis of 68 patients with a monoclonal component type IgA (MC-IgA) identified by serum immunofixation (IFE), IgA HLC ratio values were compared with known results for serum protein electrophoresis (SPE) and free light chain (FLC) ratios. RESULTS: The 95% reference range obtained in 119 controls (0.91-2.04) was close to that quoted by the manufacturer (0.80-2.04). Eight of the 48 patients (16.7%) with a polyclonal IgA increase had an IgA HLC ratio above the upper limit of the 95% reference interval. The IgA HLC ratio identified 65 (95.6%) among 68 patients with MC-IgA identified on the basis of IFE. For 34 of these patients (50%), MC-IgA was not detected by SPE due to its co-migration with alpha-2 or beta-globulins. CONCLUSIONS: Compared with serum IFE, the IgA HLC ratio has a sensitivity of 95.6%. Further studies are needed to assess the specificity of the IgA HLC ratio in patients with an isolated polyclonal increase of serum IgA.

Evaluation of the procoagulant activity of endogenous phospholipids in the platelet-free plasma of children with sickle cell disease using functional assays.

BACKGROUND: The mechanisms of hypercoagulability in sickle cell disease (SCD) are poorly understood. OBJECTIVE: We aimed to explore the procoagulant activity of endogenous phospholipids (ePL) in the platelet-free plasma of SCD children. METHODS: A factor Xa clotting time (XACT), thrombin generation (TG) and a capture-based assay for the detection of procoagulant microparticles (PMP) were used. Forty three SCD children (35 SS, 6 SC and 2 Sß+) were evaluated at steady-state and compared to 20 controls. Fourteen patients were also evaluated during vaso-occlusive crisis. TG was performed using 10 pM tissue factor without addition of exogenous phospholipids. A control condition was also performed using 10 pM tissue factor and 4 µM phospholipids. Percentages of the test/control conditions were calculated for the peak height (% peak), endogenous thrombin potential (% ETP) and velocity index (% VI). RESULTS: XACT times were shorter, PMP levels, peak height and velocity index of thrombin generation were higher in SCD patients than controls. Lag time and ETP were not different between the two groups. % peak, % ETP and % VI were higher in patients than controls. Significant correlations were found between PMP levels and XACT, also between PMP levels and peak height, velocity index, ETP and their respective percentages to the control condition, but not with lag time. Double heterozygous patients showed intermediate values for XACT and TG parameters. No significant difference was observed when comparing patients at steady-state versus vaso-occlusive crisis. CONCLUSION: High procoagulant activity of ePL was observed in the platelet-free plasma of SCD children, probably borne by procoagulant microparticles. This may contribute to a high hemostatic potential and predisposition to thrombotic complications in these patients.

Thrombin generation reveals high procoagulant potential in the plasma of sickle cell disease children.

Changes in several components of the clotting system are well documented in sickle cell disease (SCD) patients. However, whether the global hemostatic potential of these patients is altered is still unclear. Calibrated automated thrombogram(®) method of thrombin generation (TG) was used to characterize the hemostatic potential of 83 SCD children (75 SS, 6 SC, and 2 Sß (thal)) at steady-state as compared with 50 controls of the same range of age. TG was triggered using 1 pM tissue factor and 4 µM phospholipids with and without thrombomodulin. Thirteen SCD children were also evaluated during vaso-occlusive crisis. Protein C activity, free protein S and D-dimers levels were measured in parallel. SCD patients showed higher rates of thrombin formation, higher thrombin peak height (with and without thrombomodulin), and higher endogenous thrombin potential (ETP) than controls in the presence of thrombomodulin. Reduction of ETP (RETP) in the presence of thrombomodulin was lower in SCD group compared with controls and correlated both with protein C and protein S levels. ETP, RETP, peak height, and velocity index of TG correlated with D-dimers. Compound heterozygous patients showed an intermediate hemostatic phenotype at steady-state. No significant difference was observed when comparing TG parameters during vaso-occlusive crisis to those obtained at steady-state in the same patients. The global hemostatic potential is increased and reflects the hypercoagulable state of SCD patients even at steady-state. The relevance of this finding with respect to the risk of thrombotic complications of the disease needs further investigation.

Erythrocyte membrane protein analysis by sodium dodecyl sulphate-capillary gel electrophoresis in the diagnosis of hereditary spherocytosis.

BACKGROUND: Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) is currently the reference method for detecting protein deficiencies related to hereditary spherocytosis. The aim of the study was to evaluate an automated capillary gel electrophoresis system, the Experion instrument from BioRad, for its ability to separate and quantify the erythrocyte membrane proteins. METHODS: The major erythrocyte membrane proteins (actin, protein 4.2, protein 4.1, band 3, ankyrin, α- and ß-spectrin) were extracted and purified from membrane ghosts by centrifugation, immunoprecipitation and electroelution. Analyses were performed using SDS-PAGE and sodium dodecyl sulphate capillary gel electrophoresis (SDS-CGE) to establish a separation profile of the total ghosts. Then, the samples from patients received for investigations of erythrocyte membrane defects were analysed. RESULTS: Five of the seven expected erythrocyte membrane proteins were finally separated and identified. In the 20 studied cases, taking into account the screening test results and the clinical and family histories, the SDS-CGE method allowed us to achieve the same conclusion as with SDS-PAGE, except for the patient with elliptocytosis. CONCLUSIONS: The new SDS-CGE method presents interesting features that could make this instrument a powerful diagnostic tool for detection of erythrocyte membrane protein abnormalities, and can be proposed as an automated alternative method to the labour intensive SDS-PAGE analysis.

Evaluation of the procoagulant activity in the plasma of cancer patients using a thrombin generation assay.

INTRODUCTION: Circulating microparticles are reported to play a role in cancer hypercoagulability. The procoagulant properties of microparticles derive from the amount of tissue factor and/or phosphatidylserine that they can expose. The aim of our study is to assess the procoagulant activity, including microparticles' activity, in the plasma of newly diagnosed cancer patients with a simple assay, easy to implement in the laboratory. MATERIAL AND METHODS: Newly diagnosed cancer patients (n=31) before the start of anticoagulant or chemotherapy were compared to matched controls. We used a thrombin generation assay in four conditions: 1: addition of 1 pM tissue factor and 4 µM procoagulant phospholipids, 2: without any trigger, 3 and 4: addition of tissue factor or procoagulant phospholipids alone respectively. RESULTS: When we added only phospholipids, so that thrombin generation is dependent upon endogenous tissue factor, the lag time was significantly shorter in cancer patients. When we added only tissue factor, i.e. made the results dependent upon phospholipids, the endogenous thrombin potential, the peak, and the velocity index were significantly higher and the time-to-peak was significantly shorter. This suggests that the plasma of cancer patients contained a higher activity of endogenous phospholipids and/or tissue factor which may be borne by microparticles. CONCLUSION: This new simple methodology can demonstrate a procoagulant activity in the plasma of newly diagnosed cancer patients which can be explained by higher procoagulant phospholipids and tissue factor activity and thus, brings potentially useful information that current coagulation tests cannot provide.