Recommendations for the use of anti-dsDNA autoantibodies in the diagnosis and follow-up of systemic lupus erythematosus - A proposal from an expert panel

Anti-dsDNA autoantibodies are listed as one of the classification criteria for systemic lupus erythematosus (SLE) and are relatively effective indicators for monitoring disease activity and treatment response. Therefore, clinicians rely on them to diagnose and adjust medication and treatment strategies for SLE patients. However, the use of anti-dsDNA antibodies is not free from controversy. Part of this controversy stems from the fact that anti-dsDNA antibodies are found in several disorders, besides SLE. In addition to this, anti-dsDNA antibodies are a heterogeneous group of antibodies, and their determination still lacks proper standardization. Moreover, anti-dsDNA testing specificity and diagnostic performance change depending on the population under study. These and other issues result in inconsistency and encumber the clinical use of anti-dsDNA antibodies. A panel of medical laboratory and clinical experts on SLE discussed such issues based on their clinical experience in a first meeting, establishing a series of recommendations. The proceedings of this first meeting, plus an exhaustive review of the literature, were used to compose a paper draft. The panel subsequently discussed and refined this draft in a second meeting, the result of which is this paper. This document is relevant to clinical laboratories as it guides to improving diagnosis and monitoring of SLE. Simultaneously, it will help laboratories compile more informative reports, not limited to a mere number. It is also relevant to clinical doctors who wish to better understand laboratory methods so that they can do a more efficient, better-aimed laboratory test ordering.

In-depth blood immune profiling of Good syndrome patients

Introduction

Good syndrome (GS) is a rare adult-onset immunodeficiency first described in 1954. It is characterized by the coexistence of a thymoma and hypogammaglobulinemia, associated with an increased susceptibility to infections and autoimmunity. The classification and management of GS has been long hampered by the lack of data about the underlying immune alterations, a controversy existing on whether it is a unique diagnostic entity vs. a subtype of Common Variable Immune Deficiency (CVID).

Methods

Here, we used high-sensitive flow cytometry to investigate the distribution of up to 70 different immune cell populations in blood of GS patients (n=9) compared to age-matched CVID patients (n=55) and healthy donors (n=61).

Results

All 9 GS patients displayed reduced B-cell counts -down to undetectable levels (<0.1 cells/μL) in 8/9 cases-, together with decreased numbers of total CD4+ T-cells, NK-cells, neutrophils, and basophils vs. age-matched healthy donors. In contrast, they showed expanded TCRγδ+ T-cells (p ≤ 0.05). Except for a deeper B-cell defect, the pattern of immune cell alteration in blood was similar in GS and (age-matched) CVID patients. In depth analysis of CD4+ T-cells revealed significantly decreased blood counts of naïve, central memory (CM) and transitional memory (TM) TCD4+ cells and their functional compartments of T follicular helper (TFH), regulatory T cells (Tregs), T helper (Th)2, Th17, Th22, Th1/Th17 and Th1/Th2 cells. In addition, GS patients also showed decreased NK-cell, neutrophil, basophil, classical monocyte and of both CD1c+ and CD141+ myeloid dendritic cell counts in blood, in parallel to an expansion of total and terminal effector TCRγδ+ T-cells. Interestingly, those GS patients who developed hypogammaglobulinemia several years after the thymoma presented with an immunological and clinical phenotype which more closely resembled a combined immune humoral and cellular defect, with poorer response to immunoglobulin replacement therapy, as compared to those in whom the thymoma and hypogammaglobulinemia were simultaneously detected.

Discussion

Our findings provide a more accurate definition of the immune cell defects of GS patients and contribute to a better discrimination among GS patients between those with a pure B-cell defect vs. those suffering from a combined immunodeficiency with important consequences on the diagnosis and management of the disease.

Laboratory and clinical practices in antinuclear antibody detection and related antigens: recommendations from a Spanish multicentre survey

Antinuclear antibodies (ANA) are the most widely used immunological test for the diagnosis of autoimmune diseases. Despite the recommendations of experts, there is some variability in performing and interpreting this test in routine practice. In this context, the Spanish Group on Autoimmune Diseases (GEAI) of the Spanish Society of Immunology (SEI) conducted a national survey of 50 autoimmunity laboratories. Here we report the survey results on ANA testing, detection of related antigens, and our recommendations. The survey showed that most of the participating laboratories use a similar approach for most key practices: 84% perform ANA by indirect immunofluorescence (IIF) on HEp-2 cells as the screening methodology while the other laboratories use IIF to confirm positive screens; 90% report ANA test results as either negative or positive with titer and pattern; 86% indicated that the ANA pattern conditioned follow-up testing for specific antigen-related antibodies; and 70% confirm positive anti-dsDNA. However, testing practices were highly heterogeneous for certain items, such as sera dilutions and the minimum time period for repeating ANA and related antigen determinations. Overall, this survey shows that most autoimmune laboratories in Spain use a similar approach but that further standardization of testing and reporting protocols is needed.

Brain fog of post-COVID-19 condition and Chronic Fatigue Syndrome, same medical disorder?

BACKGROUND

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is characterized by persistent physical and mental fatigue. The post-COVID-19 condition patients refer physical fatigue and cognitive impairment sequelae. Given the similarity between both conditions, could it be the same pathology with a different precipitating factor?

OBJECTIVE

To describe the cognitive impairment, neuropsychiatric symptoms, and general symptomatology in both groups, to find out if it is the same pathology. As well as verify if the affectation of smell is related to cognitive deterioration in patients with post-COVID-19 condition.

METHODS

The sample included 42 ME/CFS and 73 post-COVID-19 condition patients. Fatigue, sleep quality, anxiety and depressive symptoms, the frequency and severity of different symptoms, olfactory function and a wide range of cognitive domains were evaluated.

RESULTS

Both syndromes are characterized by excessive physical fatigue, sleep problems and myalgia. Sustained attention and processing speed were impaired in 83.3% and 52.4% of ME/CFS patients while in post-COVID-19 condition were impaired in 56.2% and 41.4% of patients, respectively. Statistically significant differences were found in sustained attention and visuospatial ability, being the ME/CFS group who presented the worst performance. Physical problems and mood issues were the main variables correlating with cognitive performance in post-COVID-19 patients, while in ME/CFS it was anxiety symptoms and physical fatigue.

CONCLUSIONS

The symptomatology and cognitive patterns were similar in both groups, with greater impairment in ME/CFS. This disease is characterized by greater physical and neuropsychiatric problems compared to post-COVID-19 condition. Likewise, we also propose the relevance of prolonged hyposmia as a possible marker of cognitive deterioration in patients with post-COVID-19.

Autoimmune GFAP astrocytopathy presenting with remarkable CNS hyperexcitability and oculogyric crises

The autoimmune GFAP astrocytopathy has been associated with meningoencephalomyelitis that usually responds to glucocorticoids. We report a 20-year-old man that developed an acute and severe meningoencephalomyelitis with remarkable CNS hyperexcitability and oculogyric crises. CSF analysis showed hypoglycorrhachia, pleocytosis, elevated ADA, and CSF-immunofluorescence characteristic of autoimmune GFAP astrocytopathy. MRI showed lesions at thalamus, corpus-callosum, dorsal pons and dentate nucleus with associated myelitis. Immunotherapy led to a full recovery, although MRI activity was observed at follow-up. CNS hyperexcitability, typically seen in other immune-mediated syndromes, represents a novel presenting form to be included as part of the clinical spectrum of this entity.

The age again in the eye of the COVID-19 storm: evidence-based decision making

BACKGROUND

One hundred fifty million contagions, more than 3 million deaths and little more than 1 year of COVID-19 have changed our lives and our health management systems forever. Ageing is known to be one of the significant determinants for COVID-19 severity. Two main reasons underlie this: immunosenescence and age correlation with main COVID-19 comorbidities such as hypertension or dyslipidaemia. This study has two aims. The first is to obtain cut-off points for laboratory parameters that can help us in clinical decision-making. The second one is to analyse the effect of pandemic lockdown on epidemiological, clinical, and laboratory parameters concerning the severity of the COVID-19. For these purposes, 257 of SARSCoV2 inpatients during pandemic confinement were included in this study. Moreover, 584 case records from a previously analysed series, were compared with the present study data.

RESULTS

Concerning the characteristics of lockdown series, mild cases accounted for 14.4, 54.1% were moderate and 31.5%, severe. There were 32.5% of home contagions, 26.3% community transmissions, 22.5% nursing home contagions, and 8.8% corresponding to frontline worker contagions regarding epidemiological features. Age > 60 and male sex are hereby confirmed as severity determinants. Equally, higher severity was significantly associated with higher IL6, CRP, ferritin, LDH, and leukocyte counts, and a lower percentage of lymphocyte, CD4 and CD8 count. Comparing this cohort with a previous 584-cases series, mild cases were less than those analysed in the first moment of the pandemic and dyslipidaemia became more frequent than before. IL-6, CRP and LDH values above 69 pg/mL, 97 mg/L and 328 U/L respectively, as well as a CD4 T-cell count below 535 cells/μL, were the best cut-offs predicting severity since these parameters offered reliable areas under the curve.

CONCLUSION

Age and sex together with selected laboratory parameters on admission can help us predict COVID-19 severity and, therefore, make clinical and resource management decisions. Demographic features associated with lockdown might affect the homogeneity of the data and the robustness of the results.

Whole-Transcriptome Analysis in Peripheral Blood Mononuclear Cells from Patients with Lipid-Specific Oligoclonal IgM Band Characterization Reveals Two Circular RNAs and Two Linear RNAs as Biomarkers of Highly Active Disease

The presence of anti-myelin lipid-specific oligoclonal IgM bands (LS-OCMBs) has been defined as an accurate predictor of an aggressive evolution of multiple sclerosis. However, the detection of this biomarker is performed in cerebrospinal fluid, a quite invasive liquid biopsy. In the present study we aimed at studying the expression profile of miRNA, snoRNA, circRNA and linearRNA in peripheral blood mononuclear cells (PBMCs) from patients with lipid-specific oligoclonal IgM band characterization. We included a total of 89 MS patients, 47 with negative LS-OCMB status and 42 with positive status. Microarray (miRNA and snoRNA) and RNA-seq (circular and linear RNAs) were used to perform the profiling study in the discovery cohort and candidates were validated by RT-qPCR in the whole cohort. The biomarker potential of the candidates was evaluated by ROC curve analysis. RNA-seq and RT-qPCR validation revealed that two circular (hsa_circ_0000478 and hsa_circ_0116639) and two linear RNAs (IRF5 and MTRNR2L8) are downregulated in PBMCs from patients with positive LS-OCMBs. Finally, those RNAs show a performance of a 70% accuracy in some of the combinations. The expression of hsa_circ_0000478, hsa_circ_0116639, IRF5 and MTRNR2L8 might serve as minimally invasive biomarkers of highly active disease.

COVID-19: age, Interleukin-6, C-reactive protein, and lymphocytes as key clues from a multicentre retrospective study

Background

The SARS-CoV-2 infection has widely spread to become the greatest public health challenge to date, the COVID-19 pandemic. Different fatality rates among countries are probably due to non-standardized records being carried out by local health authorities. The Spanish case-fatality rate is 11.22%, far higher than those reported in Asia or by other European countries. A multicentre retrospective study of demographic, clinical, laboratory and immunological features of 584 Spanish COVID-19 hospitalized patients and their outcomes was performed. The use of renin-angiotensin system blockers was also analysed as a risk factor.

Results

In this study, 27.4% of cases presented a mild course, 42.1% a moderate one and for 30.5% of cases, the course was severe. Ages ranged from 18 to 98 (average 63). Almost 60 % (59.8%) of patients were male. Interleukin 6 was higher as severity increased. On the other hand, CD8 lymphocyte count was significantly lower as severity grew and subpopulations CD4, CD8, CD19, and NK showed concordant lowering trends. Severity-related natural killer percent descents were evidenced just within aged cases. A significant severity-related decrease of CD4 lymphocytes was found in males. The use of angiotensin-converting enzyme inhibitors was associated with a better prognosis. The angiotensin II receptor blocker use was associated with a more severe course.

Conclusions

Age and age-related comorbidities, such as dyslipidaemia, hypertension or diabetes, determined more frequent severe forms of the disease in this study than in previous literature cohorts. Our cases are older than those so far reported and the clinical course of the disease is found to be impaired by age. Immunosenescence might be therefore a suitable explanation for the hampering of immune system effectors. The adaptive immunity would become exhausted and a strong but ineffective and almost deleterious innate response would account for COVID-19 severity. Angiotensin-converting enzyme inhibitors used by hypertensive patients have a protective effect in regards to COVID-19 severity in our series. Conversely, patients on angiotensin II receptor blockers showed a severer disease.

Multi-centre validation of a flow cytometry method to identify optimal responders to interferon-beta in multiple sclerosis

BACKGROUND AND OBJECTIVES

Percentages of blood CD19+CD5+ B cells and CD8+perforin+ T lymphocytes can predict response to Interferon (IFN)-beta treatment in relapsing-remitting multiple sclerosis (RRMS) patients. We aimed to standardize their detection in a multicenter study, prior to their implementation in clinical practice.

METHODS

Fourteen hospitals participated in the study. A reference centre was established for comparison studies. Peripheral blood cells of 105 untreated RRMS patients were studied. Every sample was analyzed in duplicate in the participating centre and in the reference one by flow cytometry. When needed, participating centres corrected fluorescence compensations and negative cut-off position following reference centre suggestions. Concordance between results obtained by participating centres and by reference one was evaluated by intraclass correlation coefficients (ICC) and Spearman correlation test. Centre performance was measured by using z-scores values.

RESULTS

After results review and corrective actions implementation, overall ICC was 0.86 (CI: 0.81-0.91) for CD19+CD5+ B cell and 0.89 (CI: 0.85-0.93) for CD8+ perforin+ T cell quantification; Spearman r was 0.92 (0.89-0.95; p <0.0001) and 0.92 (0.88-0.95; p <0.0001) respectively. All centres obtained z-scores≤0.5 for both biomarkers.

CONCLUSION

Homogenous percentages of CD19+CD5+ B cells and CD8 perforin+ T lymphocytes can be obtained if suitable compensation values and negative cut-off are pre-established.

The First Dose of Fingolimod Affects Circulating Extracellular Vesicles in Multiple Sclerosis Patients

Extracellular vesicles (EVs) are membrane-bound particles involved in intercellular communication. They carry proteins, lipids, and nucleotides such as microRNAs (miRNAs) from the secreting cell that can modulate target cells. We and others have previously described the presence of EVs in peripheral blood of multiple sclerosis (MS) patients and postulated them as novel biomarkers. However, their immune function in MS pathogenesis and the effect during the onset of new immunomodulatory therapies on EVs remain elusive. Here, we isolated plasma EVs from fingolimod-treated MS patients in order to assess whether EVs are affected by the first dose of the treatment. We quantified EVs, analyzed their miRNA cargo, and checked their immune regulatory function. Results showed an elevated EV concentration with a dramatic change in their miRNA cargo 5 h after the first dose of fingolimod. Besides, EVs obtained prior to fingolimod treatment showed an increased immune regulatory activity compared to EVs obtained 5 h post-treatment. This work suggests that EVs are implicated in the mechanism of action of immunomodulatory treatments from the initial hours and opens a new avenue to explore a potential use of EVs for early treatment monitoring.

Transcriptomic profile reveals gender-specific molecular mechanisms driving multiple sclerosis progression

Background

Although the most common clinical presentation of multiple sclerosis (MS) is the so called Relapsing-Remitting MS (RRMS), the molecular mechanisms responsible for its progression are currently unknown. To tackle this problem, a whole-genome gene expression analysis has been performed on RRMS patients.

Results

The comparative analysis of the Affymetrix Human Gene 1.0 ST microarray data from peripheral blood leucocytes obtained from 25 patients in remission and relapse and 25 healthy subjects has revealed 174 genes altered in both remission and relapse, a high proportion of them showing what we have called “mirror pattern”: they are upregulated in remission and downregulated in relapse or vice versa. The coexpression analysis of these genes has shown that they are organized in three female-specific and one male-specific modules.

Conclusions

The interpretation of the modules of the coexpression network suggests that Epstein-Barr virus (EBV) reactivation of B cells happens in MS relapses; however, qPCR expression data of the viral genes supports that hypothesis only in female patients, reinforcing the notion that different molecular processes drive disease progression in females and males. Besides, we propose that the “primed” state showed by neutrophils in women is an endogenous control mechanism triggered to keep EBV reactivation under control through vitamin B12 physiology. Finally, our results also point towards an important sex-specific role of non-coding RNA in MS.