Autoantibodies against type I IFNs in humans with alternative NF-κB pathway deficiency.

Patients with autoimmune polyendocrinopathy syndrome type 1 (APS-1) caused by autosomal recessive AIRE deficiency produce autoantibodies that neutralize type I interferons (IFNs)1,2, conferring a predisposition to life-threatening COVID-19 pneumonia3. Here we report that patients with autosomal recessive NIK or RELB deficiency, or a specific type of autosomal-dominant NF-κB2 deficiency, also have neutralizing autoantibodies against type I IFNs and are at higher risk of getting life-threatening COVID-19 pneumonia. In patients with autosomal-dominant NF-κB2 deficiency, these autoantibodies are found only in individuals who are heterozygous for variants associated with both transcription (p52 activity) loss of function (LOF) due to impaired p100 processing to generate p52, and regulatory (IκBδ activity) gain of function (GOF) due to the accumulation of unprocessed p100, therefore increasing the inhibitory activity of IκBδ (hereafter, p52LOF/IκBδGOF). By contrast, neutralizing autoantibodies against type I IFNs are not found in individuals who are heterozygous for NFKB2 variants causing haploinsufficiency of p100 and p52 (hereafter, p52LOF/IκBδLOF) or gain-of-function of p52 (hereafter, p52GOF/IκBδLOF). In contrast to patients with APS-1, patients with disorders of NIK, RELB or NF-κB2 have very few tissue-specific autoantibodies. However, their thymuses have an abnormal structure, with few AIRE-expressing medullary thymic epithelial cells. Human inborn errors of the alternative NF-κB pathway impair the development of AIRE-expressing medullary thymic epithelial cells, thereby underlying the production of autoantibodies against type I IFNs and predisposition to viral diseases.

Prognosis and long-term outcomes in type I cryoglobulinemia: A multicenter study of 168 patients.

Type I cryoglobulinemia (CG) accounts for 10%-15% of all cryoglobulinemias and are exclusively seen in clonal proliferative hematologic conditions. In this multicenter nationwide cohort study, we analyzed the prognosis and long-term outcomes of 168 patients with type I CG (93 (55.4%) IgM and 75 [44.6%] IgG). Five- and 10-year event-free survivals (EFS) were 26.5% (95% CI 18.2%-38.4%) and 20.8% (95% CI 13.1%-33.1%), respectively. In multivariable analysis, factors associated with poorer EFS were renal involvement (HR: 2.42, 95% CI 1.41-4.17, p = .001) and IgG type I CG (HR: 1.96, 95% CI 1.13-3.33, p = 0.016), regardless of underlying hematological disorders. IgG type I CG patients had higher cumulative incidence of relapse (94.6% [95% CI 57.8%-99.4%] vs. 56.6% [95% CI 36.6%-72.4%], p = .0002) and death at 10 years (35.8% [19.8%-64.6%] vs. 71.3% [54.0%-94.2%], p = .01) as compared to IgM CG, respectively. Overall, complete response of type I CG at 6 months was 38.7%, with no significant difference between Igs isotypes. In conclusion, renal involvement and IgG CG were identified as independent poor prognostic factors of type I CG.

Serum vascular endothelial growth factor is associated with cardiovascular involvement and response to therapy in Erdheim-Chester disease.

Erdheim-Chester disease (ECD) is a rare histiocytosis, considered to be an inflammatory myeloid neoplasm. Tropism for specific involvements of the disease remains unexplained. Vascular endothelial growth factor-A (VEGF) is implicated in cancer pathophysiology and mutations of the RAS oncogene have been shown to induce upregulation of VEGF gene expression. We therefore hypothesized that VEGF might play a particular role in ECD pathophysiology. We conducted a retrospective, single-center study to assess serum VEGF (sVEGF) concentrations and determine whether they were associated with the characteristics of ECD patients, and to determine whether VEGF was expressed by histiocytes. We evaluated 247 ECD patients, 53.4% of whom had sVEGF levels above the normal range (>500 pg/mL). Patients with high sVEGF levels more frequently had cardiac and vascular involvement (58.3% vs. 41.4%, P=0.008 and 70.5% vs. 48.3%, P=0.0004, respectively). In treatment-naïve patients (n=135), the association of C-reactive protein >5 mg/L and sVEGF >500 pg/mL was strongly associated with vascular involvement (odds ratio=5.54 [95% confidence interval: 2.39-13.62], P<0.001), and independently associated with cardiac involvement (odds ratio=3.18 [95% confidence interval: 1.34-7.83], P=0.010) after adjustment for the presence of the BRAF V600E mutation. Changes in sVEGF concentration on treatment were associated with a response of cardiac involvement on consecutive cardiac magnetic resonance images. All histological samples analyzed (n=24) displayed histiocytes with intracytoplasmic expression of VEGF, which was moderate to high in more than 90% of cases. Our study suggests a role for VEGF in cardiac and vascular involvement in ECD.

Lower disease activity but higher risk of severe COVID-19 and herpes zoster in patients with systemic lupus erythematosus with pre-existing autoantibodies neutralising IFN-α.

OBJECTIVES: Type-I interferons (IFNs-I) have potent antiviral effects. IFNs-I are also overproduced in patients with systemic lupus erythematosus (SLE). Autoantibodies (AAbs) neutralising IFN-α, IFN-ß and/or IFN-ω subtypes are strong determinants of hypoxemic COVID-19 pneumonia, but their impact on inflammation remains unknown. METHODS: We retrospectively analysed a monocentric longitudinal cohort of 609 patients with SLE. Serum AAbs against IFN-α were quantified by ELISA and functionally assessed by abolishment of Madin-Darby bovine kidney cell protection by IFN-α2 against vesicular stomatitis virus challenge. Serum-neutralising activity against IFN-α2, IFN-ß and IFN-ω was also determined with a reporter luciferase activity assay. SARS-CoV-2 antibody responses were measured against wild-type spike antigen, while serum-neutralising activity was assessed against the SARS-CoV-2 historical strain and variants of concerns. RESULTS: Neutralising and non-neutralising anti-IFN-α antibodies are present at a frequency of 3.3% and 8.4%, respectively, in individuals with SLE. AAbs neutralising IFN-α, unlike non-neutralising AAbs, are associated with reduced IFN-α serum levels and a reduced likelihood to develop active disease. However, they predispose patients to an increased risk of herpes zoster and severe COVID-19 pneumonia. Severe COVID-19 pneumonia in patients with SLE is mostly associated with combined neutralisation of different IFNs-I. Finally, anti-IFN-α AAbs do not interfere with COVID-19 vaccine humoral immunogenicity. CONCLUSION: The production of non-neutralising and neutralising anti-IFN-I antibodies in SLE is likely to be a consequence of SLE-associated high IFN-I serum levels, with a beneficial effect on disease activity, yet a greater viral risk. This finding reinforces the recommendations for vaccination against SARS-CoV-2 in SLE.

Immunochemotherapy versus rituximab in anti-myelin-associated glycoprotein neuropathy: A report of 64 patients.

Monoclonal immunoglobulin M (IgM) anti-myelin-associated glycoprotein (MAG) neuropathy is a rare disabling condition, most commonly treated with rituximab monotherapy (R), which leads to neurological improvement in only 30%-50% of patients. The combination of rituximab plus chemotherapy has been proven to improve the level of responses. We studied the outcomes of anti-MAG neuropathy patients treated either by R, or by immunochemotherapy (ICT) in our centre, focusing on the incidence of the first neurological response evaluated by the modified Rankin scale (mRS). From 2011 to 2018, 64 patients were studied: 34 were treated with R and 30 with ICT. According to our treatment decision-making process, the median mRS was higher in the ICT group (mRS 2) than in the R group (mRS 1). At one year, improvements of the mRS rates were 46% and 18% in the ICT and R groups of patients respectively, with median times to response of eight and 13 months (p = 0.023). Adverse effects were higher in the ICT group: 62% vs 15% (p Ë‚ 0.01), all grades included. One secondary acute leukaemia occurred five years after treatment with ICT. In conclusion, ICT may be used as a valid option for patients with rapidly progressive and/or severe anti-MAG neuropathy symptoms.

Clonal haematopoiesis of indeterminate potential and cardiovascular events in systemic lupus erythematosus (HEMATOPLUS study).

OBJECTIVE: The detection of somatic mutations among the genes of myeloid cells in asymptomatic patients-defining clonal haematopoiesis of indeterminate potential (CHIP)-is associated with a predisposition to cardiovascular events (CVEs) in the general population. We aimed to determine whether CHIP was associated with CVEs in SLE patients. METHODS: The study is an ancillary study of the randomized, double-blind, placebo-controlled, multicentre PLUS trial conducted from June 2007 through August 2010 at 37 centres in France, involving 573 SLE patients. The search for somatic mutations by high-throughput sequencing of 53 genes involved in clonal haematopoiesis was performed on genomic DNA collected at PLUS inclusion. CHIP prevalence was assessed in SLE and in a retrospective cohort of 479 patients free of haematological malignancy. The primary outcome was an incident CVE in SLE. RESULTS: Screening for CHIP was performed in 438 SLE patients [38 (29-47) years, 91.8% female]. Overall, 63 somatic mutations were identified in 47 patients, defining a CHIP prevalence of 10.7% in SLE. Most SLE patients (78.7%) carried a single mutation. Most variants (62.5%) were located in the DNMT3A gene. CHIP frequency was related to age and to age at SLE diagnosis, and was associated with a lower frequency of aPLs. CHIP occurred >20 years earlier (P < 0.00001) in SLE than in controls. The detection of CHIP at inclusion was not found to be associated with occurrence of CVEs during follow-up [HR = 0.42 (0.06-3.21), P = 0.406]. CONCLUSION: The prevalence of CHIP is relatively high in SLE for a given age, but was not found to be associated with incident CVEs. TRIAL REGISTRATION: ClinicalTrials.gov, https://clinicaltrials.gov, NCT05146414.

BNT162b2 vaccine-induced humoral and cellular responses against SARS-CoV-2 variants in systemic lupus erythematosus.

OBJECTIVES: Our aim was to evaluate systemic lupus erythematosus (SLE) disease activity and SARS-CoV-2-specific immune responses after BNT162b2 vaccination. METHODS: In this prospective study, disease activity and clinical assessments were recorded from the first dose of vaccine until day 15 after the second dose in 126 patients with SLE. SARS-CoV-2 antibody responses were measured against wild-type spike antigen, while serum-neutralising activity was assessed against the SARS-CoV-2 historical strain and variants of concerns (VOCs). Vaccine-specific T cell responses were quantified by interferon-γ release assay after the second dose. RESULTS: BNT162b2 was well tolerated and no statistically significant variations of BILAG (British Isles Lupus Assessment Group) and SLEDAI (SLE Disease Activity Index) scores were observed throughout the study in patients with SLE with active and inactive disease at baseline. Mycophenolate mofetil (MMF) and methotrexate (MTX) treatments were associated with drastically reduced BNT162b2 antibody response (ß=-78, p=0.007; ß=-122, p<0.001, respectively). Anti-spike antibody response was positively associated with baseline total immunoglobulin G serum levels, naïve B cell frequencies (ß=2, p=0.018; ß=2.5, p=0.003) and SARS-CoV-2-specific T cell response (r=0.462, p=0.003). In responders, serum neutralisation activity decreased against VOCs bearing the E484K mutation but remained detectable in a majority of patients. CONCLUSION: MMF, MTX and poor baseline humoral immune status, particularly low naïve B cell frequencies, are independently associated with impaired BNT162b2 mRNA antibody response, delineating patients with SLE who might need adapted vaccine regimens and follow-up.

Highly sensitive serum cardiac troponin T and cardiovascular events in patients with systemic lupus erythematosus (TROPOPLUS study).

OBJECTIVE: Identification of biological markers able to better stratify cardiovascular risks in SLE patients is needed. We aimed to determine whether serum cardiac troponin T (cTnT) levels measured with a highly sensitive assay [high sensitivity cTnT (HS-cTnT)] may predict cardiovascular events (CVEs) in SLE. METHOD: All SLE patients included between 2007 and 2010 in the randomized, double-blind, placebo-controlled, multicentre PLUS trial were screened. Patients with no past history of CVE at inclusion and a follow-up period of >20 months were analysed. HS-cTnT concentration was measured using the electrochemiluminescence method on serum collected at PLUS inclusion. The primary outcome was the incident CVE. Factors associated with the primary outcome were identified and multivariate analysis was performed. RESULTS: Overall, 442 SLE patients (of the 573 included in the PLUS study) were analysed for the primary outcome with a median follow up of 110 (interquartile range: 99-120) months. Among them, 29 (6.6%) experienced at least one CVE that occurred at a median of 67 (interquartile range: 31-91) months after inclusion. Six out of 29 patients had more than one CVE. In the multivariate analysis, dyslipidaemia, age and HS-cTnT were associated with the occurrence of CVE. Kaplan-Meier analysis showed that a concentration of HS-cTnT > 4.27 ng/l at inclusion increased by 2.7 [hazard ratio 2.7 (95% CI: 1.3, 5.6), P =0.0083] the risk of CVE in SLE. CONCLUSION: HS-cTnT measured in serum is the first identified biomarker independently associated with incident CVE in SLE patients.

Systemic anti-commensal response to fungi analyzed by flow cytometry is related to gut mycobiome ecology.

BACKGROUND: Interest for the study of gut mycobiota in relation with human health and immune homeostasis has increased in the last years. From this perspective, new tools to study the immune/fungal interface are warranted. Systemic humoral immune responses could reflect the dynamic relationships between gut mycobiota and immunity. Using a novel flow cytometry technology (Fungi-Flow) to determine immunoglobulin (Ig) responses to fungi, we studied the relationships between gut mycobiota and systemic humoral anti-commensal immunity. RESULTS: The Fungi-Flow method allows a sensitive and specific measurement of systemic IgG responses against 17 commensal and environmental fungi from the two main divisions; Ascomycota and Basidiomycota. IgG responses exhibited a high inter-individual variability. Anti-commensal IgG responses were contrasted with the relative abundance, alpha-diversity, and intra-genus richness of fungal species in gut mycobiota of twenty healthy donors. Categorization of gut mycobiota composition revealed two differentiated fungal ecosystems. Significant difference of anti-Saccharomyces systemic IgG responses were observed in healthy donors stratified according to the fungal ecosystem colonizing their gut. A positive and significant correlation was observed between the variety of IgG responses against fungal commensals and intestinal alpha-diversity. At the level of intra-genus species richness, intense IgG responses were associated with a low intra-genus richness for known pathobionts, but not commensals. CONCLUSIONS: Fungi-Flow allows an easy and reliable measure of personalized humoral responses against commensal fungi. Combining sequencing technology with our novel Fungi-Flow immunological method, we propose that there are at least two defined ecosystems in the human gut mycobiome associated with systemic humoral responses. Fungi-Flow opens new opportunities to improve our knowledge about the impact of mycobiota in humoral anti-commensal immunity and homeostasis. Video Abstract.

Hydroxychloroquine levels in patients with systemic lupus erythematosus: whole blood is preferable but serum levels also detect non-adherence.

BACKGROUND: Hydroxychloroquine (HCQ) levels can be measured in both serum and whole blood. No cut-off point for non-adherence has been established in serum nor have these methods ever been compared. The aims of this study were to compare these two approaches and determine if serum HCQ cut-off points can be established to identify non-adherent patients. METHODS: HCQ levels were measured in serum and whole blood from 573 patients with systemic lupus erythematosus (SLE). The risk factors for active SLE (SLEDAI score > 4) were identified by multiple logistic regression. Serum HCQ levels were measured in 68 additional patients known to be non-adherent, i.e. with whole-blood HCQ < 200 ng/mL. RESULTS: The mean (± SD) HCQ levels were 469 ± 223 ng/mL in serum and 916 ± 449 ng/mL in whole blood. The mean ratio of serum/whole-blood HCQ levels was 0.53 ± 0.15. In the multivariate analysis, low whole-blood HCQ levels (P = 0.023), but not serum HCQ levels, were independently associated with active SLE. From the mean serum/whole-blood level ratio, a serum HCQ level of 106 ng/mL was extrapolated as the corresponding cut-off to identify non-adherent patients with a sensitivity of 0.87 (95% CI 0.76-0.94) and specificity of 0.89 (95% CI 0.72-0.98). All serum HCQ levels of patients with whole-blood HCQ below the detectable level (< 20 ng/mL) were also undetectable (< 20 ng/mL). CONCLUSIONS: These data suggest that whole blood is better than serum for assessing the pharmacokinetic/pharmacodynamic relation of HCQ. Our results support the use of serum HCQ levels to assess non-adherence when whole blood is unavailable.

Cryoglobulinemia after the era of chronic hepatitis C infection.

OBJECTIVES: Historically chronic hepatitis C virus (HCV) infection accounted for the majority of mixed cryoglobulinemia (MC). The advent of direct-acting antivirals (DAA) against HCV has dramatically changed the management and the prevalence of chronic HCV infection. We aimed to describe the spectrum of MC in the era of DAA agents. METHODS: We performed a longitudinal cohort study between 2011 and 2018 from a single-center French university hospital's database of 15 970 patients screened for MC. Epidemiological, clinical and immunological data of MC were recorded. We evaluated the incidence and evolution of MC before and after the era of DAA agents and compared HCV and non-HCV related MC. RESULTS: Among 742 patients who tested positive for cryoglobulin, 679 [mean age 55.5 years, 54.5% female and 381 (56.1%) with chronic HCV infection] patients with persistent MC were included in the study. 373 (54.9%) had type II and 306 (45.1%) type III cryoglobulin, and 139 (21.5%) had cryoglobulinemia vasculitis (CryoVas). The incidence of MC decreased steadily with 395 and 284 incident cases during 2011-2014 and 2015-2018, respectively. In 2011, the leading cause was chronic HCV infection (62.5% of all MC). Currently, autoimmune diseases [systemic lupus erythematosus (28.9%) and Sjögren's syndrome (10.7%)] are the main cause of MC. The incidence of CryoVas was similar between HCV-and non HCV-related MC. CONCLUSION: Direct-acting antivirals have dramatically changed the landscape and the incidence of MC.

Synergistic convergence of microbiota-specific systemic IgG and secretory IgA.

BACKGROUND: Commensals induce local IgA responses essential to the induction of tolerance to gut microbiota, but it remains unclear whether antimicrobiota responses remain confined to the gut. OBJECTIVE: The aim of this study was to investigate systemic and intestinal responses against the whole microbiota under homeostatic conditions and in the absence of IgA. METHODS: We analyzed blood and feces from healthy donors, patients with selective IgA deficiency (SIgAd), and patients with common variable immunodeficiency (CVID). Immunoglobulin-coated bacterial repertoires were analyzed by using combined bacterial fluorescence-activated cell sorting and 16S rRNA sequencing. Bacterial lysates were probed by using Western blot analysis with healthy donor sera. RESULTS: Although absent from the healthy gut, serum antimicrobiota IgG are present in healthy subjects and increased in patients with SIgAd. IgG converges with nonoverlapping secretory IgA specificities to target the same bacteria. Each individual subject targets a diverse microbiota repertoire with a proportion that correlates inversely with systemic inflammation. Finally, intravenous immunoglobulin preparations target CVID gut microbiota much less efficiently than healthy microbiota. CONCLUSION: Secretory IgA and systemic IgG converge to target gut microbiota at the cellular level. SIgAd-associated inflammation is inversely correlated with systemic anticommensal IgG responses, which might serve as a second line of defense. We speculate that patients with SIgAd could benefit from oral IgA supplementation. Our data also suggest that intravenous immunoglobulin preparations can be supplemented with IgG from IgA-deficient patient pools to offer better protection against gut bacterial translocations in patients with CVID.

Detection in whole blood of autoantibodies for the diagnosis of connective tissue diseases in near patient testing condition.

A novel technology, photonic ring immunoassay (PRI), for detecting 12 autoantibodies simultaneously in whole blood in less than 15 minutes was evaluated by comparing results from 235 clinically diagnosed patients with standard laboratory tests. The overall agreement was greater than 91% for 10 of the 12 assays, with positive percent agreement greater than 89% for 9 of the assays and negative percent agreement greater than 91% for 10 of them. Thus, the clinical sensitivities and specificities were similar for the 2 methods. In addition, 199 normal blood donors were tested on the ANA 12 PRI, yielding specificities greater than 97.5% for all assays. This proof of concept study shows that this new system is suitable for point of care testing for clinically useful autoantibodies, allowing the doctor to have test results in minutes rather than days.

Unexpected migration of free light chains in urinary protein electrophoresis.

Urinary protein electrophoresis analysis (UPE) is an essential investigation for the study of abnormal proteins in urines. The interpretation of this analysis must be comprehensive and relevant. Indeed, UPE is often requested by clinicians and may have an important impact in patient's management. This paper presents two cases with free light chains showing unexpected electrophoretic migration which can lead to the misinterpretation of results. This article helps biologists to keep in mind the interest of UPE among the several analyses useful in the laboratory.

Thrombophilia Associated with Anti-DFS70 Autoantibodies.

CONTEXT: Anti-DFS70 antibodies are the most frequent antinuclear antibodies (ANA) found in healthy individuals. We assessed the clinical significance of the presence of anti-DFS70 antibodies. METHODS: We defined a group of patients (n = 421) with anti-DFS70 antibodies and a group of patients (n = 63) with a history of idiopathic arterial and/or venous thrombotic disease and/or obstetric complication (i.e. ≥ 3 miscarriages, fetal death or premature birth with eclampsia). Anti-DFS70 antibodies prevalence was also assessed in a cohort of 300 healthy blood donors. RESULTS: The prevalence of thrombotic disease and/or obstetric complication in the 421 patients with anti-DFS70 antibodies was 13.1% (n = 55) and the prevalence of connective tissue disease was 19% (n = 80). Among the 63 patients with a history of thrombosis and/or obstetric complications, 7 (11.1%) had anti-DFS70 antibodies and among the latter, 5 had no common thrombophilic factor. In contrast, the prevalence of anti-DFS70 antibodies was of 3.0% (9 out of 300) in healthy donors. Finally, the Activated Partial Thromboplastin Time (aPTT) ratio of patients with a history of thrombosis and anti-DFS70 antibodies was lower than the aPTT ratio of other patients, suggesting that thrombotic patients with anti-DFS70 antibodies may have a hypercoagulable state. CONCLUSION: We described here for the first time an immune procoagulant state involving anti-DFS70 antibodies.

Systemic sclerosis and prevalence of monoclonal immunoglobulin.

INTRODUCTION: The purpose of this study was to estimate the prevalence of monoclonal immunoglobulin (MIg) among patients with systemic sclerosis (SSc) according to the capillary electrophoresis or immunofixation method of detection and to search for any related clinical correlations. PATIENTS AND METHODS: Retrospective multicenter comparison of capillary electrophoresis and immunofixation results in SSc patients and of the characteristics of patients with and without MIg. RESULTS: The study included 244 SSc patients (216 women and 28 men, mean age: 55±14 years). Median time since SSc diagnosis was 51 months [0-320]; disease was diffuse in 48% of cases. Ten percent of patients had cancer, including Waldenström macroglobulinemia (n=1) and multiple myeloma (n=3). Capillary electrophoresis showed a γ-globulin anomaly in 41% of cases, and immunofixation in 18%: MIg (13.5%) and restriction of heterogeneity (4.5%). Capillary electrophoresis failed to detect 60% of the 33 MIg patients. Measurable MIg concentrations were obtained from 7 patients. MIg patients were significantly older at SSc diagnosis than those without MIg (p=0.002), had a lower diffusing capacity (p=0.002), a higher prevalence of pulmonary hypertension and cancer (p=0.002) and were more frequently positive for anti-mitochondrial and anti-beta2-glycoprotein-I antibodies (p=0.03 and p=0.02, respectively). Multivariate analyses showed that only age at test [hazard ratio 1.03 (95% CI, 1.00-1.07, p=0.04)] and presence of cancer [hazard ratio 4.46 (95% CI, 1.6-12.4, p=0.004)] were associated with MIg. CONCLUSION: Immunofixation detected a high prevalence of MIg among SSc patients especially in patients aged 50-years or older. MIg was not detected by the standard capillary electrophoresis in 60% of cases and was significantly associated with cancer.

Chronic malaria revealed by a new fluorescence pattern on the antinuclear autoantibodies test.

BACKGROUND: Several clinical forms of malaria such as chronic carriage, gestational malaria or hyper-reactive malarial splenomegaly may follow a cryptic evolution with afebrile chronic fatigue sometimes accompanied by anemia and/or splenomegaly. Conventional parasitological tests are often negative or not performed, and severe complications may occur. Extensive explorations of these conditions often include the search for antinuclear autoantibodies (ANA). METHODS: We analysed fluorescence patterns in the ANA test in patients with either chronic cryptic or acute symptomatic malaria, then conducted a one-year prospective study at a single hospital on all available sera drawn for ANA detections. We then identified autoantibodies differentially expressed in malaria patients and in controls using human protein microarray. RESULTS: We uncovered and defined a new, malaria-related, nucleo-cytoplasmic ANA pattern displaying the specific association of a nuclear speckled pattern with diffuse cytoplasmic perinuclearly-enhanced fluorescence. In the one-year prospective analysis, 79% of sera displaying this new nucleo-cytoplasmic fluorescence were from patients with malaria. This specific pattern, not seen in other parasitic diseases, allowed a timely reorientation of the diagnosis toward malaria. To assess if the autoantibody immune response was due to autoreactivity or molecular mimicry we isolated 42 autoantigens, targets of malarial autoantibodies. BLAST analysis indicated that 23 of recognized autoantigens were homologous to plasmodial proteins suggesting autoimmune responses directly driven by the plasmodial infection. CONCLUSION: In patients with malaria in whom parasitological tests have not been performed recognition of this new, malaria-related fluorescence pattern on the ANA test is highly suggestive of the diagnosis and triggers immediate, easy confirmation and adapted therapy.

Serum Immunoglobulin Free Light Chain Assessment in IgG4-Related Disease.

Immunoglobulin free light chains are produced in excess during normal antibody synthesis. Their evaluation is commonly used in case of a monoclonal gammopathy. In polyclonal hypergammaglobulinemia related to the Sjögren syndrome or systemic lupus, erythematosus serum free light chain levels are increased and could correlate with disease activity. We show here that the κ (P < 0.0001) and λ (P = 0.0003) free light chains and the κ : λ ratio (P = 0.0049) are increased in sixteen patients with IgG4-related disease when compared to healthy controls. The increase of κ and λ free light chains probably reflects the marked polyclonal B cell activation of the disease. We could not assess in this small cohort of patients a significative correlation of serum free light chain levels and disease activity or extension.