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Zahir Amoura

Publications and source records attributed to Zahir Amoura.

At least 19 recordsLinked to original sources

Affinity-matured B cell responses neutralizing type-I interferons underlie severe viral infections.

Autoantibodies neutralizing type-I interferons (AAN-I-IFNs) emerge as global, common, and strong determinants of a growing number of severe viral diseases. We report that AAN-I-IFNs+ patients with life-threatening COVID-19 pneumonia harbor circulating type-I IFN-specific B cells indistinguishable from patients bearing T cell tolerance defects of genetic origin. This autoimmune response mobilizes a highly diverse and stable circulating B cell response that is detected prior to severe viral infection and acquires high affinity and neutralization potential to type-I IFNs through extended somatic hypermutation. X-ray crystallography and AlphaFold3 structural analysis of hundreds of patient-derived monoclonal antibodies reveals the extended breadth of this response, targeting three major B cell epitopes covering all facets of type-I IFNs. These findings support a model in which a germinal-center-derived memory B cell response directed against type-I IFNs is established before severe viral infection, providing a core mechanism linking T cell tolerance defect to pathogenic AAN-I-IFNs underlying severe viral diseases.

Humans↗

Cardiomyopathy related to antimalarial therapy with illustrative case report.

The antimalarial agents, chloroquine (CQ) and hydroxychloroquine (HCQ) are used in long-term treatment of connective tissue diseases and dermatological disorders and are generally regarded as safe. We present one case of cardiotoxicity in a 59-year-old woman treated with antimalarials during 13 years for a discoid lupus erythematosus. She progressively developed conduction disturbances and congestive heart failure (CHF). When the diagnosis of antimalarials toxicity was suspected, CQ was withdrawn. However, heart transplantation had to be performed in the following 4 months for severe CHF. Indeed, rare but severe cardiotoxicity may develop following prolonged use of antimalarials with both conduction disturbances (45 patients) and CHF (25 patients). These cardiac toxic effects have been reported with CQ and less frequently with HCQ use alone. Diagnoses are often delayed since the toxicity of the drug might be misattributed to other factors in these patients. The endomyocardial biopsy, or in some cases the muscle biopsy, are essential to confirm the antimalarials toxicity. Antimalarials have been stopped in 12 cases of CHF, leading to improvement in 8 cases (within 3 months to 5 years) and to deaths or to heart transplantation in 4 cases (within 1 week to 3 months). In the latter cases, as in our patient, the lack of improvement may have been explained by the severity of the cardiomyopathy at diagnosis and the short delay since withdrawal. As a consequence, the potential for reversibility and the severity in undiagnosed cases of these toxic cardiomyopathies emphasize the importance of recognizing early signs of toxicity in order to withdraw antimalarials before the occurrence of life-threatening CHF.

Antimalarials↗

Shared blood and muscle CD8+ T-cell expansions in inclusion body myositis.

Inclusion body myositis (IBM) is the most frequent inflammatory myopathy over the age of fifty. Pathological findings suggest that two processes may contribute to IBM pathogenesis: a primary degenerative process affecting muscle fibre and/or an autoimmune process mediated by major histocompatibility complex (MHC) class-I-restricted cytotoxic CD8+ T cells. Previous studies have demonstrated that muscle-infiltrating CD8+ T cells in IBM display restricted expression of T-cell receptor (TCR)-BV families or evidenced oligoclonal T-cell expansions. This study was performed to investigate whether blood T cells similarly exhibit clonal expansions due to the recirculation of muscle-infiltrating T cells in the periphery. For this, we studied the T-cell repertoire of 17 IBM patients by complementarity-determining-region (CDR) 3 length distribution (immunoscope) analysis of TCR-B transcripts. Mean age was 68 years (range 53-88) and mean duration of the disease was 6.5 years (2-20). Oligoclonal T-cell expansions were observed in the blood of IBM patients. The quantitative average perturbation D index was significantly increased in IBM patients [D = 13.7% +/- 1.2%, mean +/- standard error of measurement (SEM)] as compared with 17 age-matched controls suffering from connective tissue diseases not associated with T-cell repertoire perturbation, that is, dermatomyositis (DM) and systemic sclerosis (9.3 +/- 0.6%, P < 0.005). Nevertheless, there was no correlation between the level of blood perturbation and muscle inflammation. Sorting experiments showed that these perturbations were due to oligoclonal expansions of CD8+ T cells. In the three IBM patients analysed, we could relate the blood expansions to T-cell clones also found in muscle. The clonally expanded blood T cells dramatically responded to interleukin-2 (IL-2) in vitro, suggesting that they had been primed in vivo, presumably in response to yet unknown muscle auto-antigens. Together, our results indicate that clonally expanded muscle-infiltrating CD8+ T cells re-circulate in the blood and support the concept of a CD8+ T-cell-mediated autoimmune component in IBM, similarly to what is observed in polymyositis (PM).

Aged↗

The immune paradox of sarcoidosis and regulatory T cells.

Sarcoidosis is characterized by extensive local inflammation (granuloma, cytokine secretion) associated with anergy (poor response to antigens in vitro and in vivo). We postulated that this paradoxical situation would correspond to a disequilibrium between effector and regulatory T lymphocytes (T reg cells). We show that CD4+CD25(bright)FoxP3+ cells accumulate at the periphery of sarcoid granulomas, in bronchoalveolar lavage fluid, and in peripheral blood of patients with active disease. These cells exhibited powerful antiproliferative activity, yet did not completely inhibit TNF-alpha production. Sarcoidosis is therefore associated with a global T reg cell subset amplification whose activity would be insufficient to control local inflammation. At the same time, peripheral T reg cells exert powerful antiproliferative activity that may account for the state of anergy. Altogether, these findings advance our conceptual understanding of immune regulation in a way that resolves the immune paradox of sarcoidosis and permit us to envisage a profound clinical impact of T reg cell manipulation on immunity.

Adult↗

Pulmonary arterial hypertension is a major mortality factor in diffuse systemic sclerosis, independent of interstitial lung disease.

OBJECTIVE: To determine whether pulmonary arterial hypertension (PAH) is a prognostic factor for mortality in diffuse cutaneous systemic sclerosis (dcSSc), independent of interstitial lung disease (ILD). METHODS: ILD was diagnosed by high-resolution computed tomography and PAH (pulmonary arterial systolic pressure [PASP] > or =45 mm Hg) by echocardiography. All patients with ILD underwent testing for total lung capacity (TLC), forced vital capacity (FVC), and diffusing capacity for carbon monoxide. RESULTS: Eighty-six patients with dcSSc (mean age at diagnosis 44.5 years) were followed up for a median of 72.5 months. ILD was found in 52 patients (60%) and PAH in 18 (21%). ILD was associated with PAH in 15 patients. Seventeen patients died (19.8%), 9 of whom had PAH (P = 0.001) and 10 of whom had ILD (P = 0.99). By multivariate analysis, age at SSc diagnosis and PAH were the only independent predictors of death (hazard ratio [HR] 1.057, 95% confidence interval [95% CI] 1.009-1.109, P = 0.020 and HR 4.09, 95% CI 1.47-11.5, P = 0.007, respectively). Mean TLC and mean FVC were similar in ILD patients with and those without PAH (P = 0.71 and P = 0.40, respectively). Among ILD patients, age at SSc diagnosis and PAH were again the sole predictors of death (HR 1.073, 95% CI 1.003-1.149, P = 0.042 and HR 5.07, 95% CI 1.09-23.8, P = 0.038, respectively). Twenty ILD patients received at least 6 monthly pulses of intravenous cyclophosphamide (CYC). In CYC-treated patients with PAH (n = 8), PASP increased significantly during the CYC regimen (mean +/- SD 55 +/- 14.5 mm Hg; P = 0.015 versus baseline), while TLC remained stable during the same period. CONCLUSION: These results indicate that, independent of ILD, PAH is a major prognostic factor for survival in dcSSc.

Adult↗

Low blood concentration of hydroxychloroquine is a marker for and predictor of disease exacerbations in patients with systemic lupus erythematosus.

OBJECTIVE: To study the possible relationship between whole-blood hydroxychloroquine (HCQ) concentrations and clinical efficacy of HCQ in patients with systemic lupus erythematosus (SLE). METHODS: Whole-blood HCQ concentrations were measured, under blinded conditions, in 143 unselected patients with SLE who had been receiving HCQ 400 mg daily for at least 6 months. The relationship of these concentrations to current disease activity and to subsequent exacerbations during 6 months of followup was investigated. RESULTS: At baseline, 23 patients had active disease (mean +/- SD SLE Disease Activity Index 12.4 +/- 7.5). The mean whole-blood HCQ concentration in this group was significantly lower than that in the 120 patients with inactive disease (694 +/- 448 ng/ml versus 1,079 +/- 526 ng/ml; P = 0.001). Among the 120 patients who had inactive disease at baseline, the mean HCQ concentration at baseline in the 14 (12%) who had disease exacerbations during followup was significantly lower than that in the patients whose disease remained inactive. Multivariate logistic regression showed that the HCQ concentration was the only predictor of exacerbation (odds ratio 0.4 [95% confidence interval 0.18-0.85], P = 0.01). Receiver operating characteristic curve analysis showed that a whole-blood HCQ concentration cutoff of 1,000 ng/ml had a negative predictive value of 96% for exacerbation during followup. CONCLUSION: Low whole-blood HCQ concentrations are associated with SLE disease activity and are a strong predictor of disease exacerbation. Regular drug assaying and individual tailoring of treatment might help to improve the efficacy of HCQ treatment in patients with SLE.

Adult↗

Variability in the efficacy of interferon-alpha in Erdheim-Chester disease by patient and site of involvement: results in eight patients.

OBJECTIVE: Erdheim-Chester disease (ECD) is a rare, non-Langerhans form of histiocytosis of unknown origin, characterized by infiltration of tissues by spumous histiocytes. ECD features heterogeneous systemic manifestations, and the general prognosis remains poor despite various treatment options. METHODS: We treated 8 patients with multisystemic ECD with subcutaneous interferon-alpha (IFNalpha) at a dosage of 3-9 x 10(6) units 3 times weekly, for a median duration of 23 months (range 1-46 months). RESULTS: Treatment was generally well tolerated, and side effects remained limited to fever following injections. Treatment was discontinued in 1 patient, because of severe depression. During treatment, some manifestations of ECD disappeared (i.e., xanthelasma, exophthalmos, papilledema, and intracranial hypertension). The efficacy of IFNalpha on cardiovascular ECD was variable, however. Treatment resulted in partial regression of "coated aorta" in some cases and clear failure in others; 2 patients died. The level of C-reactive protein diminished sharply in 5 patients. CONCLUSION: IFNalpha might be a valuable first-line therapy for prolonged treatment of ECD. However, the efficacy of IFNalpha varies among patients and according to the sites of disease involvement, and symptoms may fail to respond to treatment, especially in patients with severe multisystemic forms of ECD with central nervous system and cardiovascular involvement.

Adolescent↗

[New therapeutic approaches to autoimmune diseases].

Over the past decade, new biological therapies have been developed to treat systemic autoimmune diseases. These new treatments, which target various steps of the immune response, include: B lymphocyte (BL) inhibitors, such as anti-CD20 monoclonal antibodies, BlyS antagonists, and tolerogens that inhibit specific BLs that produce pathogenic antibodies; inhibitors of costimulation between antigen-presenting cells and T lymphocytes (TL), such as monoclonal antibodies against CD40 ligand and CTLA4-Ig (abatecept); TL antagonists, which can inhibit proliferation of autoreactive T cells; cytokine antagonists; chemokine and adhesin antagonists, which inhibit trafficking of immunocompetent cells to target organs. These new approaches are based on a deeper understanding of the autoimmune response.

Antibodies, Blocking↗

Characteristics and long-term outcome of 15 episodes of systemic lupus erythematosus-associated hemophagocytic syndrome.

Reactive hemophagocytic syndrome (HS) occurs mainly in the setting of serious infections and lymphomas. HS can occur in the course of 2 active systemic diseases, without simultaneous infection: adult Still disease and systemic lupus erythematosus (SLE). Observations of specific lupus-associated HS are rare, and the long-term outcome of these patients with active SLE is unknown. We retrospectively studied 15 episodes of SLE-associated HS in 12 patients (10 women, 2 men) and noted the long-term outcome. HS occurred at a mean age of 25 years. All patients were febrile with >or=2 cytopenias, and bone marrow aspiration indicated hemophagocytosis. HS revealed SLE in 9 patients and recurred in 3. The main features of SLE-associated HS were a low frequency of hepatosplenomegaly, a high frequency of heart involvement (5 pericarditis, 4 myocarditis requiring transfer to intensive care unit), and a low C-reactive protein level (mean, 15 mg/L). Cutaneous-mucous symptoms of SLE, arthritis, and nephritis were present respectively in 8 (53%), 6 (40%), and 4 (27%) episodes, but symptoms of SLE were absent in 4 episodes at admission. All patients had anti-nuclear antibodies when the HS occurred. Anti-double-stranded DNA antibodies were present in 12 episodes. Treatment was steroids in 14 cases but cyclophosphamide was the only treatment able to control HS in 2 cases. All the cases of SLE-associated HS were controlled by the immunosuppressive regimen. Intravenous immunoglobulins seemed poorly effective. No infectious agent was found. Clinical presentations of the 23 patients with SLE-associated HS described in the literature were reviewed and were similar to those of the current series. The mean follow-up was 88 months (range, 7-240 mo). One patient died at 15 months (sepsis). Among the 5 patients with a follow-up >8 years, 4 always had active disease. During the follow-up of SLE, immunosuppressive drugs were added in 8 patients (cyclophosphamide in 7, azathioprine in 3, mycophenolate mofetil in 2) with significant adverse drug reactions. In the long-term, SLE-associated HS seems to define a severe SLE form with frequent flares, possible HS recurrences, and the need for prolonged immunosuppression.

Adolescent↗

High-dose chemotherapy followed by autologous hematopoietic stem cell transplantation for adult histiocytic disorders with central nervous system involvement.

We postulated that high-dose chemotherapy (HDC) followed by peripheral autologous hematopoietic stem cell transplantation might help to control refractory central nervous system (CNS) histiocytic disorders. Six patients with histiocytic CNS involvement were treated in this way. Two patients achieved non-active disease status, although one relapsed at 84 months. Two patients had regressive disease, one of whom progressed at 21 months. One patient had progressive disease at 14 months. One patient had extra-CNS progression but CNS regression. After a median follow-up of 22.4 months, only one of the six patients still has non-active disease. Treatment was effective on craniofacial and space-occupying brainstem lesions, and was ineffective on neurodegenerative lesions.

Adult↗

Bone involvement in Erdheim-Chester disease: imaging findings including periostitis and partial epiphyseal involvement.

PURPOSE: To retrospectively review the bone findings at radiography, scintigraphy, computed tomography (CT), and magnetic resonance (MR) imaging in 11 patients with immunohistochemical and histologic proof of Erdheim-Chester disease. MATERIALS AND METHODS: This study was designed as a retrospective review; approval of the institutional review board and patient consent were not required for this type of study. Eleven patients (eight men and three women; mean age, 49 years; range, 17-68 years) with Erdheim-Chester disease underwent conventional radiography of the skeleton and bone scintigraphy. Two patients underwent CT of the femora and 10 underwent CT of the skull. Eight patients underwent MR imaging. Conventional radiographs, bone scintigrams, CT scans, and MR images were reviewed in consensus by four musculoskeletal radiologists. RESULTS: All 11 patients had involvement of the long bones and normal axial skeleton, hands, and feet. Bilateral and symmetric osteosclerosis of the diaphysis of the long bones was present in 52 (26 pairs) (98%) of the 53 bone lesions visible on conventional radiographs. Osteosclerosis was heterogeneous in 65% of the patients and homogeneous in 35%. Diaphysis was involved in 100% and metaphysis in 44 (83%) lesions. Partial epiphyseal involvement sparing the subchondral bone was present in 24 (45%) lesions. Periostitis was seen in 35 (66%) and endosteitis in 50 (94%) of the 53 long bones involved. Bone scintigraphy depicted tracer uptake in all bone lesions visible on radiographs. Skull and face bone lesions were present in two patients. MR imaging depicted a replacement of the normal fatty bone marrow by heterogeneous signal intensity on T1- and T2-weighted spin-echo images. Lesion extent, epiphyseal involvement, and periostitis were clearly depicted at MR imaging. CONCLUSION: This series provides a detailed description of bone involvement in Erdheim-Chester disease. Periostitis and partial epiphyseal involvement of the long bones are also features of this disease. (c) RSNA, 2005.

Adolescent↗

Global natural regulatory T cell depletion in active systemic lupus erythematosus.

The immune defect that could account for the multisystemic involvement that characterizes systemic lupus erythematosus (SLE) remains unknown. We hypothesized that iterative disease flares correspond to a recurrent defect in the peripheral immune suppression exerted by naturally occurring T regulatory cells (Tregs). Surprisingly, Tregs isolated from lupus patients show the same phenotypic and functional characteristics as corresponding cells found in healthy controls. A decrease in the proportion of circulating Tregs among other CD4+ T cells is nevertheless evidenced in active patients when this group is compared with healthy controls (0.57 +/- 0.24%, n = 45 vs 1.29 +/- 0.38%, n = 82, p < 0.0001) or with inactive patients (1.22 +/- 0.67%, n = 62, p < 0.0001). In contrast, the proportion of Tregs in other systemic autoimmune diseases such as primary Sjögren syndrome and inflammatory myopathy does not significantly differ from controls' values (1.15 +/- 0.46%, n = 21, p = 0.09 and 1.16 +/- 0.44%, n = 16, p = 0.43, respectively). Lupus Tregs do not accumulate in either the lymph nodes or the diseased kidneys and are not killed by a circulating soluble factor, but demonstrate in vitro a heightened sensitivity to Fas-induced apoptosis. Finally, we show that the extent of Treg depletion correlates with the clinical severity of the flare. SLE flares are therefore associated with a global Treg depletion and not with a phenomenon of tissue redistribution. In summary, we suggest that the physiopathology of SLE could be tied to a defect in the homeostatic control of the Treg subpopulation.

Adolescent↗

Repertoire, diversity, and differentiation of specific CD8 T cells are associated with immune protection against human cytomegalovirus disease.

To determine the correlates of immune recovery from active human CMV (HCMV) disease, we compared the antigenic repertoire, diversity, magnitude, and differentiation of HCMV-specific CD8+ T cells in HIV-HCMV coinfected subjects with no, cured, or active HCMV disease and in healthy HIV-negative HCMV-positive controls. ELISPOT-IFN-gamma assays using peptide pools spanning the pp65 and immediate early 1 (IE1) HCMV proteins showed that HCMV-specific CD8+ T cells had a significantly broader antigenic repertoire and greater diversity in HIV-positive patients controlling HCMV replication than in those with active HCMV disease, but the magnitude of the CD8 T cell response did not differ between the different groups. HCMV-specific T cells mainly were focused against IE1 during the short-term recovery from retinitis, and switched toward pp65 during long-term recovery. HCMV-specific T cells displaying an "early" (CD8+CD27+CD28+) and "intermediate" (CD8+CD27-CD28+) differentiation phenotype were increased significantly during long-term recovery compared with other HIV-positive patients and were nearly undetectable during active HCMV disease. HCMV-specific T cells with a "late" (CD8+CD27-28-) differentiation phenotype predominated in all cases. Therefore, restoration of immune protection against HCMV after active HCMV disease in immunodeficient individuals is associated with enlarged repertoire and diversity, and with early differentiation of virus-specific CD8+ T cells, thus defining immune correlates of protection against diseases caused by persistent viruses.

Acquired Immunodeficiency Syndrome↗

[Behçet's disease].

Behçet's disease is a vasculitis of unknown origine. Mucocutaneous manifestations are necessary for diagnosis. Ocular and neurological involvements can lead to severe impairment. Arterial involvement may be lethal. Treatment is only symptomatic using steroids, colchicine and antiaggregant therapy. Immunosuppressive drugs are generally given for severe manifestations resistant to conventional therapy. Alpha interferon and infliximab are interesting in case of failure or relapses despite treatment. As in all chronic diseases, education and good observance are needed to improve prognosis.

Behcet Syndrome↗

Anti-SSA/Ro antibodies and the heart: more than complete congenital heart block? A review of electrocardiographic and myocardial abnormalities and of treatment options.

Apart from complete and incomplete congenital heart block (CHB), new cardiac manifestations related to anti-SSA/Ro antibodies have been reported in children born to mothers bearing these antibodies. These manifestations include transient fetal first-degree heart block, prolongation of corrected QT (QTc) interval, sinus bradycardia, late-onset cardiomyopathy, endocardial fibroelastosis and cardiac malformations. Anti-SSA/Ro antibodies are not considered pathogenic to the adult heart, but a prolongation of the QTc interval has recently been reported in adult patients and is still a matter of debate. Treatment of CHB is not well established and needs to be assessed carefully. The risks and benefits of prenatal fluorinated steroids are discussed.

Adult↗

Association of the R92Q TNFRSF1A mutation and extracranial deep vein thrombosis in patients with Behçet's disease.

OBJECTIVE: Behçet's disease is a chronic, relapsing, multisystemic inflammatory disorder characterized by recurrent oral and genital ulcers and by ocular, articular, vascular, and central nervous system involvement. The tumor necrosis factor alpha (TNFalpha) pathway is likely involved in the pathophysiology of Behçet's disease. One of the 2 TNFalpha receptors is TNF receptor superfamily 1A (TNFRSF1A). We searched for R92Q TNFRSF1A mutations in patients with Behçet's disease. METHODS: A search for TNFRSF1A mutations was performed by polymerase chain reaction amplification of the TNFRSF1A gene, followed by denaturing high-performance liquid chromatography scanning. RESULTS: Among the 74 unrelated European patients with Behçet's disease, 5 (6.8%) carried the R92Q TNFRSF1A mutation. The frequency of the R92Q mutation in patients with Behçet's disease was significantly higher than that in controls (P = 0.006 by Fisher's exact test). Deep vein thrombosis was significantly associated with the R92Q mutation (P = 0.001 [with Bonferroni adjustment for multiple comparisons]). Among the 30 patients with thrombosis, 10 had cerebral thrombophlebitis. None of these patients had the R92Q mutation. Among the 20 patients with Behçet's disease who had extracranial deep vein thrombosis, 6 had the R92Q mutation, whereas 14 did not (P < 0.0001) CONCLUSION: The R92Q mutation in patients with Behçet's disease is associated with an increased risk of extracranial venous thrombosis. This new finding may help in understanding the complex prothrombotic state in patients with Behçet's disease.

Behcet Syndrome↗

Tumor antigen markers for the detection of solid cancers in inflammatory myopathies.

Dermatomyositis and polymyositis patients have an increased risk of developing cancers. We have assessed the diagnostic values of serum tumor markers for the detection of solid cancer in dermatomyositis/polymyositis patients. Serum carcinoembryonic antigen, CA15-3, CA19-9, and CA125 were assayed by immunoradiometric methods in 102 dermatomyositis/polymyositis patients. All the patients had complete physical examination, chest X-ray, echocardiogram, gastrointestinal tract endoscopic explorations, thoracoabdomino-pelvic computed tomography scan, and all women had gynecologic examination and mammogram. Exclusion criteria for study were childhood dermatomyositis, inclusion body myositis, myositis associated with a connective tissue disease, prior history of cancer, and the presence of benign conditions known to elevate serum tumor markers. After a median follow-up of 59 months, 10 (9.8%) patients had a solid cancer. Initial elevation of CA125 was associated with an increased risk of developing solid cancer [P = 0.0001 by Fisher's exact test; odds ratio (OR), 29.7; 95% confidence interval (95% CI), 8.2-106.6]. For CA19-9, there was a trend towards a significant association (P = 00.7; OR, 4.5; 95% CI, 1-18.7, respectively). Diagnostic values of elevated CA125 and CA19-9 at screening increased when the study analysis was restricted to patients who developed a cancer within 1 year (P < 0.0001 and P = 0.018, respectively) or to patients without interstitial lung disease (P = 0.00001; OR, 133; 95% CI, 6.5-2733 and P = 0.027; OR, 9; 95% CI, 1.5-53, respectively). Individual comparisons of the baseline and the second CA125 value showed that three of the eight patients with cancers versus 3 of the 76 patients without, displayed an increase of their CA125 level (P = 0.01 by Fisher's exact test). We conclude that CA125 and CA19-9 assessment could be useful markers of the risk of developing tumors for patients with dermatomyositis and polymyositis and should therefore be included in the search for cancer in dermatomyositis/polymyositis patients, especially for patients without interstitial lung disease.

Adult↗