Deficiency of the CD155-CD96 immune checkpoint controls IL-9 production in giant cell arteritis

Loss of function of inhibitory immune checkpoints, unleashing pathogenic immune responses, is a potential risk factor for autoimmune disease. Here, we report that patients with the autoimmune vasculitis giant cell arteritis (GCA) have a defective CD155-CD96 immune checkpoint. Macrophages from patients with GCA retain the checkpoint ligand CD155 in the endoplasmic reticulum (ER) and fail to bring it to the cell surface. CD155low antigen-presenting cells induce expansion of CD4+CD96+ T cells, which become tissue invasive, accumulate in the blood vessel wall, and release the effector cytokine interleukin-9 (IL-9). In a humanized mouse model of GCA, recombinant human IL-9 causes vessel wall destruction, whereas anti-IL-9 antibodies efficiently suppress innate and adaptive immunity in the vasculitic lesions. Thus, defective surface translocation of CD155 creates antigen-presenting cells that deviate T cell differentiation toward Th9 lineage commitment and results in the expansion of vasculitogenic effector T cells.

Testing anti-neutrophil cytoplasmic antibodies (ANCA): analysis of the European EASI survey on the daily practice of the French laboratories

Anti-neutrophil cytoplasmic antibodies (ANCA) are mainly searched for the diagnosis of autoimmune vasculitis. They may be found also in other conditions with chronic inflammation. Testing ANCA is based on two main technics: indirect immunofluorescence (IFI) and immunochemical technics to identify the antigenic specificity of the autoantibodies. There is heterogeneity among the laboratories' daily practice. An international group called EASI (European autoimmunity standardisation initiative), composed of 15 countries, comprising France, works to harmonize the practices of the biological diagnosis of the autoimmune diseases. It elaborated a survey consisting of 54 questions related to the analytic parameters of the technics, the algorithms for their use and their biological interpretation; and submitted it to European laboratories. We propose an analysis of the answers obtained from 36 French laboratories specialized in autoimmunity. We compare them to the ones obtained from the other countries and discussed them according to the international recommendations. The analysis reveals a predominant use of IFI as a first step with variable strategies for the identification of the antigenic specificity of the autoantibodies. Overall, the practices are chiefly conformed to the recommendations for the diagnosis of vasculitis, but they are less consensual when the ANCA are performed in other clinical situations.

Elucidating the Intriguing Association Between Systemic Lupus Erythematosus and Cardiovascular Disease

Systemic lupus erythematosus (SLE) patients have demonstrated a higher risk of developing cardiovascular disease (CVD), resulting in it being one of the leading causes of death in SLE patients. SLE itself acts as a sole risk factor influencing the prevalence and progression of CVD. However, conventional risk factors, such as age, hypertension, smoking, and obesity, play a crucial role as well. Therefore, this systematic review attempts to unravel the association of CVD in SLE patients while evaluating the role of conventional risk factors. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to search the PubMed database starting from March 2021 systematically. Original studies that evaluated the prevalence and progression of CVD in SLE patients were extracted by two reviewers independently. Quality in Prognostic Studies (QUIPS) tool was used to assess the risk of bias. Most studies have a moderate to low risk of bias. Among 3,653 studies identified by our search, 10 studies were included in the review. Strong epidemiologic evidence of SLE patients having an increased relative risk of CVD compared to controls was found. Traditional CVD risk factors, such as age, hypertension, obesity, and smoking, influence the prevalence of CVD among SLE patients. Several SLE-specific factors such disease activity, duration, and certain medications also acted as influencing factors. However, the relative risk of CVD was still higher in SLE patients after adjustment of certain risk factors. One study found that the odds of having a Coronary Artery Calcification (CAC) score greater than zero in women with SLE aged less than or equal to 45 years was 12.6 times higher than women in the Coronary Artery Risk Development in Young Adults (CARDIA) cohort (95% CI 5.2 to 30.7) (participants of CARDIA cohort acted as control). This finding was made after age, hypertension, total cholesterol levels, and aspirin use were adjusted, and the study was restricted to women. Although conventional risk factors increase CVD prevalence, SLE itself also dramatically increases the prevalence of CVD. Therefore, we recommend that SLE should be treated as a "CVD risk equivalent." SLE patients should be managed more extensively with greater emphasis given to cardiac health for better clinical outcomes.

Toe Amputation After Minor Surgery in a Patient with Behçet's Disease: A Case Report

Behçet's disease is a systemic autoimmune vasculitis. Although various clinical findings can be observed depending on the pathologic features caused by the blood vessels involved, the classic triad of the disease includes oral aphthae, genital ulcers, and uveitis. Although complications involving the aorta or the vena cava inferior can prove fatal, thrombophlebitis in the superficial veins of the lower extremities are more commonly observed. Some patients can remain asymptomatic for a long period after the diagnosis. In patients with positive pathergy test findings, trauma can trigger the inflammatory cascade. This case report presents a patient with vasculitis that occurred subsequent to minor surgery and led to amputation of the great toe in a female patient with a 14-year old history of Behçet's disease.

Eosinophilic Granulomatosis With Polyangiitis Presentation After Nandrolone Withdrawal

A 41-year-old man was admitted to the Emergency Department with bilateral numbness in lower extremities and left femoral palsy. He also reported constitutional symptoms, vomiting and non-bloody diarrhoea for the last several months. He had a previous history of eosinophilic asthma with erratic follow-up. During admission, eosinophil count was 66% of white blood cells. Sural nerve biopsy revealed vasculitis with eosinophilic infiltration. Further evaluations consisted of colonoscopy and nasal endoscopy that confirmed eosinophil infiltrates on colonic ulcers and nasal polypi. The patient was started on systemic corticosteroids and cyclophosphamide. Among his personal records, he had been taking nandrolone decanoate without medical prescription, and had withdrawn a few years before the first asthma exacerbation.

An Aggressive Case of Cryoglobulinemia and Membranoproliferative Glomerulonephritis: A Case Report

This case report describes a 66-year-old female with membranoproliferative glomerulonephritis (MPGN) with pulmonary involvement presumed secondary to Hepatitis C virus (HCV)-associated with mixed cryoglobulinemia. In this condition, pulmonary involvement is uncommon, and aggressive lung involvement can be associated with poor outcomes. Within eight weeks, the patient was hospitalized twice with acute pulmonary presentations and presented at a third hospitalization with dyspnea, chest pain, abdominal pain, and edema. Imaging revealed persistent and historically evolving lung consolidation, as well as a renal biopsy showing MPGN associated with mixed cryoglobulinemia. A lung biopsy revealed inflammation. Bronchoalveolar lavage did not show hemosiderin-laden macrophages and did not grow infectious agents. Serology revealed negative ANCAs and rheumatoid factor positive at 476 IU/ml (upper limit normal 14 IU/ml). Qualitative cryoglobulins were positive at 2 %ppt (reference range: negative %ppt) and Type II mixed cryoglobulinemia with IgM kappa plus polyclonal IgG. The treatment involved steroids and rituximab. The patient's clinical status deteriorated, and she elected to change her resuscitation status to comfort care measures. This case emphasizes that cryoglobulinemia can present with aggressive manifestations on a wide spectrum. Pulmonary manifestations are rare and were evident in this case (although without clear evidence of diffuse alveolar hemorrhage) and led to a complicated disease course and an unfavorable outcome. Overall, this case underscores the complexity of mixed cryoglobulinemia presentations and the challenges of managing severe cases with multi-organ involvement.

Rheumatoid Vasculitis Involving Gastrointestinal Tract Pre-dating Rheumatoid Arthritis: A Case Study and Literature Review

Rheumatoid vasculitis (RV) constitutes a rare but serious complication of rheumatoid arthritis (RA), characterized by the inflammation of small and medium-sized blood vessels. We present a case of a 34-year-old male with chronic alcoholism who presented with epigastric pain, hematemesis, purpuric rashes, and multiple joint swelling and pain, without prior RA diagnosis. Abdominal angiography was unremarkable, ruling out Polyarteritis Nodosa (PAN) and Mallory Weiss tear. Upper GI endoscopy revealed erosive gastroduodenitis, and biopsies confirmed small vessel leukocytoclastic vasculitis with fibrinoid necrosis, initially raising suspicion of Henoch-Schonlein Purpura (HSP). However, positive rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP) antibody, elevated inflammatory markers (erythrocyte sedimentation rate (ESR), C-reactive protein (CRP)), and negative immunoassay tests led to the diagnosis of RV. Treatment with intravenous hydrocortisone led to rapid improvement, and the patient is now being monitored on an outpatient basis with progressive recovery. This case underscores the unusual presentation of gastrointestinal involvement in RV. It highlights the importance of considering RV as a primary diagnosis, even in the absence of a prior RA diagnosis. Early recognition and intervention are critical for managing complications, emphasizing the need for a high index of suspicion in rheumatic diseases' unusual presentations.

Unique Presentation of Microscopic Polyangiitis: Hearing and Vision Loss, Dysphagia, and Renal Dysfunction

Microscopic polyangiitis (MPA) is an autoimmune small-vessel vasculitis often positive for perinuclear anti-neutrophil cytoplasmic antibody (p-ANCA), or anti-myeloperoxidase (MPO), that classically affects the lungs, kidneys, and skin. Several atypical presentations of MPA involving other organs have also been reported in the literature. We report a unique case of a patient who presented with rare presentations of MPA: hearing and vision loss, dysphagia, renal dysfunction. Despite the atypical nature of her symptoms, her p-ANCA serology was positive and kidney biopsy was consistent with MPA. Regardless of the bizarre nature of a patient’s symptoms, we highlight the importance of considering MPA as a differential diagnosis in the setting of positive p-ANCA serology.

A Young Female Newly Diagnosed With Takayasu's Arteritis Masquerading As Cerebrovascular Stroke

The condition known as Takayasu's disease or Takayasu's arteritis is a type of vascular inflammation that affects the large and medium arteries. It can lead to a reduction in blood flow to various parts of the body, and it can cause severe complications. Patients with this disease may not have specific symptoms, which can lead to their diagnosis not being confirmed. Takayasu's disease is believed to be a probable cause of stroke in young patients. Although stroke is a common cause of morbidity, it is usually not an initial presentation in Takayasu's disease. In this study, a young female with left-sided hemiparesis was diagnosed with Takayasu's disease after a clinical and angiographic examination.

The Vital Role of Immunohematology in Diagnosing Paroxysmal Cold Hemoglobinuria: A Clinical Case Report

Paroxysmal cold hemoglobinuria (PCH) is a rare autoimmune hemolytic anemia caused by the binding of IgG immunoglobulins to red blood cells at cold temperatures, leading to hemolysis upon rewarming. The Donath-Landsteiner test can show biphasic hemolysis, leading to diagnosis. There is no consensus, but chemoimmunotherapy with or without plasma exchange is commonly employed. We present the case of a 42-year-old male who experienced symptoms of hemolysis after cold exposure in a semi-arid, warm-climate city.

A Rare Presentation of Wegener's Granulomatosis With Perinuclear Antineutrophil Cytoplasmic Antibody Positivity

Wegener's granulomatosis (WG), also termed granulomatosis with polyangiitis, is a vasculitic condition with numerous systemic manifestations. It is mainly a pauci-immune vasculitis which involves small and medium-sized vessels. Herein, we report a case of a 72-year-old female with a background history of type 2 diabetes mellitus and hypertension. She presented to the hospital with recurrent nasal congestion, headache, and intermittent facial pain for two months' duration. At the initial presentation, she was diagnosed with pansinusitis, for which she was treated with antibiotics and was discharged. Two weeks later, she presented with progressively worsening bilateral lower limb numbness and weakness for one week's duration. With serial investigations, she was diagnosed with WG and was treated with intravenous methylprednisolone along with cyclophosphamide, after which she made a significant improvement in her clinical status.

Neuro-Behcet's Disease and Its Association With Cerebral Aneurysms and Subarachnoid Hemorrhage: A Case Report

Behçet's disease is a rare autoimmune condition characterized by systemic vasculitis, an inflammation of blood vessels, with an unknown etiology. It has varied clinical presentations. Herein, we present the case of a 31-year-old male patient with neuro-Behçet disease who presented with subarachnoid hemorrhage and microaneurysms.

A Unique Case of Rapidly Progressive Glomerulonephritis in a Patient With Anti-neutrophil Cytoplasmic Antibody (ANCA)-Positive Vasculitis Presenting With Ocular and Cardiac Manifestations

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAVs) can be divided into three distinct clinical entities. Of the three subgroups, granulomatosis with polyangiitis (GPA) is the most common AAV. We present a 33-year-old Hispanic male with no past medical history who presented to the ER with acute-onset pleuritic chest pain and dyspnea. The patient had chronic sinusitis with occasional epistaxis. Initial lab work was significant for hematuria and proteinuria, as well as worsening acute kidney injury (AKI). A renal biopsy confirmed the presence of rapidly progressive glomerulonephritis (RPGN). Autoimmune panels were significant for PR3-ANCA positivity. The patient's clinical picture was most compatible with that of GPA, given the prominence of upper airway symptoms in the setting of new-onset renal failure with erythrocyturia and proteinuria, as well as pulmonary lesions. Cyclophosphamide-based treatment was initiated, in conjunction with glucocorticoids, mesna, and atovaquone. High suspicion for GPA with RPGN should be considered in the younger population who present with new-onset renal failure and pulmonary lesions to present irreversible kidney injury.