Antineutrophil Cytoplasmic Antibody Induction due to Infection: A Patient with Infective Endocarditis and Chronic Hepatitis C

New-onset microscopic polyangiitis temporally associated with severe COVID-19 infection: A case report

The coronavirus disease 2019 has been demonstrated to be a trigger for multiple immune-mediated diseases, such as antineutrophil cytoplasmic antibody-associated vasculitis. Associated vasculitis consists of rare autoimmune disorders that predominantly affect small vessels, leading to endothelial injury and tissue damage. We present a case of a newly diagnosed microscopic polyangiitis temporally associated with coronavirus disease 2019 infection in a previously healthy woman and a literature review. A 66-year-old female presented to the Emergency Room with fever, edema on her legs, productive cough, dyspnea, and hemoptysis. A chest computerized tomography scan revealed bilateral diffuse alveolar opacities with the appearance of diffuse alveolar hemorrhage. Blood analysis revealed a moderate normocytic, normochromic anemia with a hemoglobin of 6.6 g/dL, platelet count of 347 k/dL, leucocytes of 12,000/dL, a creatinine of 3.91 mg/dL (basal Cr: 0.9 mg/dL), and a Blood Urine Nnitrogen of 78 mg/dL. A urine sediment demonstrated glomerular hematuria, with mixed shapes of red blood cells. She was admitted to the intensive care unit and a bedside bronchoscopy revealed progressive bleeding with a bronchioalveolar lavage positive for diffuse alveolar hemorrhage. Given the critical involvement of the lungs and kidney function, the diagnostic approach revealed a positive p-anti-neutrophil cytoplasmic antibody on immunofluorescence and an anti-MPO (myeloperoxidase) level of 124.6 IU/mL. A renal biopsy demonstrated pauciimmune focal and segmental glomerulosclerosis. A diagnosis of microscopic polyangiitis triggered by severe acute respiratory syndrome coronavirus 2 infection was made, and immediate treatment with pulse-dose steroids and cyclophosphamide was initiated. The patient needed renal replacement therapy and was discharged for follow-up with nephrology and rheumatology services. The diagnostic approach of associated vasculitis can be more challenging in the coronavirus disease era. Atypical features in the pulmonary imaging and a rapid deterioration of the renal function should arise the clinical suspicion of the presence of an added condition to the coronavirus disease infection. Autoimmune conditions such as associated vasculitis should be evaluated even in the absence of previous autoimmune history. Prompt diagnosis and treatments must be prioritized to avoid end-organ definite damage. Further, larger and more collaborative studies are needed to confirm the potential role of coronavirus disease 2019 as a trigger of associated vasculitis.

Antineutrophil cytoplasmic antibodies in infective endocarditis: a case report and systematic review of the literature

Infective endocarditis (IE) may be misdiagnosed as ANCA-associated vasculitis (AAV), especially when antineutrophil cytoplasmic antibodies (ANCA) are detected. Distinguishing IE from AAV is crucial to guide therapy. However, little is known about ANCA positivity in IE patients. We present a case report and systematic review of the literature on patients with ANCA-positive IE, aiming to provide a comprehensive overview of this entity and to aid clinicians in their decisions when encountering a similar case. A systematic review of papers on original cases of ANCA-positive IE without a previous diagnosis of AAV was conducted on PubMed in accordance with PRISMA-IPD guidelines. A predefined set of clinical, laboratory, and kidney biopsy findings was extracted for each patient and presented as a narrative and quantitative synthesis. A total of 74 reports describing 181 patients with ANCA-positive IE were included (a total of 182 cases including our own case). ANCA positivity was found in 18-43% of patients with IE. Patients usually presented with subacute IE (73%) and had positive cytoplasmic ANCA-staining or anti-proteinase-3 antibodies (79%). Kidney function was impaired in 72%; kidney biopsy findings were suggestive of immune complexes in 59%, while showing pauci-immune glomerulonephritis in 37%. All were treated with antibiotics; 39% of patients also received immunosuppressants. During follow-up, 69% of patients became ANCA-negative and no diagnosis of systemic vasculitis was reported. This study reviewed the largest series of patients with ANCA-positive IE thus far and shows the overlap in clinical manifestations between IE and AAV. We therefore emphasize that clinicians should be alert to the possibility of an underlying infection when treating a patient with suspected AAV, even when reassured by ANCA positivity. Key Points • This systematic review describes - to our knowledge - the largest series of patients with ANCA-positive infective endocarditis (IE) thus far (N=182), and shows a high degree of overlap in clinical manifestations between IE and ANCA-associated vasculitis (AAV). • ANCA positivity was found in 18-43% of patients with infective endocarditis. Of patients with ANCA-positive IE, the majority (79%) showed cytoplasmic ANCA-staining or anti-PR3-antibodies. We emphasize that clinicians should be alert to the possibility of an underlying infection when treating a patient with suspected AAV, even when reassured by ANCA positivity. • In patients with IE and ANCA-associated symptoms such as acute kidney injury, an important clinical challenge is the initiation of immunosuppressive therapy. All patients with data in this series received antibiotics; 39% also received immunosuppressive therapy. In many of these patients, ANCA-associated symptoms resolved or stabilized after infection was treated. ANCA titers became negative in 69% , and a diagnosis of AAV was made in none of the cases. We therefore recommend that (empiric) antibiotic treatment remains the therapeutic cornerstone for ANCA-positive IE patients, while a watchful wait-and-see approach with respect to immunosuppression is advised.

Antineutrophil cytoplasmic antibodies (ANCA)-positive patient with infective endocarditis and chronic hepatitis B virus: a case report and review of the literature

Background

Antineutrophil cytoplasmic antibodies comprise a family of autoantibodies that are often used as biomarkers for certain forms of small-vessel vasculitis; however, chronic infections tend to induce the production of antineutrophil cytoplasmic antibodies. Infective endocarditis and hepatitis B virus infection have been reported to exhibit antineutrophil cytoplasmic antibody positivity and to mimic antineutrophil cytoplasmic antibody–associated vasculitis, which may lead to misdiagnosis and inappropriate treatment.

Case presentation

We report a case of a 46-year-old Han Chinese man with untreated chronic hepatitis B virus infection who featured proteinase-3 antineutrophil cytoplasmic antibody positivity while hospitalized with infective endocarditis. Cardiac ultrasound echocardiography disclosed mitral and aortic regurgitation with vegetation. On the 15th hospital day, the patient underwent mitral and aortic valve replacement and was then treated with antibiotics for more than 1 month. On the 57th hospital day, the patient was discharged. His urinary abnormalities and renal function were gradually recovering. Four months after being discharged, his proteinase-3 antineutrophil cytoplasmic antibody levels had returned to the normal range.

Conclusions

The findings in this study update and expand current understanding of antineutrophil cytoplasmic antibody positivity in patients with both infective endocarditis and hepatitis B virus. Treatment (including surgery, antibiotics, corticosteroids and/or cyclophosphamide, antiviral agents, and even plasma exchange) is challenging when several diseases are combined. Renal biopsy is suggested if the patient’s condition allows. Antineutrophil cytoplasmic antibody testing should be repeated after therapy, because some cases might require more aggressive treatment.

Bacillus cereus Subacute Native Valve Infective Endocarditis and Its Multiple Complications

Bacillus cereus causing infective endocarditis (IE) in a native valve is an extremely rare event, but it is reported mostly in intravenous drug abusers and other risk factors as immunosuppression, malignancy, and valvular heart disease including prosthetic heart valves. We report a case of B.cereus native mitral valve infective endocarditis in a 58-year-old Sri Lankan male who is not a drug abuser who presented with painless hematuria with reduced urine output. During hospital stay, he developed frequent episodes of brief focal seizures. He had undergone multiple investigations that revealed splenic abscesses, cerebral vasculitis, and glomerular nephritis with positive rheumatoid factor, cytoplasmic antineutrophil cytoplasmic antibody (C-ANCA), and cryoglobulin. The appropriate antibiotic was the prime therapeutic intervention which carried an excellent prognosis. This case highlights an unusual organism in the blood culture that caused IE warranting thorough physical examination and investigations.

Severe Infection in Anti-Glomerular Basement Membrane Disease: A Retrospective Multicenter French Study

In patients presenting with anti-glomerular basement membrane (GBM) disease with advanced isolated kidney involvement, the benefit of intensive therapy remains controversial due to adverse events, particularly infection. We aim to describe the burden of severe infections (SI) (requiring hospitalization or intravenous antibiotics) and identify predictive factors of SI in a large cohort of patients with anti-GBM disease. Among the 201 patients (median [IQR] age, 53 [30–71] years) included, 74 had pulmonary involvement and 127 isolated glomerulonephritis. A total of 161 SI occurred in 116 patients during the first year after diagnosis. These infections occurred during the early stage of care (median [IQR] time, 13 [8–19] days after diagnosis) with mainly pulmonary (45%), catheter-associated bacteremia (22%) and urinary tract (21%) infections. In multivariable analysis, positive ANCA (HR [95% CI] 1.62 [1.07−2.44]; p = 0.02) and age at diagnosis (HR [95% CI] 1.10 [1.00–1.21]; p = 0.047) remained independently associated with SI. Age-adjusted severe infection during the first three months was associated with an increased three-year mortality rate (HR [95% CI] 3.13 [1.24–7.88]; p = 0.01). Thus, SI is a common early complication in anti-GBM disease, particularly in the elderly and those with positive anti-neutrophil cytoplasmic antibodies (ANCA). No significant association was observed between immunosuppressive strategy and occurrence of SI.

Case Report: Patient with Hepatitis C, p-ANCA, and Cryoglobulin Antibodies Presenting with Necrotizing Crescentic p-ANCA Glomerulonephritis

Hepatitis C (HCV) infection has a prevalence of 3 million infected individuals in the United States, according to recent Center for Disease Control reports, and can have various renal manifestations. Cryoglobulins, antibodies that precipitate at colder temperatures in vitro, are a relatively common cause of renal disease in HCV infection. The cryoglobulin proteins can form occlusive aggregates in small glomerular capillary lumina or deposit in other areas of the glomerulus, resulting in hypocomplementemia, proteinuria, hematuria, and renal injury. The typical biopsy pattern is that of membranoproliferative glomerulonephritis (MPGN). There are, however, other HCV-related patterns of glomerular injury. Anti-neutrophil cytoplasmic antibodies (ANCA) are known to exist in HCV-infected patients. In many reported cases, ANCA serologic testing may appear positive due to cross-reactivity of the immune assays; however, the biopsy findings do not support ANCA-associated crescentic glomerulonephritis (GN)/vasculitis as the primary cause of glomerular injury. There are rare reports of microscopic polyangiitis (MPA) p-ANCA vasculitis, in patients with HCV infection. In comparison with the MPGN pattern of cryoglobulinemic glomerular injury, biopsies from these HCV-infected patients with concomitant MPA revealed a crescentic GN, associated with normal serum complement levels. We present a case of HCV-associated glomerular disease with the surprising biopsy finding of necrotizing and crescentic p-ANCA GN, with a background, low-grade mesangial immune complex GN. Thus, p-ANCA disease should also be considered in HCV-infected patients, in addition to the more typical lesions of MPGN or cryoglobulinemic GN.

Multiorgan Involvement Confounding the Diagnosis of Bartonella henselae Infective Endocarditis in Children With Congenital Heart Disease

Two children with congenital heart disease status post surgical correction presented with prolonged constitutional symptoms, hepatosplenomegaly and pancytopenia. Concern for malignancy prompted bone marrow biopsies that were without evidence thereof. In case 1, echocardiography identified a multilobulated vegetation on the conduit valve. In case 2, transthoracic, transesophageal and intracardiac echocardiography were performed and were without evidence of cardiac vegetations; however, pulmonic emboli raised concern for infective endocarditis. Both patients underwent surgical resection of the infected material and had histopathologic evidence of infective endocarditis. Further diagnostics identified elevated cytoplasmic antineutrophil cytoplasmic antibodies and antiproteinase 3 antibodies in addition to acute kidney injury with crescentic glomerulonephritis on renal biopsy. Serologic evidence of infection with Bartonella henselae was observed in both patients. These 2 cases highlight the potential multiorgan involvement that may confound the diagnosis of culture-negative infective endocarditis caused by B. henselae.