Thoracic Involvement in IgG4-Related Disease.

Immunoglobulin G4-related disease (IgG4-RD) is a systemic fibroinflammatory disorder that has been recognized to involve virtually any organ in the body and typically manifests mass-like lesions (tumefactive). Although initial reports of this disease (autoimmune pancreatitis [AIP]) were described in the Japanese population, it has since been reported worldwide. It is most commonly seen in adults of middle age or older, more often men than women. The pathogenesis of IgG4-RD is largely unknown, but genetic factors, microorganisms, and autoimmunity are thought to play important roles. Serum IgG4 concentration is elevated in the majority of patients with IgG4-RD but is a nonspecific finding. Characteristic histopathologic features include dense lymphoplasmacytic infiltrate, fibrosis (often in storiform pattern), and obliterative phlebitis. Lung involvement in IgG4-RD was first reported in 2004 in two patients with AIP and coexisting interstitial lung disease. Since then, a wide spectrum of intrathoracic involvement has been reported and includes not only parenchymal lung diseases but also pleural, airway, vascular, and mediastinal lesions. Thoracic involvement in IgG4-RD is often found incidentally during the workup of extrathoracic lesions but can sometimes be the presenting abnormality. The diagnosis of IgG4-RD requires correlation of clinical, laboratory, imaging, and histopathologic features. Glucocorticoids are the first-line therapy but other options including B cell depletion are being investigated. IgG4-RD is generally associated with an indolent clinical course and most patients improve with glucocorticoid therapy.

One-Stop Serum Assay Identifies COVID-19 Disease Severity and Vaccination Responses.

SARS-CoV-2 has caused over 100,000,000 cases and almost 2,500,000 deaths globally. Comprehensive assessment of the multifaceted antiviral Ab response is critical for diagnosis, differentiation of severity, and characterization of long-term immunity, especially as COVID-19 vaccines become available. Severe disease is associated with early, massive plasmablast responses. We developed a multiplex immunoassay from serum/plasma of acutely infected and convalescent COVID-19 patients and prepandemic and postpandemic healthy adults. We measured IgA, IgG, and/or IgM against SARS-CoV-2 nucleocapsid (N), spike domain 1 (S1), S1-receptor binding domain (RBD) and S1-N-terminal domain. For diagnosis, the combined [IgA + IgG + IgM] or IgG levels measured for N, S1, and S1-RBD yielded area under the curve values ≥0.90. Virus-specific Ig levels were higher in patients with severe/critical compared with mild/moderate infections. A strong prozone effect was observed in sera from severe/critical patients-a possible source of underestimated Ab concentrations in previous studies. Mild/moderate patients displayed a slower rise and lower peak in anti-N and anti-S1 IgG levels compared with severe/critical patients, but anti-RBD IgG and neutralization responses reached similar levels at 2-4 mo after symptom onset. Measurement of the Ab responses in sera from 18 COVID-19-vaccinated patients revealed specific responses for the S1-RBD Ag and none against the N protein. This highly sensitive, SARS-CoV-2-specific, multiplex immunoassay measures the magnitude, complexity, and kinetics of the Ab response and can distinguish serum Ab responses from natural SARS-CoV-2 infections (mild or severe) and mRNA COVID-19 vaccines.

Elevated SARS-CoV-2 Antibodies Distinguish Severe Disease in Early COVID-19 Infection.

BACKGROUND: SARS-CoV-2 has caused over 36,000,000 cases and 1,000,000 deaths globally. Comprehensive assessment of the multifaceted anti-viral antibody response is critical for diagnosis, differentiation of severe disease, and characterization of long-term immunity. Initial observations suggest that severe disease is associated with higher antibody levels and greater B cell/plasmablast responses. A multi-antigen immunoassay to define the complex serological landscape and clinical associations is essential. METHODS: We developed a multiplex immunoassay and evaluated serum/plasma from adults with RT-PCR-confirmed SARS-CoV-2 infections during acute illness (N=52) and convalescence (N=69); and pre-pandemic (N=106) and post-pandemic (N=137) healthy adults. We measured IgA, IgG, and/or IgM against SARS-CoV-2 Nucleocapsid (N), Spike domain 1 (S1), receptor binding domain (S1-RBD) and S1-N-terminal domain (S1-NTD). RESULTS: To diagnose infection, the combined [IgA+IgG+IgM] or IgG for N, S1, and S1-RBD yielded AUC values -0.90 by ROC curves. From days 6-30 post-symptom onset, the levels of antigen-specific IgG, IgA or [IgA+IgG+IgM] were higher in patients with severe/critical compared to mild/moderate infections. Consistent with excessive concentrations of antibodies, a strong prozone effect was observed in sera from severe/critical patients. Notably, mild/moderate patients displayed a slower rise and lower peak in anti-N and anti-S1 IgG levels compared to severe/critical patients, but anti-RBD IgG and neutralization responses reached similar levels at 2-4 months. CONCLUSION: This SARS-CoV-2 multiplex immunoassay measures the magnitude, complexity and kinetics of the antibody response against multiple viral antigens. The IgG and combined-isotype SARS-CoV-2 multiplex assay is highly diagnostic of acute and convalescent disease and may prognosticate severity early in illness. ONE SENTENCE SUMMARY: In contrast to patients with moderate infections, those with severe COVID-19 develop prominent, early antibody responses to S1 and N proteins.

Inflammatory aneurysm of the thoracoabdominal aorta with associated dissection.

The inflammatory variant of aortic aneurysms has 3 unique features: marked thickening of the aneurysm wall, fibrosis of the adjacent retroperitoneum, and rigid adherence of the adjacent structures to the anterior aneurysm wall. Abdominal tenderness with or without a pulsatile abdominal mass is the most common finding, although it is present in only about 33% of patients. Systemic symptoms, such as fever, malaise, and weight loss, are reported in about 20% to 50% of patients. A contrast-enhanced computed tomography scan, magnetic resonance imaging, and a transesophageal echocardiogram are among the best modalities to evaluate for inflammatory thoracoabdominal aneurysm, but a transthoracic echocardiogram can frequently be very suggestive. Medical treatment options include corticosteroids or other anti-inflammatory and immunosuppressive therapies. Surgical intervention usually consists of a transperitoneal approach with infrarenal aortic clamping. This case review describes a 64-year-old woman with a history of hypertension and dyslipidemia who presented with anemia, lower back pain, and a recent 30-pound weight loss.

Empyema necessitans in the setting of pneumonia and parapneumonic effusion.

Empyema necessitans is a rare complication of pleural space infections and occurs when the infected fluid dissects spontaneously into the chest wall from the pleural space. This process may result from bronchopleural extension of a peripheral lung infection. These cases result from inadequate treatment of an empyema and usually occur after a necrotizing pneumonia or pulmonary abscess. We present two cases of empyema thoracic necessitans.

Group C streptococcal endocarditis.

Group C streptococcus is found in many domestic animals and rarely causes infection in human beings. Severe infections caused by these bacteria are associated with high morbidity and mortality rates. We present a case of group C streptococcus endocarditis with sequelae, right-eye endophthalmitis, and multilobar pneumonia caused by septic embolization from the infected mitral valve.