Purified Human IgG3 Isotype Control Antibody (Low Endotoxin, Azide-Free) Functional Grade

Background: Mortality in patients with community-acquired pneumonia (CAP) remains high despite improvements in treatment. Objective: To determine immunoglobulin levels in patients with CAP and impact on disease severity and mortality. Methodology: Observational study. Hospitalized patients with CAP were followed up for 30 days. Levels of immunoglobulin G (IgG) and subclasses, immunoglobulin A (IgA) and immunoglobulin M (IgM) were measured in serum within 24 hours of CAP diagnosis. Results: Three hundred sixty-two patients with CAP were enrolled - 172 ward-treated and 190 intensive care unit-treated. Intensive care unit-treated patients had significantly lower values of IgG1, IgG2, IgG3 subclasses, and IgA than ward-treated patients. Thirty-eight patients died before 30 days. Levels of IgG2 were significantly lower in non-survivors than survivors ( P= .004) and IgG2 <301 mg/dL was associated with poorer survival according to both the bivariate (hazard ratio 4.47; P < .001) and multivariate (HR 3.48; P = .003) analyses. Conclusions: Patients with CAP with IgG2 levels <301 mg/dL had a poorer prognosis and a higher risk of death. Our study suggests the usefulness of IgG2 to predict CAP evolution and to provide support measures or additional treatment. (C) 2016 Elsevier Inc. All rights reserved.

Aims To determine the role of serum and tissue IgG2 in orbital biopsies with the histological features of IgG4related disease (IgG4-RD) in comparison with non-IgG4related orbital inflammatory disorders (OID), including autoimmune disorders. Methods This is an international (Sheffield, UK, and Singapore) collaborative, retrospective case review of 69 patients (38 from Singapore National Eye Centre and 31 from Royal Hallamshire Hospital, Sheffield) with orbital inflammatory biopsies between 2002 and 2016. Clinical information and histology were reviewed and cases were classified into three groups: Group 1: IgG4-RD orbital inflammation (n=43); Group 2: idiopathic OID (n=12) and Group 3: autoimmune OID (n=14). Serum IgG1, IgG2, IgG3 and IgG4 levels were collated where available and immunohistochemistry (IHC) for tissue IgG2 plasma cells was performed. Results Dual IHC showed IgG2 plasma cells as a distinct population from IgG4 plasma cells. Significant (twofold) serum IgG2 elevation was noted among IgG4RD (group 1), idiopathic (group 2) and autoimmune OID (group 3). Similarly, significant elevation of tissue IgG2 plasma cells was also seen among IgG4-RD (group 1), idiopathic and autoimmune OID (groups 2 and 3). Conclusions Significant elevations of serum IgG2 and tissue IgG2 plasma cells are present in orbital IgG4RD in comparison with non-IgG4 orbital inflammation (idiopathic and autoimmune OID), suggesting that IgG2 may play a role in IgG4-RD. A serum IgG2 cut-off > 5.3 g/L was found to be 80% sensitive and 91.7% specific for orbital IgG4-RD, with an accuracy of 0.90. Tissue IgG2 and IgG4 subclass reporting may provide additional insight regarding the ' IgG4-RD' pathogenesis.