Antibodies, Viral/immunology* ; COVID-19/immunology* ; Humans ; Immunoglobulin G/immunology* ; Immunoglobulin M/immunology* ; SARS-CoV-2/immunology*

Autoimmune Diseases ; immunology ; Gene Expression Regulation ; immunology ; Humans ; Immunoglobulin G ; genetics ; immunology ; Sclerosis ; genetics ; immunology ; pathology

Agglutinins ; immunology ; Anemia, Hemolytic, Autoimmune ; Humans ; Immunoglobulin G ; Infant, Newborn

AIMTo explore the role of humoral immunity in the pathophysiological process of freezing injury and the possible immune interference in the preventation and treatment of frostbite.

METHODSSevere experimental freezing injury model was made in Wistar rats( n = 20). The concentration of three types of immunoglobulin (IgG, IgA and IgM), two types of complement components (C3 and C4), and circulating immune complex (CIC) were measured respectively before and at 4h, 1d, 3d, and 5d after frostbite. At the same time, the tissue immune complex (TIC) in skeletal muscle and the contents of the red blood cell immune complex (RBC-IC) were also observed and then was the red blood cell immune adherence activity (RCIA).

RESULTSSerum IgG concentration decreased rapidly to the lowest level at 4 h after frostbite IgA concentration dropped to the nadir on 1 day after freezing. Decreases of both immunoglobulins were maintained during the 5 days after frostbite. The fate of both C3 and C4 were the same as those immunoglobulins. Freezing had rather less effect on IgM level. CIC concentration in serum, expressed as the percent of prefreezing increased rapidly and to the zenith on the 3 days post-freezing. By immunofluorescence microscopy, thin continuous linear pattern (IgG) was demonstrated along the SM on the first day post-freezing. Granular and nodular deposits (IgG) appeared along the SM as the time proceeded after frostbite. RBC-IC contents, expressed as the erythrocyte IC rosette rate, increased significantly and to the zenith on the 3 d post-freezing, while RCIA depressed to the nadir at the same time.

CONCLUSIONThe freezing frostbite is an immune complex related disease which have not been reported by others before.

Animals ; Antigen-Antibody Complex ; analysis ; immunology ; Frostbite ; blood ; immunology ; Immunoglobulin A ; immunology ; Immunoglobulin G ; immunology ; Immunoglobulin M ; immunology ; Immunoglobulins ; immunology ; Male ; Rats ; Rats, Wistar

OBJECTIVETo obtain recombinant human anti-EV71 antibodies from a EV71-associated hand-foot-and-mouth disease patient-derived antibody phage library.

METHODSA combinatorial human scFv library to enterovirus 71 (EV71) virus was constructed using antibody genes harvested from the blood of EV71 virus patients. The library was panned and selected by using purified VP1 protein of EV71 virus with phage display. After that the specific antibody was converted to full human IgG antibody with recombinant baculovirus/insect cell system.

RESULTSOne unique human scFv antibody specific for EV71 virus VP1 protein was obtained by ELISA, IFA and analysis of the antibody DNA sequence. The specific anti-VP1 human scFv antibody was converted to full human IgG antibody with recombinant baculovirus/insect cell system. The full human IgG antibody was tested in vitro for EV71 virus neutralization, resulting in no neutralizing activity with EV71 A type and EV71 C4 subtype.

CONCLUSIONThe obtained human anti-EV71 antibodies without neutralizing activity laid the foundation for diagnosis of human EV71-associated hand-foot-and-mouth disease.

Antibodies, Viral ; immunology ; Enterovirus ; immunology ; Enzyme-Linked Immunosorbent Assay ; Humans ; Immunoglobulin G ; immunology ; Peptide Library

Percutaneous renal biopsy was performed on a 34 year old male patient with mild proteinuria and microhematuria. Histopathologic examination showed a focal mesangiopathic glomerulonephritis, simulating a "minimal change" disease pattern by light microscope. Granular deposits of IgA, C3, IgG, IgM, and fibrinogen were present in the glomerular mesangial area by immunofluorescent technique. A special prevalence of IgA was found. The intensity of immunofluorescent staining was correlated with the mesangial proliferative reaction by light microscopy. Electron microscopy showed electron dense granular deposits in the mesangial areas. The glomerulonephritis in this patient was related with the IgA antibody associated mesangial immune complex deposit disease mediated by the classic complement pathway. This glomerulonephritis is known to have a good prognosis. The antigenic nature, the reason of predominant immune deposits in the mesangium, and the mechanism of a special prevalence of IgA and IgM immunoglobulin classes are discussed, and special attention to the value of immunofluorescent study of renal diseases, with a review of the literature, is given.
Adult ; Case Report ; Glomerulonephritis/immunology* ; Glomerulonephritis/pathology ; Human ; Immunoglobulin A/analysis* ; Immunoglobulin G/analysis* ; Kidney/ultrastructure ; Male

Acetaldehyde ; metabolism ; Alcoholics ; Alcoholism ; blood ; immunology ; Antibodies, Anti-Idiotypic ; Humans ; Immunoglobulin A ; immunology ; Immunoglobulin G ; immunology ; Immunoglobulin M ; immunology ; Protein Processing, Post-Translational

Immunoglobulin G4-related systemic disease (IgG4-RSD) is a recently defined emerging entity characterized by a diffuse or mass forming inflammatory reaction rich in IgG4-positive plasma cells associated with fibrosclerosis and obliterative phlebitis. IgG4-RSD usually affects middle aged and elderly patients, with a male predominance. It is associated with an elevated serum titer of IgG4, which acts as a marker for this recently characterized entity. The prototype is IgG4-related sclerosing pancreatitis or autoimmune pancreatitis (AIP). Other common sites of involvement are the hepatobiliary tract, salivary gland, orbit, and lymph node, however practically any organ can be involved, including upper aerodigestive tract, lung, aorta, mediastinum, retroperitoneum, soft tissue, skin, central nervous system, breast, kidney, and prostate. Fever or constitutional symptoms usually do not comprise part of the clinical picture. Laboratory findings detected include raised serum globulin, IgG and IgG4. An association with autoantibody detection (such as antinuclear antibodies and rheumatoid factor) is seen in some cases. Steroid therapy comprises the mainstay of treatment. Disease progression with involvement of multiple organ-sites may be encountered in a subset of cases and may follow a relapsing-remitting course. The principal histopathologic findings in several extranodal sites include lymphoplasmacytic infiltration, lymphoid follicle formation, sclerosis and obliterative phlebitis, along with atrophy and destruction of tissues. Immunohistochemical staining shows increased IgG4+ cells in the involved tissues (>50 per high-power field, with IgG4/IgG ratio >40%). IgG4-RSD may potentially be rarely associated with the development of lymphoma and carcinoma. However, the nature and pathogenesis of IgG4-RSD are yet to be fully elucidated and provide immense scope for further studies.
Autoimmune Diseases/*immunology ; Cholangitis, Sclerosing/*immunology ; Humans ; Immunoglobulin G/*immunology ; Lacrimal Apparatus/immunology ; Lymphatic Diseases/*immunology ; Pancreatitis, Chronic/*immunology ; Salivary Glands/immunology ; Sclerosis/immunology

Head ; pathology ; Humans ; Immunoglobulin G ; Neck ; pathology ; Nose Diseases ; immunology ; Pharyngeal Diseases ; immunology

OBJECTIVETo explore the immune response of silicotic rats to sheep red blood cells(SRBC).

METHODSSilicotic rats were immunized with SRBC by tracheal instillation(Group 1) or intraperitoneal injection (Group 2), and non-silicotic rats were immunized by tracheal instillation as normal control(Group 3). The levels of serum hemolytic index(HC50) were measured on 7, 12, 20, 25, and 32 days after primary immunization and 5, 12, 15 days after the second immunization. Special anti-SRBC IgG was measured with ELISA(A490 nm) on 12, 20, 25, 32 days and 5, 12, 15, 27 days respectively. Delayed-type hypersensitivity(DTH) to SRBC was measured 20 days after second immunization and DTH reaction was determined at 24, 48, 72, and 96 h after administration. Total cell count and cell populations in the bronchoalveolar lavage fluid(BALF), lung associated lymph node(LALN) and spleen weight, special IgG secreted from spleen cells were measured at the end of the experiment.

RESULTSThe HC50 of Group 1(47.4 +/- 1.0, 52.2 +/- 4.6, 31.1 +/- 11.9, 43.8 +/- 3.5, 33.6 +/- 16.8, 49.0 +/- 2.3, 92.9 +/- 20.2, 87.7 +/- 5.2) were statistically higher than those of Group 3(40.4 +/- 10.6, 2.8 +/- 2.5, 0.8 +/- 0.6, 6.6 +/- 5.8, 1.4 +/- 0.1, 36.5 +/- 16.5, 53.0 +/- 33.2, 2.6 +/- 2.2). The special anti-SRBC IgG response in Group 1(1.67 +/- 0.19, 1.98 +/- 0.36, 1.12 +/- 0.50, 1.38 +/- 0.30, 2.75 +/- 0.15, 2.60 +/- 0.28, 2.86 +/- 0.10, 2.50 +/- 0.20) were much stronger than those in Group 3 (0.59 +/- 0.30, 0.56 +/- 0.21, 0.21 +/- 0.16, 0.22 +/- 0.01, 0.81 +/- 0.25, 0.74 +/- 0.25, 0.69 +/- 0.26, 1.38 +/- 0.41). Furthermore, the results of DTH showed positive response and the ratios for diameter of skin rash > 5 mm at 24, 48, 72, 96 h were 16/16, 16/16, 16/16, 15/16 respectively in Group 1, while those in Group 3 were 8/15, 1/15, 1/15, 1/15 respectively. Total cell count in the BALF, LALN and spleen weight, and special IgG secreted from spleen cells in Group 1 were higher too. Group 2 expressed almost of the same but with mild immunologic responses as Group 1.

CONCLUSIONSilicosis-induced extremely strong DTH and over-response of humoral immunity to some antigens may contribute to the likelihood of silicosis complicated with tuberculosis.

Animals ; Erythrocytes ; immunology ; Hypersensitivity, Delayed ; etiology ; Immunization ; Immunoglobulin G ; blood ; Rats ; Sheep ; Silicosis ; immunology