Levels of serum IgG subclasses in patients with liver disease: A retrospective study

Abstract

Viral and alcoholic liver disease, drug induced liver disease (DILD), primary biliary cirrhosis (PBC) and autoimmune hepatitis (AIH) are among the most common liver diseases observed in clinical practice. These diseases lack unique clinical characteristics at the beginning of pathogenesis, which renders specific diagnosis difficult. Immunoglobulin G (IgG) subclasses are the main isoform of antibodies that can be found in the serum that serve important protective roles in immunity. The present study aimed to investigate the serum IgG subclass distribution in patients with the five common liver diseases aforementioned. The present study retrospectively recorded and analyzed the serum IgG subclass levels of different patients, who were grouped according to their clinical diagnosis. Serum IgG subclass levels were measured using immunonephelometric assays. IgG3 levels were found to be significantly increased whereas IgG4 levels were significantly decreased in patients with PBC. In patients with AIH, IgG1 levels were significantly increased. By contrast, IgG1/IgG level ratios in patients with viral liver disease were significantly increased. No clear pattern in the distribution characteristics of IgG subclasses could be observed in cohorts with alcoholic liver disease and DILD in the present study. Additionally, model for end-stage liver disease scores regarding IgG1 in patients with AIH shared a synergistic relationship. Anti-mitochondrial antibody subtype M2 (AMA-M2) and IgG3 in patients with PBC demonstrated a synergistic relationship. These results suggested that IgG subclasses may be used as biomarkers to further the understanding of liver disease, which could allow for early diagnosis.

The association of serum immunoglobulin and complement levels and liver fibrosis and inflammation stage in patients with chronic hepatitis B

“…Serum IgG4 was often used to exclude IgG4‐related diseases. Zheng W's study indicated that certain serum IgG subclass levels were selectively increased or decreased depending of the type of liver disease, and IgG1/IgG level ratios in patients with viral liver disease were significantly increased 26 . Thus, compared with IgG2, IgG3 and IgG4, more attention should be paid to IgG1 in CHB patients.…”

Solution structures of human myeloma IgG3 antibody reveal extended Fab and Fc regions relative to the other IgG subclasses

“…This may relate to a subclass switch from IgG3 to the other three IgG subclasses, in the course of which the disease becomes more chronic, and we speculate that this might be related to the long hinge of IgG3. Serum IgG3 was also found to be significantly increased in primary biliary cirrhosis, this liver disease being another autoimmune disorder (38)(39)(40).…”

The Role of Immunoglobulin G4 in Outcomes of Primary Sclerosing Cholangitis

“…In other autoimmune diseases, such as systemic lupus erythematosus, differential expression/elevation of IgG subclasses have been reported with significantly higher levels of IgG1, IgG2, and IgG3 compared to healthy controls, but no correlation has been shown between IgG subclasses and distinct clinical features [ 7 ]. IgGs are the main isoform of antibodies that can be found in the serum and that serve important protective roles in immunity [ 8 ]. The present study aimed to investigate serum IgG subclass distribution in patients with PSC and its possible association with PSC outcomes.…”