IgG4 Subclass in Malignant Melanoma

Abstract

Three hundred and ninety-seven sera from 185 melanoma patients were studied. These sera were classified into three groups according to stage of disease. An alteration in the level of the IgG4 subclass was found. It was related to the dissemination of disease. The percentage of abnormalities (either increased or decreased levels of IgG4) was more frequent in patients with stage II and III diseases (55 and 53%, respectively) than in patients with stage I(19%). The higher frequencies of high titers of IgG4 were essentially detected in advanced disease. The biologic significance of the increase of IgG4 in melanoma remains obscure. The increase may be related to the development of facilitating antibodies of the IgG4 subclass.

IgG4 subclass antibodies impair antitumor immunity in melanoma

“…Infiltrating IgG4 + cells in lesions of patients with extrahepatic cholangiocarcinomas and pancreatic cancers were recently reported (19,20), and early studies have indicated abnormalities in serum titers of IgG4 in patients with melanoma (21). Both the presence and potential biological role of IgG4 subclass antibodies in melanoma tumor lesions remain largely unknown.…”

A high number of IgG4-positive cells in gastric cancer tissue is associated with tumor progression and poor prognosis

“…However, the relationship between IgG4 and malignancy remains largely unexplored, although IgG4+ cells were reported to infiltrate extrahepatic cholangiocarcinomas and pancreatic cancers [25]. Abnormal serum titers of IgG4 have been observed in patients with melanoma [26], and IgG4 was recently reported to significantly impair the potency of tumoricidal IgG1 in a human melanoma xenograft mouse model [17]. Serum IgG4 was shown to correlate inversely with survival in patients with melanoma [17].…”

IgG4 antibodies and cancer-associated inflammation

“…Three decades ago, Daveau and colleagues reported altered levels of IgG4 antibodies in the serum of melanoma patients 7 . Although this indicated that B cells in melanoma patients undergo antibody class/subclass switching, the underlying mechanisms and significance remained unexplored.…”