title: Serum levels of immunoglobulin free light chains in patients with chronic hepatitis C presenting cryoglobulinemia.
abstract: Hepatitis C virus (HCV) infects B-lymphocytes, provokes cellular dysfunction and causes lymphoproliferative diseases such as cryoglobulinemia and non-Hodgkin's B-cell lymphoma. In the present study, we investigated the serum levels of kappa and lambda free light chains (FLC) of immunoglobulins and the kappa/lambda FLC ratio in Brazilian patients with chronic HCV infection and cryoglobulinemia. We also analyzed the immunochemical composition of the cryoglobulins in these patients. Twenty-eight cryoglobulinemic HCV patients composed the target group, while 37 HCV patients without cryoglobulinemia were included as controls. The median levels of kappa and lambda FLC were higher in patients with cryoglobulinemia compared to controls (p=0.001 and p=0.003, respectively), but the kappa/lambda FLC ratio was similar in patients with and without cryoglobulinemia (p>0.05). The median FLC ratio was higher in HCV patients presenting with advanced fibrosis of the liver compared to HCV patients without fibrosis (p=0.004). Kappa and lambda FLC levels were strongly correlated with the IgA, IgG and IgM levels in the patients with cryoglobulinemia. In patients without cryoglobulinemia, the kappa FLC level was only correlated with the IgG level, whereas the lambda FLC were weakly correlated with the IgA, IgG and IgM levels. An immunochemical pattern of mixed cryoglobulins (MC), predominantly IgM, IgG, IgA and kappa light chain, was verified in these immune complexes. We concluded that HCV-infected patients presenting cryoglobulinemia have vigorous polyclonal B-lymphocyte activation due to chronic HCV infection and persistent immune stimulation.
authors.affiliation: Programa de Pós-Graduação em Imunologia, Universidade Federal da Bahia, Salvador, BA, Brazil.
authors.forename: Isabela S
authors.initials: IS
authors.lastname: Oliveira
authors.affiliation: Programa de Pós-Graduação em Imunologia, Universidade Federal da Bahia, Salvador, BA, Brazil.
authors.forename: Milena S
authors.initials: MS
authors.lastname: Cabral
authors.affiliation: Programa de Pós-Graduação em Imunologia, Universidade Federal da Bahia, Salvador, BA, Brazil.
authors.forename: Larissa S
authors.initials: LS
authors.lastname: Jesus
authors.affiliation: Serviço de Gastroenterologia, Hospital Universitário Professor Edgard Santos, Universidade Federal da Bahia, Salvador, BA, Brazil.
authors.forename: Raymundo
authors.initials: R
authors.lastname: Paraná
authors.affiliation: Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal da Bahia, Salvador, BA, Brazil.
authors.forename: Ajax M
authors.initials: AM
authors.lastname: Atta
authors.affiliation: Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal da Bahia, Salvador, BA, Brazil. Electronic address: mluiza@ufba.br.
authors.forename: Maria Luiza B
authors.initials: ML
authors.lastname: Sousa Atta
mesh_terms: D016022:Case-Control Studies; D003449:Cryoglobulinemia / Q000209:etiology*; D003450:Cryoglobulins / Q000032:analysis*; D005260:Female; D019698:Hepatitis C, Chronic / Q000097:blood / Q000150:complications*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007145:Immunoglobulin kappa-Chains / Q000097:blood*; D007146:Immunoglobulin lambda-Chains / Q000097:blood*; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged
chemical_list: D003450:Cryoglobulins; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains
keywords: B-cell polyclonal activation; Chronic hepatitis C; Cryoglobulin; Free light chain