Differential humoral immune response against hepatitis C virus antigenic synthetic peptides in infected patients with and without mixed cryoglobulinaemia.
In this study we have evaluated the prevalence of antibodies against core region peptides (residues 1-28, 21-38 and 51-68), the envelope 1, the non-structural (NS) 4 and 5 proteins of hepatitis C virus (HCV) in sera from 65 chronically HCV-infected patients, 47 with mixed cryoglobulinaemia (MC+) and 18 without (MC-). The major binding sites were located within the core region. Regions 1-28 and 51-68 were recognized by a similar proportion of MC+ and MC- patients, while peptide 21-38 was less frequently detected by samples from MC+ patients (65.5% versus 100%, P = 0.011). The patterns of the reactions showed a minimum of three binding sites: one, located within region 51-68, was shared by both groups; a second determinant was identified at residues 1-21 for MC+ patients and at residues 28-38 for MC- patients; a third, not exactly localized, lay between residues 1 and 38. Recognition of NS5 peptides was not significantly different between MC+ and MC- patients, but while the former mostly reacted either with peptide 1 (residues 2294-2309) (five of 15 sera) or with peptide 2 (residues 2304-2319) (nine of 15 sera), the latter group showed a more scattered reaction. Antibodies to HCV peptides prevalently belonged to IgGl subclass. However, whereas IgGl antibodies against peptide 21-38 and peptide 1 of NS5 were more frequently found in MC- rather than in MC+ patients (100% versus 63.8%, P = 0.003, and 22.2% versus 4.2%, P = 0.025, respectively), IgG3 antibodies against region 1-28 were more frequent in MC+ patients (53.19% versus 16.6%, P = 0.0078). Overall, the data suggest that a differential humoral immune response to HCV antigens occurs in patients with and without cryoglobulinaemia.
Gabrielli
A
A
Istituto di Clinica Medica Generale, Ematologia ed Immunologia Clinica, Università di Ancona, Italy.
Zhang
Z X
ZX
Cherubini
G
G
Candela
M
M
Savoldi
S
S
Manzin
A
A
Clementi
M
M
Amoroso
A
A
Sallberg
M
M
D000328:Adult; D000368:Aged; D001483:Base Sequence; D003449:Cryoglobulinemia / Q000276:immunology* / Q000821:virology*; D005260:Female; D005838:Genotype; D016174:Hepacivirus / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D006526:Hepatitis C / Q000276:immunology* / Q000821:virology; D018937:Hepatitis C Antibodies / Q000096:biosynthesis* / Q000145:classification; D018936:Hepatitis C Antigens / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000145:classification; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000276:immunology*; D014758:Viral Core Proteins / Q000276:immunology; D014759:Viral Envelope Proteins / Q000276:immunology; D017361:Viral Nonstructural Proteins / Q000276:immunology
C087035:E1 protein, Hepatitis C virus; D018937:Hepatitis C Antibodies; D018936:Hepatitis C Antigens; D007074:Immunoglobulin G; D010455:Peptides; D014758:Viral Core Proteins; D014759:Viral Envelope Proteins; D017361:Viral Nonstructural Proteins