Parvovirus B19 infection, hepatitis C virus infection, and mixed cryoglobulinaemia.
BACKGROUND
Infection with human parvovirus B19 (B19) has been reported in a few patients with various vasculitis syndromes. Mixed cryoglobulinaemia (MC), a model of small vessel size vasculitis, may result from numerous infectious diseases, particularly hepatitis C virus (HCV) infection.


OBJECTIVE
To assess the prevalence of seric B19 infection markers in a large series of patients with MC, with or without HCV infection.


METHODS
Sixty-four patients were studied: essential MC (EMC, n = 19), MC associated with non-infectious diseases (non-essential MC, n = 9), and patients with HCV infection with (HCV-MC, n = 18) or without MC (HCV-no-MC, n = 18). Patients were considered to have MC if two successive determinations of their serum cryoglobulin concentration were above 0.05 g/l. Serum samples were analysed for specific IgG and IgM antibodies to B19 by enzyme immunoassay. B19 DNA detection was performed by polymerase chain reaction using a set of primers located in the VP1 gene, separately in serum and in cryoprecipitates to investigate a possible capture of B19 DNA in cryoprecipitate. The study also looked for a possible enrichment for of IgG antibodies to B19 in MC.


RESULTS
The presence of specific IgG antibodies to B19 was found in 68% EMC, 56% non-essential MC, 78% HCV-MC, and 78% HCV-no-MC. No patient of either group had specific IgM antibodies to B19, or B19 DNA in serum or in cryoprecipitate. Overall, IgG antibodies to B19 were found in 46 of 64 (72%) serum samples, a prevalence quite similar to the prevalence in general adult population (> 60%). A specific enrichment of IgG antibodies to B19 in the MC was not found.


CONCLUSIONS
These results suggest that B19 infection is neither an aetiological factor of EMC, nor a cofactor that may lead to MC production in patients with chronic HCV infection.
Cacoub
P
P
Department of Internal Medicine, Hôpital La Pitié-Salpétrière, Paris, France.
Boukli
N
N
Hausfater
P
P
Garbarg-Chenon
A
A
Ghillani
P
P
Thibault
V
V
Musset
L
L
Huraux
J M
JM
Piette
J C
JC
D000914:Antibodies, Viral / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D016009:Chi-Square Distribution; D003449:Cryoglobulinemia / Q000150:complications / Q000276:immunology / Q000821:virology*; D004279:DNA, Viral / Q000032:analysis; D006526:Hepatitis C / Q000150:complications / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008875:Middle Aged; D010322:Parvoviridae Infections / Q000150:complications / Q000276:immunology*; D016732:Parvovirus B19, Human / Q000235:genetics / Q000276:immunology*
D000914:Antibodies, Viral; D015415:Biomarkers; D004279:DNA, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M