Reactivation of human herpesvirus 6 (HHV-6) infection in patients with connective tissue diseases.
BACKGROUND
Little is known about the involvement of human herpesviruses 6 and 7 (HHV-6 and HHV-7) in autoimmune connective tissue diseases (ACTD).


OBJECTIVE
To determine the prevalence of active infection with HHV-6 and HHV-7 in patients with ACTD.


METHODS
The presence and quantity of HHV-6 DNA was determined by quantitative real-time PCR in a cross-sectional study of serum, peripheral blood mononuclear cells, and tissues obtained from 58 ACTD patients and 38 healthy subjects (HS). Specific anti-HHV-6 antibody titer was also measured.


RESULTS
HHV-6 serum viremia occurred in a significantly higher proportion of ACTD patients compared to HS [26/58 (44.8%) vs. 1/38 (2.6%), p=0.001] with the highest reactivation frequency [7/10 (70%)] observed in patients with scleroderma. Moreover, HHV-6 in serum was associated with ACTD activity (22/38 vs. 4/20, p<0.05). Higher titers of HHV-6 antibodies were found in ACTD patients than in HS, although HHV-6 seroprevalence among patients with ACTD and HS was similar. HHV-7 viremia was not detected in any patients or HS controls.


CONCLUSIONS
The frequent reactivation of HHV-6 in scleroderma and other ACTD, especially when active, suggests that HHV-6 may play a role in the pathogenesis of these diseases.
Broccolo
Francesco
F
Department of Clinical Medicine, Prevention and Biotechnology, University of Milano-Bicocca, Via Cadore, 48, 20052 Monza, Italy. francesco.broccolo@unimib.it
Drago
Francesco
F
Paolino
Stefania
S
Cassina
Giulia
G
Gatto
Francesca
F
Fusetti
Lisa
L
Matteoli
Barbara
B
Zaccaria
Elisa
E
Parodi
Aurora
A
Lusso
Paolo
P
Ceccherini-Nelli
Luca
L
Malnati
Mauro S
MS
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood; D001327:Autoimmune Diseases / Q000821:virology*; D002648:Child; D003240:Connective Tissue Diseases / Q000150:complications* / Q000821:virology*; D003430:Cross-Sectional Studies; D004279:DNA, Viral / Q000235:genetics; D005260:Female; D015654:Herpesvirus 6, Human / Q000302:isolation & purification / Q000502:physiology*; D016199:Herpesvirus 7, Human / Q000302:isolation & purification / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods; D015995:Prevalence; D019349:Roseolovirus Infections / Q000150:complications* / Q000453:epidemiology* / Q000821:virology; D014766:Viremia; D014775:Virus Activation; D055815:Young Adult
D000914:Antibodies, Viral; D004279:DNA, Viral