The role of immune suppression and HHV-8 in the increasing incidence of HIV-associated multicentric Castleman's disease.
BACKGROUND
In HIV cohorts with access to highly active antiretroviral therapy (HAART), the incidence of Kaposi's sarcoma (KS) is falling; however, the incidence of multicentric Castleman's disease (MCD) in HIV has not previously been described.


METHODS
The incidence of HIV-associated MCD was calculated from a prospective HIV database with 56 202 patient-years of follow-up and compared with KS. Univariate and multivariate analyses were carried out to identify factors associated with MCD. Plasma human herpesvirus (HHV)-8 DNA levels were measured in HIV-seropositive individuals with newly diagnosed MCD (n = 24), KS (n = 72), HIV-associated lymphoma (n = 74) and HIV-positive controls (n = 53).


RESULTS
From 24 cases of HIV-associated MCD, the incidence measured 4.3/10,000 patient-years [95% confidence interval (CI) 2.7-6.4]. The incidence in the pre-HAART (1983-1996), early-HAART (1997-2001) and later HAART (2002-2007) eras were 2.3 (95% CI 0.02-4.2), 2.8 (95% CI 0.9-6.5) and 8.3 (95% CI 4.6-12.6), respectively, representing a statistically significant increase over time (P < 0.05). In contrast, from 1180 cases of KS, the incidence in this cohort decreased with time. Multivariate analysis demonstrated that a nadir CD4 count >200/mm(3), increased age, no previous HAART exposure and non-Caucasian ethnicity were all associated with an increased risk of MCD. Plasma HHV-8 DNA levels were higher in patients with newly diagnosed MCD than with KS, lymphomas or HIV-positive controls (Mann-Whitney U-test, P < 0.0001).


CONCLUSIONS
The incidence of HIV-associated MCD is increasing. It appears to occur more frequently in older HIV-positive individuals with well-preserved immune function.
Powles
T
T
Department of Medical Oncology, Barts and the London Medical School, London, UK.
Stebbing
J
J
Bazeos
A
A
Hatzimichael
E
E
Mandalia
S
S
Nelson
M
M
Gazzard
B
B
Bower
M
M
D023241:Antiretroviral Therapy, Highly Active; D005871:Castleman Disease / Q000150:complications / Q000453:epidemiology* / Q000276:immunology / Q000821:virology; D015331:Cohort Studies; D015658:HIV Infections / Q000150:complications* / Q000188:drug therapy / Q000276:immunology; D019288:Herpesvirus 8, Human / Q000302:isolation & purification*; D006801:Humans; D015994:Incidence; D011446:Prospective Studies