Background: The aim of this study was to analyze HCV RNA levels in serum, liver, and PBMC of patients with HIV and HCV co-infection with respect to patients with HCV mono-infection.

Methods: 42 patients (8 females, 34 males, age range 31-45, median 36 years) with HIV and HCV co-infection, and HIV infection controlled by HAART (median HIV RNA plasma level <50 copies/mL [range <50-12,817]; median CD4+  T-cell count 477/μL [range 166-1198]), and 91 patients (36 females and 55 males, age range 22-68, median 52 years) with HCV mono-infection were studied by parallel quantification of HCV RNA in serum, liver biopsy and PBMC and HCV genotyping. No patient had previously received interferon treatment.

Results: In the patient group with co-infection, HCV genotype was 1a/b in 24 patients (57%), 3a in 10 patients (23%), 4 in 7 patients (17%), and 2b in 1 patient (2%). Median liver HCV RNA was 16,666 genome equivalent (GEq)/μg total RNA (range: 469-131,578), 14,680,000 GEq/mL (252,000-118,900,000) in serum and 688 GEq/μg total RNA (0-8333)  in PBMC. In the group of patients with HCV monoinfection genotype was 1a in 7 patients (8%), 1b in 36 (39.5%), 2a/c in 35 (38.5), 4 in 2 (2%), and a mixture of 1b and 2a/c in 1 patient (1%). Median liver HCV RNA level was 113,636 GEq/μg total RNA (range 250-1,250,000), while serum, and PBMC levels were 6,640,000 GEq/mL (199,000-74,620,000) and 4733 GEq/μg total RNA (0-62,500), respectively.

Conclusions: Liver and PBMC HCV RNA levels were significantly (p<0.0001) lower in the group of patients with HIV-HCV co-infection compared to patients with mono-infection, while the HCV RNA serum values had an opposite trend, being significantly higher in co-infected patients in comparison to patients with mono-infection (p<0.005).