No abstract

IFN induction in combination with ribavirin does not increase the sustained virological response rate among patients infected with HCV. Absence of steatosis is an independent predictor of sustained virological response in patients infected with genotypes 1a/1b.

All Candida albicans isolates in Norwegian microbiological laboratories in 1991 judged clinically important (except vaginal isolates) were collected. The isolates were tested for susceptibility to fluconazole with an agar dilution test and a commercially available agar diffusion test. A total of 212 strains (95%) were susceptible to fluconazole, and MICs for most of the strains (92%) were .1.56 pg/ml. The agar diffusion test using a 15-,Lg tablet and a 48-h incubation period separated resistant from susceptible strains with a wide margin. The only exception was a strain for which the MIC was 6.25 ILg/ml. The difference in zone size between the resistant and the susceptible populations of strains was 11 mm. Accordingly, it appears that the agar diffusion test is an appropriate method for detecting fluconazole resistance. The 12 fluconazole-resistant isolates originated from eight AIDS patients with oral or esophageal Candida infections. Seven of the patients had been given fluconazole for 1 month or more, often as self medication. Four had infections that were clinically resistant to fluconazole; one additional patient responded only when the dose was increased. All isolates recovered from these patients were analyzed by multilocus enzyme electrophoresis. The 12 C. albicans isolates belonged to five electrophoretic types, but three of four patients attending one hospital had isolates belonging to one electrophoretic type. One possible explanation for this finding could be that a nosocomial spread of resistant strains has occurred.

Patients with chronic hepatitis C respond differently when treated with interferon. We randomized 116 patients with chronic hepatitis C in order to compare two dosage regimens of recombinant interferon alpha 2a:3 MIU x 3 per week for 6 months (arm A) or 6 MIU x 3 per week for 3 months and then 3 MIU x 3 per week for 3 months (arm B). There were no significant differences concerning outcome between the two dose regimens: sustained clearance of HCV viremia 6 months after the end of treatment was obtained in 12/59 (20%) in group A compared with 18/57 (32%) in group B (p = 0.24). In patients with genotype 1a, 4/31 (13%), in genotype 1b, none of 9 (0%), 9/15 (60%) in genotype 2, and 17/58 (29%) in genotype 3, showed sustained clearance of HCV viremia 6 months after the end of treatment (p = 0.002). In a stepwise logistic regression analysis, only pretreatment viral load (p = 0.0001), genotype (p = 0.001) and age (p = 0.04) were identified as independent predictors of sustained clearance of HCV viremia. Liver histology as assessed by Knodell index was significantly improved in patients with sustained HCV RNA response 6 months after the end of treatment (5.2 +/- 2.2 vs 2.6 +/- 2.2, p < 0.001), but not in responders with relapse or in non-responders. In conclusion, stepwise logistic regression analysis showed that viral load, HCV genotype and age were the only independent predictors for sustained HCV RNA response.

The human immunodeficiency virus type 1 (HIV-1) load is an important marker of disease progression and treatment efficacy in patients with HIV-1 infection. In recent years, an increase in the number of samples with detectable HIV-1 RNA has been reported among patients with previously suppressed viral loads, affecting clinical patient care and leading to repeat measurements of viral load and drug resistance. This rise seems to have coincided with the increased use of plasma preparation tubes (PPTs) for sample collection, and we have aimed to explain why PPTs might yield elevated HIV-1 RNA levels. The impacts of different sample-processing procedures on HIV-1 RNA levels were compared retrospectively. Prospectively, the presence of different cells and cell-associated HIV-1 nucleic acids in paired plasma samples from PPTs centrifuged before (PPT1) and after (PPT2) transportation to the laboratory was compared. A retrospective analysis of 4,049 patient samples with <1,000 HIV-1 RNA copies/ml showed elevated HIV-1 RNA levels in plasma from PPT1 compared with the levels from PPT2 and standard EDTA-containing tubes. Prospective data revealed cell-associated HIV-1 nucleic acids and abundant blood cells in plasma from PPT1 but not from the corresponding PPT2. The levels of HIV-1 RNA correlated with the lymphocyte counts in plasma in PPT1. Cells could be removed by the recentrifugation of PPT1 before analysis. In conclusion, the transportation of PPTs after centrifugation may render cells in the plasma fraction containing cell-associated HIV-1 nucleic acids that contribute significantly to the HIV-1 RNA copy numbers in patients with low viral loads.