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The diagnostic research process can be divided into five phases, designed to establish the clinical utility of a new diagnostic test—the index test. The aim of the present review is to illustrate the study designs that are appropriate for each diagnostic phase, using clinical examples regarding liver fibrosis diagnosed with transient elastography, when possible. Phase 0 is the preclinical pilot phase during which the validity, reliability, and reproducibility of the index test are assessed in healthy and diseased people. Phase I is designed to describe the distribution of the index test results in healthy people and its normal values. Phase IIA comprises studies designed to estimate the accuracy (sensitivity and specificity) of the index test in discriminating between diseased and nondiseased people in a clinically relevant population. Phase IIB studies allow the comparison of the accuracy of different index tests; Phase IIC studies aim to evaluate the possible harms of incorporating the index test in a diagnostic-therapeutic strategy. In phase III, diagnostic test-therapeutic randomized clinical trials aim to assess the benefits and harms of the new diagnostic-therapeutic strategy versus the present strategy. Phase IV comprises large surveillance cohort studies that aim to assess the effectiveness of the new diagnostic-therapeutic strategy in clinical practice. Conclusion: As common in clinical research, giving excessive weight to the results of single studies and trials is likely to divert from the totality of evidence obtained through the systematic reviews of these studies, conducted with rigorous methodology and statistical methods. (Hepatology 2014;60:408-418)

Liver disease may alter the pharmacokinetics of antiretrovirals and produce changes in plasma protein binding. The aim was to evaluate the pharmacokinetics of total and unbound lopinavir (LPV) in HIV-infected patients with and without hepatitis C virus (HCV) coinfection. Fifty-six HIV+ patients receiving lopinavir/ritonavir (LPV/r) (group I = 24 controls; II = 23 HIV/HCV-coinfected; III = 9 cirrhotic HIV/HCV-coinfected) were included. Total (n = 56) and unbound (n = 36) LPV pharmacokinetic parameters were determined at steady-state using validated high-performance liquid chromatography with ultraviolet detection and high-performance liquid chromatography-tandem mass spectrometry methods, respectively. Pharmacokinetic parameters (plasma concentration just before drug administration, peak concentrations in plasma, times to maximum plasma concentration, areas under the plasma concentration-time curve from 0 to 12 hours, and CL/F/kg) of both total and unbound LPV were calculated by standard noncompartmental methods and differences among groups evaluated (Kruskal-Wallis test).LPV apparent oral clearance normalized to body weight (median, interquartile range) was 55 (40-68), 59 (44-69), and 71 (53-78) mL/h/kg for groups I, II, and III, respectively (II vs. I, P = 0.52; III vs. I, P = 0.16). The areas under the plasma concentration-time curve from 0 to 12 hours were 110.4 (80.9-135.2), 103.4 (85.5-131.3), and 92.8 (87.4-116.3) microg h/mL for groups I, II, and III, respectively (II vs. I, P = 0.68; III vs. I, P = 0.71). Chronic liver impairment produced a slight, although not significant, decrease in plasma protein binding. The free-fraction of LPV increased ( approximately 21%) from 0.97% (0.80-1.06) in HIV+/HCV- patients to 1.18% (0.89-1.65) in HIV/HCV+ cirrhotic patients. The apparent oral clearance of unbound LPV (CLu/F/kg) in cirrhotic patients did not change significantly, supporting the concept that the clearance of unbound LPV in liver disease is not affected after being inhibited by low-dose ritonavir co-administration.LPV total and unbound pharmacokinetics were not affected by hepatic impairment, suggesting that no adjustment of LPV/r dose is required for HIV/HCV-coinfected patients with and without cirrhosis and moderate impairment of liver function.

In patients with chronic liver disease, the accuracy of ultrasound scan (US), spiral computed tomography (CT), magnetic resonance imaging (MRI), and alpha-fetoprotein (AFP) in diagnosing hepatocellular carcinoma (HCC) has never been systematically assessed, and present systematic review was aimed at this issue.Pertinent cross-sectional studies having as a reference standard pathological examinations of the explanted liver or resected segment(s), biopsies of focal lesion(s), and/or a period of follow-up, were identified using MEDLINE, EMBASE, Cochrane Library, and CancerLit. Pooled sensitivity, specificity, and likelihood ratios (LR) were calculated using the random effect model. Summary receiver operating characteristic (SROC) curve and predefined subgroup analyses were made when indicated.The pooled estimates of the 14 US studies were 60% (95% CI 44-76) for sensitivity, 97% (95% CI 95-98) for specificity, 18 (95% CI 8-37) for LR+, and 0.5 (95% CI 0.4-0.6) for LR-; for the 10 CT studies sensitivity was 68% (95% CI 55-80), specificity 93% (95% CI 89-96), LR+ 6 (95% CI 3-12),and LR- 0.4 (95% CI 0.3-0.6); for the nine MRI studies sensitivity was 81% (95% CI 70-91), specificity 85% (95%CI 77-93), LR+ 3.9 (95%CI 2-7), and LR- 0.3 (95% CI 0.2-0.5). The sensitivity and specificity of AFP varied widely, and this could not be entirely attributed to the threshold effect of the different cutoff levels used.US is highly specific but insufficiently sensitive to detect HCC in many cirrhotics or to support an effective surveillance program. The operative characteristics of CT are comparable, whereas MRI is more sensitive. High-quality prospective studies are needed to define the actual diagnostic role of AFP.

Objective: To evaluate the prevalence of HIV-related central nervous system (CNS) lesions (HIV-encephalitis and/or HIV-leukoencephalopathy: HIV-E/L) with and without concomitant opportunistic diseases in a large autopsy series, and to correlate it with the changes in antiretroviral treatment that have occurred since the beginning of the epidemic. Methods: We reviewed 1597 consecutive autopsies of HIV-positive patients performed between 1984 and 2000, and divided into four time periods on the basis of the therapeutic regimens available: 1984-1987, no therapy; 1988-1994, monotherapy (zidovudine); 1995-1996, dual combination therapy with nucleoside reverse transcriptase inhibitors (NRTI); and 1997-2000, triple combination therapy including two NRTI and at least one protease inhibitor or non-NRTI. The data concerning the treatment actually received were collected only for the patients who died during the last period. The X 2 -test was used to assess the significance of the differences in prevalence. Results: The CNS of 1210 patients (76%) was affected by opportunistic diseases, HIV-related lesions or both. The prevalence of HIV-related lesions in the four periods was respectively 54%, 32%, 18% and 15%; this reduction was statistically significant (P < 0.000001). During the last period, however, differences in HIV-E/L between treated and untreated patients were not statistically significant, although there were fewer than expected cases among the treated patients (six instead of eight) and more than expected among the untreated patients (10 instead of eight). Conclusions: These neuropathological data from a large autopsy series confirm clinical observations concerning the efficacy of antiretroviral treatment in reducing the frequency of HIV-related CNS lesions in AIDS patients.

The authors enrolled 1,029 patients with CD4 counts/= 200/microL and no CNS AIDS-defining events (CNS-AIDS) between January 1993 and December 1998. The primary end point was the first appearance of CNS-AIDS. Three different periods and different antiretroviral regimens were considered. During the median follow-up of 329 days, 144 patients (9.5%) developed CNS-AIDS. The independent predictors were CD4 counts and therapy. All regimens decreased the risk of CNS-AIDS. Highly active antiretroviral therapy led to a 95% risk reduction in comparison with untreated patients.

The authors enrolled 1,029 patients with CD4 counts