Metabolic effects of switching to Biktarvy (B/F/TAF) in patients with HIV-1 treated with antiretroviral regimens that do not include tenofovir disoproxil fumarate (TDF) or tenofovir alafenamide (TAF): The Metabic study.

BACKGROUND: Studies on switching to tenofovir alafenamide (TAF)-based regimens raise concerns about a worse metabolic profile in people with HIV, even though most received tenofovir disoproxil fumarate (TDF) in their previous regimen. This study aims to evaluate changes in lipid fractions, glucose, and serum markers for hepatic steatosis (HS) after switching from a TDF- or TAF-sparing regimen to bictegravir/emtricitabine/TAF (B/F/TAF). METHODS: We performed a retrospective cohort study of people with HIV who switched to B/F/TAF from TDF- or TAF-sparing regimens between January 2019 and May 2022 with at least 6 months of follow-up. The primary endpoint was the absolute change in lipid fractions at 6 months. Secondary outcomes were changes in lipid fractions at 12 months and changes in other metabolic parameters (glucose, creatinine, and HS based on the triglyceride-to-glucose [TyG] ratio at 6 and 12 months). Changes were analysed using mixed linear regression models with random intercept and time as a fixed effect. RESULTS: The study included 259 people with HIV (median age 55 [interquartile range (IQR) 47-60] years; 80% male; 88% Caucasian; CD4+ T-cell count 675 [IQR 450-880] cells/mm3; 84.3% HIV-RNA <50 copies/mL). In total, 63 patients (30%) had hypertension, 93 (44%) dyslipidaemia, 30 (14%) diabetes, and 45% obesity/overweight. Most (60%) switched from integrase inhibitor-based regimens, and 21% switched from a boosted regimen. At 6 months, significant reductions were observed in total cholesterol (-7.64 mg/dL [95% confidence interval (CI) -13.52 to -1.76; p = 0.002]), triglycerides (-23.4 [95% CI -42.07 to -4.65]; p = 0.003), and TyG ratio (-0.14 [95% CI -0.23 to -0.05]; p < 0.001). CONCLUSION: In our real-life cohort, the effect of switching TDF-/TAF-sparing regimens to triple therapy with B/F/TAF improved total cholesterol, triglycerides, and serum markers of HS at 6 months and was neutral for the remaining metabolic parameters at 12 months.

Three-year efficacy of switching to dolutegravir plus lamivudine: A real-world study.

BACKGROUND: Dolutegravir (DTG) plus lamivudine (3TC) has proven highly efficacious as a switching strategy in virologically suppressed people with HIV (PWH). As this strategy was introduced relatively recently, real-world, long-term durability studies are lacking. METHODS: We performed a retrospective review of treatment-experienced patients who started DTG + 3TC in a cohort of PWH. HIV-RNA <50 copies/mL was analysed at 144 weeks in an intention-to-treat (ITT) analysis (missing = failure) and a per-protocol (PP) analysis (patients with missing data or changes for reasons other than virological failure were excluded). RESULTS: The study population comprised 358 PWH (19% women). Median age and time with HIV infection were 51.7 and 13.4 years, respectively. The median number of previous antiretroviral combinations was three. Previous virological failure was reported in 27.1% of patients, and the M184V resistance mutation was detected in 17 patients. At 144 weeks, the percentage of individuals with HIV-RNA <50 copies/mL was 77.4% (277/358) in the ITT analysis and 95.5% (277/290) in the PP analysis. A total of 68 participants were excluded from the PP analysis (data missing, 25, discontinuation due to toxicity, 19; other, 16; death, 8). Two people with virological failure selected resistance-associated mutations (M184V and M184V + R263K). HIV-RNA remained undetectable in 17 patients with a previous history of the M184V mutation. CONCLUSION: Our results confirm the real-world, long-term efficacy, tolerability and high genetic barrier of DTG + 3TC in treatment-experienced PWH. Although scarce, mutations causing resistance to nucleosides and integrase can emerge.

Efficacy and safety of dolutegravir/rilpivirine in real-world clinical practice. GeSIDA study 1119.

INTRODUCTION: Dolutegravir/rilpivirine (DTG/RPV) is an effective antiretroviral (ART) regimen endorsed by clinical trials as a switch therapy. The aim of our study was to analyse the efficacy and safety of DTG/RPV in real-world clinical practice. METHODS: Observational, multicentre study of patients who started DTG/RPV. Efficacy, adverse events and metabolic changes at 48 weeks were analysed. RESULTS: A total of 348 patients were included; median time of HIV infection was 21.1 years, 33.7% were AIDS cases; median nadir CD4 was 160 cells/µL; 90.5% had received ≥3 lines of ART and 179 (53.8%) had prior virological failure. Convenience (43.5%), toxicity/intolerance (28.4%) and interactions (17.0%) were the main reasons for starting DTG/RPV. Previous regimens were protease inhibitors (PI) (31.6%), non-nucleoside reverse transcriptase inhibitors (NNRTI) (20.4%) and integrase strand transfer inhibitors (INSTI) (14.9%). Efficacy (HIV-RNA <50 copies/mL) at 48 weeks was 89.7% (95% CI 86.1-92.6) by intention-to-treat (ITT) and 94.2% (95% CI 91.3-96.4) by on treatment (OT); 10 patients (3.1%) were not suppressed (3 had abandoned ART). There was a mean decrease in triglycerides, total cholesterol, low-density lipoprotein-cholesterol, glutamic-pyruvic transaminase (GPT), gamma-glutamyl transferase (GGT) and alkaline phosphatase; creatinine increased with a decrease in glomerular filtration rate. CONCLUSIONS: This study confirms the effectiveness, tolerability and safety of DTG/RPV in real-world clinical practice in a different population from clinical trials, with many years of infection, low CD4 nadir, several previous treatment lines, more than half with virological failures, and one-third diagnosed with AIDS. The switch to DTG/RPV was safe with few discontinuations due to adverse effects. Modifications of the lipid and liver profiles were favourable. There were no relevant changes in kidney function.

Genetic variants associated with steatohepatitis and liver fibrosis in HIV-infected patients with NAFLD.

Background and aims: Nonalcoholic fatty liver disease (NAFLD) is a common cause of liver damage in people living with HIV (PLWHIV). Several studies have investigated candidate genes for susceptibility to NAFLD and to steatohepatitis. PNPLA3, TM6SF2, and MBOAT7-TMC4 have been reported to be associated with elevated ALT levels and the histologic parameters of nonalcoholic steatohepatitis and severity of fibrosis. Our objective was to analyze the relationship between PNPLA3, TM6SF2, and MBOAT7-TMC4 and steatosis, steatohepatitis, and liver fibrosis in PLWHIV with NAFLD. Method: A cohort of PLWHIV with persistently elevated aminotransferase levels and suspected NAFLD who underwent liver biopsy and determination of genetic variants was assessed at two large centers in Spain. All participants included in the current study were genotyped for rs738409 (PNPLA3), rs58542926 (TM6SF2), and rs641738 (MBOAT7-TMC4). Results: The study population comprised PLWHIV who were on stable antiretroviral therapy [7.7% women; median age, 49.3 years (44-53.4)]. The median CD4 count was 829 (650-980), 60% had metabolic syndrome, and 18.5% were diabetic. The median BMI was 28.9 (25.5-30.8). Patients with liver steatosis (any grade) vs. nonsteatosis tended to harbor the PNPLA3 G allele variant [57.6% vs. 16.7% (p = 0.09)], but not TM6SF2 or MBOAT7-TMC4 variants. However, those with steatohepatitis vs. nonsteatohepatitis significantly more frequently had the PNPLA3 G allele variant [69.4% vs. 39.1% (p < 0.05)] and the MBOAT7-TMC4 A allele variant [75% vs. 42% (p < 0.05)]. In our cohort, the TM6SF2 gene variant was not associated with steatosis or steatohepatitis. The PNPLA3 G allele variant was associated with steatohepatitis [OR 4.9 (1.3-18); p 0.02] and liver fibrosis [OR 4.3 (1.1-17.4); p 0.04], and the MBOAT7-TMC4 A allele variant was associated with steatohepatitis [OR 6.6 (1.6-27.6); p 0.01]. Conclusion: The PNPLA3 G allele variant and MBOAT7-TMC4 A allele variant were associated with steatohepatitis and liver fibrosis in PLWHIV with persistently elevated aminotransferases and NAFLD. We recommend routine genotyping for PNPLA3 and MBOAT7-TMC4 in PLWHIV with NAFLD to identify those at higher risk of progression.

Assessment of Noninvasive Markers of Steatosis and Liver Fibrosis in Human Immunodeficiency Virus-Monoinfected Patients on Stable Antiretroviral Regimens.

Background: Nonalcoholic fatty liver disease (NAFLD) is a major nonacquired immune deficiency syndrome-defining condition for persons with human immunodeficiency virus (PWH). We aimed to validate noninvasive tests for the diagnosis of NAFLD in PWH. Methods: This is a cross-sectional study of PWH on stable antiretroviral therapy with persistently elevated transaminases and no known liver disease. The area under the receiver operating characteristic curve (AUROC) was calculated to compare the diagnostic accuracy of liver biopsy with abdominal ultrasound, transient elastography (TE) (including controlled attenuation parameter [CAP]), and noninvasive markers of steatosis (triglyceride and glucose index [TyG], hepatic steatosis index [HSI], fatty liver index [FLI]) and fibrosis ([FIB]-4, aminotransferase-to-platelet ratio index [APRI], NAFLD fibrosis score). We developed a diagnostic algorithm with serial combinations of markers. Results: Of 146 patients with increased transaminase levels, 69 underwent liver biopsy (90% steatosis, 61% steatohepatitis, and 4% F ≥3). The AUROC for steatosis was as follows: ultrasound, 0.90 (0.75-1); CAP, 0.94 (0.88-1); FLI, 0.81 (0.58-1); HSI, 0.74 (0.62-0.87); and TyG, 0.75 (0.49-1). For liver fibrosis ≥F3, the AUROC for TE, APRI, FIB-4, and NAFLD fibrosis score was 0.92 (0.82-1), 0.96 (0.90-1), 0.97 (0.93-1), and 0.85 (0.68-1). Optimal diagnostic performance for liver steatosis was for 2 noninvasive combined models of tests with TyG and FLI/HSI as the first tests and ultrasound or CAP as the second tests: AUROC = 0.99 (0.97-1, P < .001) and 0.92 (0.77-1, P < .001). Conclusions: Ultrasound and CAP performed best in diagnosing liver steatosis, and FLI, TyG, and HSI performed well. We propose an easy-to-implement algorithm with TyG or FLI as the first test and ultrasound or CAP as the second test to accurately diagnose or exclude NAFLD.

An alternative methodology to determine 210Pb activity soil profiles.

Unsupported 210Pb (Pbexc) is generated in air and is subsequently deposited on soil surface. The Pbexc can be used for sediment dating, soil erosion/sedimentation and air mass studies. In many cases, 210Pb activity determination (gamma ray 46.5 keV) cannot be performed due to the lack of efficiency calibration curve, especially when radioactive patron source is not available. This work presents an alternative methodology to obtain the 210Pb activity values, based on the activity definition and the attenuation coefficient determinations and assuming that soil samples coming from depth higher than 25 cm only contain 210Pb generated in the soil (Pbexc free, i.e., for those soil layers the 210Pb activity is equal to the 226Ra activity, at secular equilibrium). The proposed methodology was evaluated using soils from La Plata region, Argentina. The same soil samples were also analyzed in a second laboratory by the conventional methodology. The obtained results indicated that the proposed procedure can be used as a good alternative in cases where a calibration sample is not available.

Persistently altered liver test results in hepatitis C patients after sustained virological response with direct-acting antivirals.

Guidelines recommend evaluating persistent alteration of liver tests in HCV-infected patients after sustained virological response (SVR) and its influence on liver disease progression. We studied the prevalence, etiology, associated factors and evolutionary implications of persistent alteration of liver tests in HCV patients after direct-acting antivirals (DAA)-induced SVR. This was a prospective study of HCV-infected patients and SVR after DAA. Those with another previously diagnosed liver disease were excluded. Persistent alteration of liver tests was defined as any increase in ALT, AST or GGT at SVR12 and SVR24. Causes were determined according to standard clinical practice, including liver biopsy and follow-up transient elastography. A total of 1112 patients were included (70.8% males, median age 53 years, 38.8% cirrhosis, 34.9% interferon-experienced, 56.8% HIV-coinfected). Persistent alteration of liver tests was detected in 130/1112 patients (11.7% [95%CI: 9.7-13.6]). Its frequency differed between HCV-monoinfected (45/480: 9.4% [95%CI: 6.7-12.1]) and HIV-coinfected (85/632: 13.5% [95%CI: 10.7-16.2]) (P = .046). In multivariable analysis, cirrhosis (OR 2.12; 95%CI: 1.28-3.53; P = .004) and baseline transient elastography values (OR 1.03; 95%CI: 1.01-1.04; P = .000) were associated with persistent alteration of liver tests. The main etiologies were clinical diagnosis suggestive of nonalcoholic fatty liver disease in 47 (36.2%), alcohol in 30 (23.1%) and drug consumption in 19 (14.6%). Baseline and follow-up transient elastography was performed in 594 patients and showed a significantly different decrease in patients who did or did not have a persistent alteration of liver tests (-21.1% vs -30%, respectively; P = .003), independently of sex, HIV status or baseline TE value. In conclusion, persistent alteration of liver tests is not infrequent after SVR. It is associated with cirrhosis and baseline transient elastography, and the main cause is fatty liver. According to transient elastography changes, persistent alteration of liver tests seems to affect the course of liver disease.

Boceprevir plus pegylated interferon/ribavirin to re-treat hepatitis C virus genotype 1 in HIV-HCV co-infected patients: final results of the Spanish BOC HIV-HCV Study.

INTRODUCTION: Boceprevir (BOC) was one of the first oral inhibitors of hepatitis C virus (HCV) NS3 protease to be developed. This study assessed the safety and efficacy of BOC+pegylated interferon-α2a/ribavirin (PEG-IFN/RBV) in the retreatment of HIV-HCV co-infected patients with HCV genotype 1. METHODS: This was a phase III prospective trial. HIV-HCV (genotype 1) co-infected patients from 16 hospitals in Spain were included. These patients received 4 weeks of PEG-IFN/RBV (lead-in), followed by response-guided therapy with PEG-IFN/RBV plus BOC (a fixed 44 weeks was indicated in the case of cirrhosis). The primary endpoint was the sustained virological response (SVR) rate at 24 weeks post-treatment. Efficacy and safety were evaluated in all patients who received at least one dose of the study drug. RESULTS: From June 2013 to April 2014, 102 patients were enrolled, 98 of whom received at least one treatment dose. Seventy-three percent were male, 34% were cirrhotic, 23% had IL28b CC, 65% had genotype 1a, and 41% were previous null responders. The overall SVR rate was 67%. Previous null-responders and cirrhotic patients had lower SVR rates (57% and 51%, respectively). Seventy-six patients (78%) completed the therapy scheme; the most common reasons for discontinuation were lack of response at week 12 (12 patients) and adverse events (six patients). CONCLUSIONS: Response-guided therapy with BOC in combination with PEG-IFN/RBV led to an overall SVR rate of 67%, but an SVR rate of only 51% in patients with cirrhosis. The therapy was generally well tolerated. Although the current standards of care do not include BOC+PEG-IFN/RBV, the authors believe that this combination can be beneficial in situations where new HCV direct antiviral agent interferon-free therapies are not available yet.

Approximate total Fe content determined by Mössbauer spectrometry: Application to determine the correlation between gamma-ray-emitter activities and total content of Fe phases in soils of the Province of Buenos Aires, Argentina.

Pearson correlation coefficients between 40K, 226Ra and 232Th activities and the total Fe phase fractions yielded by Mössbauer spectroscopy have been calculated for soils of the Province of Buenos Aires, Argentina. Total fractions of Fe phases have been obtained from the relative fractions reported in previous works weighted by the Fe soil content and the recoilless-fraction of each Fe phase. An approximate method based on the relationship between the Mössbauer spectral absorption area (obtained from the 57Fe Mössbauer data) and the total Fe concentration (determined by colorimetric methods, after microwave assisted acid digestion of soil samples) has been used for the first time to determine the Fe concentration in soils with an accuracy of 15%. Protocol to extend the method for unknown samples is also discussed. The determined new coefficients differ from those reported previously. A significant and positive correlation between the total fraction of Fe2+ and the 40K activity values has been obtained. This result validates the hypothesis put forward in a previous work, i.e., that illite captures the 40K existing in the soil. In addition, with the new approximation, the Pearson correlation coefficients for the other natural radionuclides give values that indicate that the methodology reported here is appropriate to study the correlations between the activity values with the total fractions of Fe phases.

Inventories and concentration profiles of 137Cs in undisturbed soils in the northeast of Buenos Aires Province, Argentina.

Inventories and vertical distribution of (137)Cs were determined in La Plata region undisturbed soils, Argentina. A mean inventory value of 891 ± 220 Bq/m(2) was established, which is compatible with the values expected from atmospheric weapon tests fallout. The study was complemented with pH, organic carbon fraction, texture and mineralogical soil analyses. Putting together Southern Hemisphere (137)Cs inventory data, it is possible to correlate these data with the mean annual precipitations. The large differences in (137)Cs concentration profiles were attributed to soil properties, especially the clay content and the pH values. A convection-dispersion model with irreversible retention was used to fit the activity concentration profiles. The obtained effective diffusion coefficient and effective convection velocity parameters values were in the range from 0.2 cm(2)/y to 0.4 cm(2)/y and from 0.23 cm/y to 0.43 cm/y, respectively. These data are in agreement with values reported in literature. In general, with the growth of clay content in the soil, there was an increase in the transfer rate from free to bound state. Finally, the highest transfer rate from free to bound state was obtained for soil pH value equal to 8.

Assessment of natural radioactivity levels and their relationship with soil characteristics in undisturbed soils of the northeast of Buenos Aires province, Argentina.

Surface and depth profile concentrations (down to 50 cm) of ²³²Th chain, ²²6Ra, and 4°K radionuclides were determined in undisturbed coastal and inland soils of La Plata city region, Argentina, through their gamma-ray activity using a high-purity Ge detector spectrometer. These results were compared with superficial activities determined in soils from the surroundings of the Centro Atómico Ezeiza (Ezeiza Atomic Center) located in Ezeiza, Buenos Aires Province, Argentina. The hyperfine and magnetic Fe phase's properties of soil profiles were characterized by Mössbauer spectroscopy, magnetic hysteresis loops and AC magnetic susceptibility. No dependence of the activity of the ²³²Th natural chain on depth was found, whereas variations for ²²6Ra and 4°K activities were observed. Positive correlations, determined by the Pearson correlation coefficients, were established between 4°K, ²²6Ra and ²³²Th activity concentrations for the whole set of soil samples. The annual external equivalent dose for adults was similar for La Plata and Ezeiza regions, with average values of 0.08 ± 0.01 mSv and 0.06 ± 0.02 mSv, respectively. The thermal dependence of the AC magnetic susceptibility revealed the existence of magnetite and hematite. The Mössbauer spectra of all soils were made up of signals associated with α-Fe2O3, a paramagnetic relaxation component, and Fe³âº and Fe²âº doublets. In addition, the spectra of inland soils revealed the presence of Fe3O4. A negative correlation was found between the activity concentrations and the α-Fe2O3 and Fe3O4 relative fractions, whereas a positive correlation was found between the Fe³âº relative fraction and the 4°K activity.

[HIV-1 neuropathogenesis: therapeutic strategies against neuronal loss induced by gp120/Tat glycoprotein in the central nervous system]. / Neuropatogenesis inducida por el virus del sida: estrategias terapeuticas frente a la neurodegeneracion inducida por la glucoproteina gp120/Tat en el sistema nervioso central.

Neuroinflammation is a key process in the neuropathogenesis of AIDS virus since as a result of the aberrant activation of the chemokine receptors (CXCR4, CX3CR1 and CR5) produces proinflammatory cytokine release by infected cells, increases microglial neurotoxicity and generates lipoperoxides and reactive oxygen species (ROS) that eventually damage the neuron. Moreover, the neurotoxin Tat produces dendritic loss by interacting with the low-density lipoprotein receptor (LRP) and also overstimulates N-methyl D-aspartate receptors (NMDA). Furthermore, the aberrant interaction of glycoprotein gp120 with the CXCR4 chemokine receptor causes caspase-3-dependent apoptosis (ceramide is also released) activating apoptotic proteins (p53 and retinoblastoma), which are part of the neurotoxic mechanisms associated to neuronal dysfunction in neuroAIDS. Similarly, gliosis/microglial activation and the release of neurotoxic factors by infected monocytes with elevated amounts of certain chemokines in the cerebrospinal fluid (MCP-1 and fractalkine, among others) contribute to the neuropathogenesis of HIV-1. Alpha-synuclein and beta amyloid deposits have also been detected in post mortem brains of seropositives patients. In addition, there are studies have detected several systemic markers related with the degenerative effects of the virus and its neurotoxins on the central nervous system; such as osteopontin, CD163 and fractalkine, among others. Lastly, clinical trials have been conducted using protective strategies related that attempt to inhibit apoptotic proteins (GSK-3 beta), microglial activation inhibitors (minocycline), antioxidants (selegiline) or trophic factors (IGF-1, growth hormone or erythropoietin). These trials have shown that their treatments are beneficial and complementary to treat complications of HIV/AIDS.

Reliable low-cost capillary electrophoresis device for drug quality control and counterfeit medicines.

The proportion of counterfeit medicines is dramatically increasing these last few years. According to numerous official sources, in some pharmaceutical wholesalers in African countries, the proportion has reached 80%. Unfortunately, this situation is far to be improved due to lack of suitable analytical equipment allowing rapid actions of the Regulatory Agencies based on scientific consideration, at affordable cost and all over the drug supply chain. For that purpose, a network group considered that mater by building a low-cost original capillary electrophoresis (CE) equipment equipped with a new deep UV detector based on LED technology. The generic conditions for analysis were investigated: capillary zone electrophoresis (CZE) performed at acidic pH for basic drug molecules (i.e., quinine, highly used as the last antimalarial rampart), basic pH for compounds such as furosemide (a common diuretic drug) and at neutral pH for a well known antibiotic combination, trimethoprim/sulfamethoxazol. To evaluate the ability of the CE equipment for quantification, a full validation and a method comparison study were carried out for the CZE method dedicated to quinine determination. The validation involved the use of accuracy profile and total error concept to monitor the adequacy of the results obtained by the new prototype. The method comparison was based on the Bland and Altman approach by comparing results obtained by the low-cost CE and a conventional set-up. Subsequent validation studies were realized with neutral and acidic drug molecules, each focusing on a single concentration level calibration curve in order to maintain as low as possible the expenses due to reagents and thus the cost of analysis, as important advantages of CE for drug quality control.

Pegylated interferon {alpha}2a plus ribavirin versus pegylated interferon {alpha}2b plus ribavirin for the treatment of chronic hepatitis C in HIV-infected patients.

OBJECTIVES: The two currently available types of pegylated interferon (peg-IFN) used to treat hepatitis C have different pharmacokinetic properties. It is unclear how these differences affect response to therapy. We compared the effectiveness and safety of peg-IFN-alpha2a and peg-IFN-alpha2b, both with ribavirin, against chronic hepatitis C virus (HCV) infection in HIV-infected patients. METHODS: From the GESIDA HIV/HCV cohort, we analysed patients treated with peg-IFN-alpha2a (n = 315) or peg-IFN-alpha2b (n = 242). The primary endpoint was a sustained virological response (SVR). RESULTS: Both groups were well matched in baseline characteristics except for a higher frequency of injection drug users in the peg-IFN-alpha2b group than in the peg-IFN-alpha2a group (85% versus 76%; P = 0.01) and a higher frequency of bridging fibrosis and cirrhosis (F3-F4) in the peg-IFN-alpha2b group than in the peg-IFN-alpha2a group (42% versus 33%; P = 0.04). End-of-treatment response was significantly lower among patients treated with peg-IFN-alpha2b [40% versus 52%; odds ratio (OR), 1.63; 95% confidence interval (95% CI), 1.16-2.29; P < 0.01]. However, no significant differences were found in SVR between patients treated with peg-IFN-alpha2b and those treated with peg-IFN-alpha2a (31% versus 33%; OR, 1.09; 95% CI, 0.75-1.59; P = 0.655). Therapy was interrupted due to adverse events in 33 (14%) patients treated with peg-IFN-alpha2b and 47 (15%) patients treated with peg-IFN-alpha2a. CONCLUSIONS: No differences in effectiveness and safety were found between peg-IFN-alpha2b and peg-IFN-alpha2a for the treatment of chronic HCV infection in HIV-infected patients.

Tinnitus suppression in patients with cochlear implants.

OBJECTIVE: To determine the degree of tinnitus suppression provided by currently available multichannel cochlear implants and to determine factors that can influence this process. STUDY DESIGN: Prospective cohort. SETTING: Tertiary-care referral center. PATIENTS: Thirty-eight adult patients (18 years of age or older) with severe-to-profound hearing loss and tinnitus who met criteria for cochlear implantation. INTERVENTION: Cochlear implantation with a multichannel cochlear implant device. MAIN OUTCOME MEASURES: Patients rated the intensity of their tinnitus using a semiquantitative scale before and after cochlear implantation. These data were analyzed to determine the significance of the reduction of tinnitus after implantation. Tinnitus levels after implantation were also analyzed to determine whether the level of speech recognition, patient gender, or the implant type influenced the degree of tinnitus reduction. RESULTS: Statistical analysis revealed a significant reduction in tinnitus intensity in patients using cochlear implants, with 35 of 38 patients (92%) experiencing a reduction in tinnitus intensity. All multichannel implants studied afforded similar degrees of tinnitus suppression. The degree of tinnitus reduction was not correlated with speech recognition, as measured by CID Everyday Sentence scores. Female patients had significantly greater degrees of tinnitus before implantation, but both male and female patients demonstrated similar levels of tinnitus after implantation. No patient experienced greater levels of tinnitus after implantation. CONCLUSION: All currently available multichannel cochlear implant devices provide effective and similar levels of tinnitus suppression when activated. Exacerbation of tinnitus as a result of cochlear implantation does not represent a significant risk. The mechanisms by which cochlear implants exert tinnitus suppression are, as yet, unclear.