HTLV-2b among HIV type 1-coinfected injecting drug users in Spain

Human T cell lymphotropic virus type 2 (HTLV-2) infection is endemic in the American Indian population and Pygmy tribes in Africa. Nevertheless, HTLV-2 infection has been predominantly detected in U.S. and European injecting drug users (IDU). Noteworthy is that the HTLV-2a subtype is the main circulating variant in North America and Eastern Europe whereas the HTLV-2b subtype is mainly found in Western Europe, particularly in Italy and Spain where coinfection with HIV-1 is frequent. Twelve Spanish subjects infected with HTLV-2 were recruited for the study. All of them were IDUs coinfected with HIV-1. Molecular epidemiology was done by sequencing the LTR, env, and tax regions and by generating phylogenetic trees. The present study showed that all the sequences belonged to the HTLV-2b subtype and were closely related to other Spanish and Portuguese reported sequences, clearly differentiated from those belonging to the HTLV-2a subtype from Eastern Europe. Therefore, infection with HTLV-2b remains prevalent in Spain based on previous studies.

Observational study to evaluate clinical outcomes after first-line efavirenz-or lopinavir-ritonavir-based HAART in treatment-naive patients

PURPOSE

To evaluate clinical, immunological, and virological outcomes after first-line highly active antiretroviral therapy (HAART) with a regimen including either efavirenz (EFV) or lopinavir/ritonavir (LPV/r) in treatment-naive adult patients in routine clinical care.

METHOD

An ongoing prospective, observational follow-up study included all patients starting their first antiretroviral therapy (ART) with any of the studied regimens from July 1998 to July 2004. The follow-up period was finalized in September 2006, when all patients completed an observation of at least 96 weeks. Mortality rates, CD4 counts, viral suppression (HIV RNA below 50 copies/mL), and discontinuation of any component of the regimen were compared at 48 and 96 weeks.

RESULTS

Despite the worst immunological status of the LPV/r group patients at baseline, this regimen was at least as effective as the one based on EFV not only in terms of treatment durability but also in terms of virological responses, nevertheless with an apparently quicker immune recovery. In general terms, both regimens present similar tolerability and safety outcomes except for the higher risk of increasing triglyceride (TG) levels in the LPV/r group. Low durability was observed in both regimens.

CONCLUSION

In a routine clinical care setting, initial HAART containing LPV/r seems to present an effectiveness, tolerability, and toxicity similar to the one containing EFV.

Imported histoplasmosis: two distinct profiles in travelers and immigrants

BACKGROUND

Histoplasmosis is acquiring importance in nonendemic areas due to the increase in travel and immigration, being the most common systemic mycosis acquired by European travelers. Epidemiological studies show that the incidence of Histoplasma infection in these patients may be higher than previously believed and a wide clinical spectrum of disease may be observed.

METHODS

Cases of histoplasmosis diagnosed at a Tropical Medicine Referral Unit in Madrid, Spain, during the period January 1996 to December 2006 were reviewed.

RESULTS

Ten cases of histoplasmosis in travelers and immigrants are described. Five HIV-positive patients (four immigrants and one expatriate) all presented with progressive disseminated disease. Five HIV-negative patients (travelers) all presented with pulmonary disease: four with an acute pulmonary form (one with pleural involvement) and one patient was found to have residual pulmonary disease (lung nodule). Three of the travelers also had rheumatologic manifestations (arthromyalgias or arthritis).

CONCLUSIONS

Clinicians in nonendemic areas may be faced with patients with a diagnosis of histoplasmosis and although Histoplasma infection can have a varied and nonspecific clinical presentation, imported histoplasmosis may have two distinct profiles. Previously, healthy travelers may be exposed in endemic areas and mainly develop acute forms of the disease with a favorable outcome. Immigrants or expatriates from endemic areas who may be immunosuppressed due to HIV infection may experience reactivation of latent disease developing disseminated forms with high mortality rates. This infection should be considered in the differential diagnosis of diseases affecting travelers and immigrants.

Treatment options for AIDS patients with progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a demyelinating viral disease produced by the John Cunningham (JC) virus, which is ubiquitously distributed. Up to 80% of adults seroconvert to JC virus. Classically, PML is a life-threatening AIDS-defining disease of the CNS, usually occurring in severely immunocompromised individuals. Until now, and despite several therapeutic attempts, there is no specific treatment for PML. Soon after the widespread use of combination antiretroviral therapy (CART), several studies showed prolonged survival for patients with AIDS-associated PML who were treated with CART. The outcome of PML in patients receiving CART is unpredictable at disease onset. Prognostic markers are needed. The JC virus DNA detection in cerebrospinal fluid by nucleic acid amplification techniques and the CD4+ cell count are the most promising parameters. Higher levels of CD4+ cell counts were independently associated with an improved survival in different clinical observations. A summary of the main current knowledge about AIDS-related PML is presented. The most effective strategy is to optimize CART to completely suppress HIV-1 viral load and allow the best CD4+ T-cell immune recovery. Nowadays, AIDS-related PML is no longer an ultimately fatal disease. A substantial number of HIV-1-infected patients with this condition can improve with CART.

[Efficacy of atazanavir in treatment-naive patients]

The characteristics of atazanavir (convenient doses, good tolerance, and excellent lipid profile) makes it an attractive drug to be included in initial regimes. Clinical trials have been performed on patients with no previous antiretroviral treatment, either atazanavir without boost (400 mg once per day) or atazanavir boosted with ritonavir (400/100 mg). Although atazanavir without boost is effective, there is a tendency for a higher number of failures and a higher development of resistant mutations than in patients who fail with boosted atazanavir. Therefore, it is recommended to use boosted atazanavir in patients that start on treatment. In clinical studies, boosted atazanavir can be used with any nucleoside analogue. No pharmacokinetic or pharmacodynamic interaction problems have been detected with the two nucleoside combinations at fixed doses (tenofovir/FTC, abacavir/3TC). Randomised clinical studies have been carried out that compared atazanavir with other boosted protease inhibitors. In the comparative study with lopinavir/ritonavir administered two times a day, atazanavir/ritonavir once per day demonstrated noninferiority, with a similar efficacy regardless of the patient baseline viral load. The atazanavir/ritonavir virological efficacy did not appear to be affected by the baseline immunological status of the patients, which did influence the lopinavir/ritonavir response. Atazanavir/ritonavir is a useful drug combination in the initial treatment of HIV infected adult patients. Its increased virological and immunological efficacy, together with its ease of administration, good tolerance and excellent lipid profile makes it a PI of choice in these patients.

Patients' characteristics and clinical implications of suboptimal CD4 T-cell gains after 1 year of successful antiretroviral therapy

To describe characteristics and prognosis of patients with suboptimal immunological response to combined antiretroviral therapy (CART). Using data from a multicenter cohort study, we selected patients who initiated CART and showed suboptimal CD4-T cell response (defined as <50 cells/L increase) after 1 year of therapy, despite sustained virological suppression. Characteristics of those patients were compared with subjects who showed optimal immunological response. Of 650 patients with virological suppression, 108 (16.6%) showed suboptimal CD4-T cell response. Independent predictors of suboptimal response were previous injection drug use (OR, 1.85; 95% CI, 1.12-2.98) and age at CART initiation (OR, 1.04 per year increase; 95%CI, 1.01-1.06). Hepatitis C virus coinfection was not associated with impaired immunological response. As compared with patients with optimal immunological response, those with suboptimal response had a higher mortality rate (3.22 versus 0.71 per 100 person-years; p=.001), but a similar rate of new AIDS-defining events. In patients with sustained virological suppression with CART, previous injection drug use, but not hepatitis C virus coinfection, and older age at initiation of therapy were associated with suboptimal CD4 T-cell responses. Patients with suboptimal response had a higher mortality over time, mainly due to diseases other than AIDS-defining events.

Didanosine enteric-coated capsule: current role in patients with HIV-1 infection

Didanosine, which is a synthetic nucleoside analogue intracellularly phosphorylated to the active metabolite, inhibits the activity of HIV-1 reverse transcriptase by competing with the natural substrate. Currently, didanosine is mainly provided as an enteric-coated capsule. In vitro, the molecule is active against laboratory strains and clinical isolates of HIV-1 in resting and activated T cells and monocyte/macrophages. Didanosine may select for resistance mutations that may render the drug inactive against the virus; L74V and K65R remain as the main didanosine-related mutations. In vitro, phenotypic susceptibility to didanosine was decreased beyond a defined fold change clinical cut-off (1.7), and it is considered that genotypic resistance exists when five thymidine-associated mutations or four plus M184V are present. In vivo, clinical studies have shown that didanosine retains significant antiviral activity in patients who have up to five nucleoside analogue mutations at baseline. Didanosine is useful in patients with no previous therapy, as well as in experienced patients in whom one or more antiretroviral regimens has failed.Enteric-coated didanosine is taken once daily, its co-administration with food has been recently evaluated and a reduction of the efficacy of the antiretroviral treatment was not observed. Administered with lamivudine (or emtricitabine), it can be considered a good alternative for use in the nucleoside analogue backbone included in combination therapies for antiretroviral-naive patients. Didanosine could be used in initial treatments for patients intolerant of zidovudine, abacavir or tenofovir. It can be included in once-daily combination regimens, which are more convenient and patient friendly.Prospective, observational and open-label studies, as well as clinical trials (with durations between 24 and 96 weeks), have demonstrated the safety and efficacy of didanosine plus lamivudine (or emtricitabine) plus efavirenz (or nevirapine) in previously untreated HIV-1-infected patients. The administration of didanosine to treatment-experienced patients has been evaluated in two different contexts: patients in whom previous therapies have failed (rescue therapy) and those with controlled viraemia who are switched to a didanosine-containing regimen for simplification.Adverse events associated with the administration of didanosine have been well known since the initial clinical trials with the drug. Gastrointestinal intolerance, peripheral neuropathy and hyperamylasaemia/pancreatitis were the most frequently reported. In the highly active antiretroviral therapy (HAART) era, the rate of adverse events has decreased. The tolerability of didanosine has been clearly improved with the development of the enteric-coated capsule. Severe manifestations of mitochondrial toxicity, including lactic acidosis and abnormal fat distribution, are rare complications, and occur most frequently when didanosine is used in combination with stavudine.

Severity of the toxicity associated with combinations that include didanosine plus stavudine in HIV-infected experienced patients

BACKGROUND

The combination of didanosine (ddI) and stavudine (d4T) is no longer recommended as a first-line treatment because of toxicity, but it may be useful in experienced patients.

METHODS

Retrospective chart review of experienced patients on ddI plus d4T was conducted at a single institution, recording the development of adverse events as well as their severity and action taken. The risk of developing severe toxicities was estimated by Kaplan-Meier analysis.

RESULTS

A total of 616 patients were on ddI plus d4T for a median time of 12 months (interquartile range: 5.0-24.7 months). Among them, 213 (34.6%) had AIDS, 161 (27.4%) had CD4 counts <200 cells/mm, and 503 (81.2%) had >2 previous treatment failures. Adverse events related to ddI plus d4T were recorded in 136 patients (22.1%), which were mild to moderate in 118 (19.1%) patients and severe in 18 (2.9%) patients. The mean times to development of severe and nonsevere adverse events were 72 (95% confidence interval [CI]: 70 to 75) weeks and 52 (95% CI: 48 to 55) weeks, respectively. The probability of developing severe adverse events was related to the nadir CD4 count, with higher risk in patients with <200 cells/mm (log rank test, P = 0.045).

CONCLUSIONS

Multiexperienced patients treated with combinations, including ddI plus d4T, frequently develop drug-related toxicity, but these events are rarely severe. Thus, these drugs can still be considered a valid option for salvage regimens.

Antiretroviral therapy in AIDS patients with tuberculosis

Tuberculosis associated with HIV infection continues to be an important problem throughout the world. Since the advent of HAART, the medication of HIV-infected patients who have to receive concomitant treatment for tuberculosis has become a difficult task. The two main problems faced by clinicians include the significant pharmacokinetic interactions between rifamycins, a cornerstone in antituberculosis therapy, and protease inhibitors and nonnucleoside reverse transcriptase inhibitors, which are essential components of antiretroviral combination regimens, as well as the best moment to initiate antiretroviral therapy in patients with tuberculosis. The therapy of choice for patients with no previous antiretroviral experience includes an antituberculous regimen with rifampin and an efavirenz-based antiretroviral regimen. No dose adjustments of these drugs seem to be necessary. Nevirapine can be an alternative to efavirenz in this situation. For patients who cannot take efavirenz, either due to resistance or intolerance, rifabutin and a boosted protease inhibitor can be coadministered, with the necessary dose adjustments. No definite recommendations can be given regarding the optimal timing of antiretroviral therapy, but a delay of two months after initiation of antituberculosis therapy would be advisable and seems to be safe in most patients.

High virological failure rate in HIV patients after switching to a regimen with two nucleoside reverse transcriptase inhibitors plus tenofovir

BACKGROUND

Regimens with two nucleoside analogue reverse transcriptase inhibitors (NRTI) plus tenofovir DF have been associated with a high failure rate when administered as first line therapy. Little is known about patients with undetectable viral loads who are switched to these regimens.

METHODS

A post-hoc review of the virological outcomes at 24 weeks of patients who switched from a successful (< 50 copies/ml) highly active antiretroviral therapy regimen to a tenofovir plus two NRTI combination.

RESULTS

Fifty-five patients started a two NRTI plus tenofovir regimen mostly because of previous toxicity/intolerance of the original drugs (74%). After 24 weeks, only 17 patients (31%) remained virologically suppressed. Patients with a regimen including a didanosine plus tenofovir-based regimen had significantly poorer outcomes than those on other combinations (success rate 5 versus 47.1%, P = 0.001). In contrast, patients on a regimen including zidovudine plus tenofovir showed a trend towards a better outcome (75 versus 27%, P = 0.083). Multivariate analysis confirmed the combination of didanosine plus tenofovir as the only variable associated with a higher rate of failure (odds ratio 17.7; 95% confidence interval 2.1-147; P = 0.007). Patients with previous reverse transcriptase mutations presented virological failure in all cases. At failure a new pattern, including the K65R mutation with M184V or thymidine analogue mutations, was observed.

CONCLUSIONS

Even in patients with suppressed viraemia, a two NRTI plus tenofovir regimen is associated with a high virological failure rate, but significant variations are found depending on the nucleosides included.

Lipid disorders in antiretroviral-naive patients treated with lopinavir/ritonavir-based HAART: frequency, characterization and risk factors

OBJECTIVES

The aim of this study was to evaluate the frequency, characteristics and risk factors of lipid changes associated with lopinavir/ritonavir treatment in antiretroviral-naive patients.

METHODS

A prospective cohort of 107 antiretroviral-naive HIV-infected patients was followed for 12 months after starting lopinavir/ritonavir-based highly active antiretroviral therapy.

RESULTS

At 12 months, percentages of patients with hypercholesterolaemia and hypertriglyceridaemia were 17.4% and 40%, respectively. Mean increases in total cholesterol and triglycerides were 40.7 and 73.3 mg/dL. There was a significant increase in both low-density and high-density (HDL) cholesterol, and no increase in the total cholesterol/HDL ratio (from 4.16 at baseline to 4.49 after 12 months). Baseline cholesterol > 200 mg/dL and triglycerides > 150 mg/dL were independent risk factors for dyslipidaemia, while hepatitis C coinfection appeared to be protective.

CONCLUSIONS

Patients with elevated lipid values at baseline have the greatest risk of developing hypercholesterolaemia and hypertriglyceridaemia after starting lopinavir/ritonavir. Antiretroviral-naive patients coinfected with hepatitis C have a low risk of developing hyperlipidaemia after starting lopinavir/ritonavir.

Espondilodiscitis y sacroileítis por Streptococcus agalactiae en adultos: caso clínico y revisión de la literatura

INTRODUCTION

Streptococcus agalactiae is a well-known pathogen related with infection in newborns, and in women during pregnancy and the puerperium. In recent years it has been described as a causal agent in invasive disease in immunodepressed adults and those with other severe underlying pathologies.

METHODS

We describe a case of S. agalactiae spondylodiscitis and concomitant bilateral sacroiliitis in an adult with no known underlying diseases. A systematic review of the related literature was performed (MEDLINE and EMBASE, up to December 2003).

RESULTS

The literature search retrieved only 33 cases of spondylodiscitis (predominance in men, 55-70 years old) and 13 cases of sacroiliitis (higher frequency in women, 30-40 years old) due to S. agalactiae. Simultaneous involvement of both locations of the axial skeleton is unusual.

CONCLUSION

Spondylodiscitis and sacroiliitis due to S. agalactiae is uncommon. S. agalactiae is an emerging pathogen in adults outside of the gestational and perinatal period. This micro-organism produces spondylodiscitis in the adult population over 50 years old. In contrast, sacroiliac involvement is described mainly in women in the reproductive age.

Influence of liver fibrosis on highly active antiretroviral therapy-associated hepatotoxicity in patients with HIV and hepatitis C virus coinfection

BACKGROUND

Coinfection with hepatitis C virus (HCV) and human immunodeficiency virus (HIV) is a known risk factor for hepatotoxicity in patients receiving highly active antiretroviral therapy (HAART). The aim of this study was to evaluate the role of HCV-related liver fibrosis in HAART-associated hepatotoxicity.

METHODS

In a prospective study involving 107 patients who underwent liver biopsy, fibrosis was graded according 5 stages, from F0 (no fibrosis) to F4 (cirrhosis). Hepatotoxicity was defined as an increase in levels of aspartate aminotransferase and alanine aminotransferase to >5 times the upper limit of normal, or a >3.5-fold increase if baseline levels were abnormal. The incidence of hepatotoxicity was compared with liver fibrosis stage and with time and composition of HAART.

RESULTS

Overall, 27 patients (25%) had hepatotoxic events (5.1 events/100 person-years of therapy). The incidence was greater for patients with stage F3 or F4 fibrosis (38%) than for those with stage F1 or F2 fibrosis (15%; 7.6 vs. 3 events/100 person-years; relative risk, 2.75; 95% confidence interval, 1.08-6.97; P=.013). Duration of HCV infection, duration of HAART, diagnosis of acquired immunodeficiency syndrome, HCV load, HCV genotype, and nadir CD4(+) cell count did not affect the risk of hepatotoxicity. Of the 86 patients who received nonnucleoside reverse-transcriptase inhibitors (NNRTIs), 11 (13%) developed liver toxicity. In these patients, fibrosis stages F1 and F2 were associated with similar rates of toxicity (3 events/100 person-years for patients who received nevirapine, 3.3 events/100 person-years for those who received efavirenz, and 3.4 events/100 person-years for those who received non-NNRTIs). There was a greater incidence among patients with F3 or F4 fibrosis who received NNRTIs (11.7 events/100 person-years for patients who received nevirapine, and 8.6 events/100 person-years for those who received efavirenz), compared with those who received non-NNRTIs (4 events/100 person-years).

CONCLUSIONS

HAART-associated hepatotoxicity correlates with liver histological stage in patients coinfected with HIV and HCV. There was no difference in hepatotoxicity risk for different antiretroviral therapies in patients with mild-to-moderate fibrosis.

CD4 cell recovery during successful antiretroviral therapy in naive HIV-infected patients: the role of intravenous drug use

We evaluated the impact of HIV risk practice on immune reconstitution in a prospective cohort of 288 patients (176 former injecting drug users) who maintained complete virus suppression for more than 24 months. Significant differences in CD4 cell counts at 6 and 24 months were detected. Multivariate analysis showed that drug use was an independent predictor of poor immunological recovery. Injection drug abuse impairs short and long-term CD4 cell recovery in HIV-positive patients initiating successful highly active antiretroviral therapy.

The role of liver biopsy in the management of chronic hepatitis C in patients infected with the human immunodeficiency virus

We evaluated the role of liver biopsy in the management of chronic hepatitis C in HIV-infected persons. Patients included had abnormal alanine transaminase (ALT) levels, detectable HCV RNA, and an interpretable liver biopsy. Demographic, epidemiologic, clinical, laboratory, histological, and therapeutic data were recorded in all patients. We also registered the clinical diagnosis of cirrhosis (previous to biopsy) and whether the biopsy result deferred the decision of initiating therapy. During the 33-month duration of the study, 112 patients were included. The degree of fibrosis in liver biopsies was none or mild (F0 or F1) in 47 patients (42%) and was significant or severe in 65 (58%). Seventeen patients (15%) had histological cirrhosis. By logistic regression analysis, only portal hypertension (odds ratio [95% confidence interval], 5.3 [1.05-25.9], P = 0.04) was independently associated with significant fibrosis. Overall, cirrhosis was predicted before biopsy in 29 patients (26%) by the caregiving physician, but only 8 of these were confirmed histologically. The clinical prediction of cirrhosis before biopsy had a sensitivity of 47%, a specificity of 78%, a positive predictive value of 28%, and a negative predictive value of 89%. Histological findings changed the decision to initiate HCV therapy in 19 patients (17%) because of little or no fibrosis. Liver biopsy is a useful tool in the management of HCV-HIV-coinfected persons. In addition to allowing grading and staging of the disease far better than any other method or combination of methods, it is important for making management decisions for patients coinfected with HCV and HIV.

High rate of didanosine-related mitochondrial toxicity in HIV/HCV-coinfected patients receiving ribavirin

BACKGROUND

Nucleoside analogues may induce mitochondrial toxicity, particularly didanosine. Ribavirin increases didanosine exposure, which might be clinically relevant when coadministered in HIV/HCV-coinfected patients.

OBJECTIVE

To evaluate, among 89 patients receiving highly active antiretroviral therapy (HAART) and therapy for chronic hepatitis C, clinically relevant mitochondrial toxicity in those treated with concomitant ribavirin and didanosine (n=35, 39%).

METHODS

From January 2000 to July 2002 longitudinal analysis of the incidence and clinical course of didanosine-related hyperamylasaemia, pancreatitis, hyperlactataemia/lactic acidosis or neuropathy. Risk factors were evaluated using univariate and multivariate Cox's proportional hazards model.

RESULTS

Among 35 patients who received concomitant didanosine (400 mg/day in 86%) and ribavirin (> or = 10 mg/kg/day in 91%), 20 (57%) developed one or more adverse events after a mean of 87 days. Most frequent laboratory abnormalities were hyperamylasaemia (18 patients, 51%) and hyperlactataemia (eight patients, 23%). Acute pancreatitis and symptomatic hyperlactataemia developed in 10 (28%) and six (17%) patients, respectively. Two patients (6%) with pancreatitis and severe lactic acidosis died; the other patients recovered uneventfully despite continuation of anti-HCV therapy in 83% after didanosine withdrawal in 40%. In the Cox's model higher baseline amylase levels (HR: 1.04, 95% CI: 1.02-1.06, P=0.001) and three nucleoside reverse transcriptase inhibitor-based HAART (HR: 5.3, 95% CI: 1.73-16.24, P=0.003) were significantly associated to toxicity.

CONCLUSIONS

The coadministration of didanosine and ribavirin should be avoided in HIV/HCV-coinfected patients, due to a high rate of clinically significant toxicity, particularly in triple nucleoside-based HAART. Amylase levels should be strictly monitored, especially if elevated at baseline.

Pegylated interferon alpha2b plus ribavirin for the treatment of chronic hepatitis C in HIV-infected patients

BACKGROUND

Hepatitis C virus (HCV) and HIV coinfection constitutes an important epidemiological and clinical problem. We evaluated the safety and efficacy of Pegylated interferon alpha2b (Peg-IFN) and a fixed dose of ribavirin in the treatment of chronic hepatitis C in HIV coinfection.

METHODS

Open, prospective study in HCV-HIV coinfected patients with persistently elevated alanine aminotransferase (ALT) levels and a liver biopsy showing either portal or bridging fibrosis. Therapy included Peg-IFN (50 micro g weekly) with ribavirin 800 mg for 48 weeks. The primary end point was sustained virological response (SVR). Univariate and multivariate analyses were performed to determine factors associated with response.

RESULTS

By intent-to-treat analysis, 11 of 35 patients (31%) reached SVR. SVR was significantly better for genotypes 2/3 than for genotype 1 (54% versus 21%; P < 0.05). By multivariate logistic regression analysis, only a non-1 genotype was an independent factor for SVR [odds ratio (OR), 6; 95% confidence interval (CI), 1.1-31.7; P < 0.005]. A decrease of at least 1.5 log10 HCV RNA at week 12 of therapy was highly predictive of SVR (OR, 49.9; 95% CI, 4.9-508.2; P < 0.001). Most patients developed adverse events, although only six patients (17%) discontinued treatment due to toxicity.

CONCLUSIONS

The combination of low doses of Peg-IFN plus a fixed dose of ribavirin resulted in a rate of SVR similar to that obtained with higher doses of the drugs in HIV-infected patients and lower than those obtained in non-HIV patients. Response at week 12 may be useful to help guide therapy in HCV-HIV co-infected patients.

High Rate of Didanosine-Related Mitochondrial Toxicity in HIV/HCV-Coinfected Patients Receiving Ribavirin

Background

Nucleoside analogues may induce mitochondrial toxicity, particularly didanosine. Ribavirin increases didanosine exposure, which might be clinically relevant when coadministered in HIV/HCV-coinfected patients.

Objective

To evaluate, among 89 patients receiving highly active antiretroviral therapy (HAART) and therapy for chronic hepatitis C, clinically relevant mitochondrial toxicity in those treated with concomitant ribavirin and didanosine ( n=35, 39%).

Methods

From January 2000 to July 2002 longitudinal analysis of the incidence and clinical course of didanosine-related hyperamylasaemia, pancreatitis, hyperlactataemia/lactic acidosis or neuropathy. Risk factors were evaluated using univariate and multivariate Cox's proportional hazards model.

Results

Among 35 patients who received concomitant didanosine (400 mg/day in 86%) and ribavirin (≥10 mg/kg/day in 91%), 20 (57%) developed one or more adverse events after a mean of 87 days. Most frequent laboratory abnormalities were hyperamylasaemia (18 patients, 51%) and hyperlactataemia (eight patients, 23%). Acute pancreatitis and symptomatic hyperlactataemia developed in 10 (28%) and six (17%) patients, respectively. Two patients (6%) with pancreatitis and severe lactic acidosis died; the other patients recovered uneventfully despite continuation of anti-HCV therapy in 83% after didanosine withdrawal in 40%. In the Cox's model higher baseline amylase levels (HR: 1.04, 95% CI: 1.02–1.06, P=0.001) and three nucleoside reverse transcriptase inhibitor-based HAART (HR: 5.3, 95% CI: 1.73–16.24, P=0.003) were significantly associated to toxicity.

Conclusions

The coadministration of didanosine and ribavirin should be avoided in HIV/HCV-coinfected patients, due to a high rate of clinically significant toxicity, particularly in triple nucleoside-based HAART. Amylase levels should be strictly monitored, especially if elevated at baseline.