Tratamiento antirretroviral y toxicidad mitocondrial

Drug development for rare mitochondrial disorders

Currently, all treatment of mitochondrial disorders is performed with dietary supplements or by off-label use of drugs approved for other indications. The present challenge is translation of our collective knowledge of the molecular details underlying the pathophysiology of mitochondrial disorders into safe and effective therapies that are approved by the regulatory authorities. Molecular details permit precise diagnoses, but homogeneity is gained at the expense of limiting numbers of subjects for clinical trials and of small markets from which to recoup the considerable expense of drug discovery and development. The Food and Drug Administration recognizes that trial designs suitable for common diseases are often not feasible for rare disorders. They have developed a number of programs to facilitate development of novel therapies for such rare diseases, without compromise of regulatory standards. With advances in technology, including the use of biomarkers, replacement therapies and sophisticated trial designs, both biotechnology firms and, increasingly, large integrated pharmaceutical companies, are taking advantage of the opportunities in rare disorders. Precise molecular delineation of pathophysiology and of responsive patients has led to success rates with rare diseases that are significantly greater than those for common disorders. It appears likely, but not yet proven, that this may now be the case for rare mitochondrial disorders as well.

[In-utero antiretroviral exposure and mitochondrial toxicity in a cohort of uninfected infants born to HIV-1-infected women]

INTRODUCTION

In this study, we attempt to find out the percentage of uninfected infants born to HIV-infected women and exposed in-utero and perinatally to Antiretroviral Treatment (ART) that show high lactate levels, or any other mitochondrial damage markers (such as hypertransaminasaemia or hyperamylasaemia), during the first three months of age. We shall also establish whether certain drugs used in-utero are associated with higher lactate, transaminase or amylase levels.

METHODS

We analysed the available data from 623 uninfected infants born in the Spanish FIPSE cohort that were born in the period 2000-2005. The normal values for lactate, transaminases and amylase were set according to AIDS Clinical Groups Trials toxicity tables for infants.

RESULTS

The percentages of children with high lactate levels at 0.5; 1.5 and 3 months of age were 48%, 51.4% and 43% among those infants with available data. Respectively, the percentages of children with high AST values were 13.2; 10.4 and 17.2%. The values for high ALT were 3.3%; 3.4% and 5%. The percentages for hyperamylasaemia were 0%; 0.6% and 2.6%. We found no significant difference among the drugs used in utero for the four analysed biochemical markers along the first three months of age.

CONCLUSIONS

We have found a high proportion of hyperlactataemia among infants exposed in-utero to ART, as shown in other cohorts of similar characteristics. No morbidity or mortality was communicated to the cohort analysis group. No ART drug among those used in-utero was statistically associated with a higher proportion of high lactate levels in these infants.

[Lopinavir/ritonavir monotherapy. Possible indications]

Monotherapy with LPV/r maintains blocked viral replication when used as a simplification strategy from antiretroviral therapy with a boosted protease inhibitor and two nucleoside analogs in patients with an undetectable viral load for at least 6 months. This simplification strategy can be recommended to patients in these circumstances and who are able to maintain near perfect adherence. As recommended by the GESIDA guidelines, LPV/r monotherapy could be offered to patients with undetectable viral loads but who show symptoms or laboratory abnormalities attributable to nucleoside analog toxicity, or co-morbidities such as liver disease or nephropathy; LPV/r monotherapy could also be offered to patients who simply wish to take a lower number of pills. This strategy reduces treatment toxicity and costs, without jeopardizing the patient's future.

[Antiretroviral drug toxicity in human immunodeficiency virus infected children]

Paediatric Human Immunodeficiency Virus infection (HIV) nowadays is a chronic disease with an excellent long term prognosis, but lifelong combined antiretroviral treatment is required. However, an improved quality of life in this population is limited by adverse drug effects. The highest risk of treatment toxicity is developing a complete metabolic syndrome including: Hyperlipemia, lipodystrophy, insulin resistance, lactic acidosis, osteopenia, hypertension, and specific system and organ toxicity, such as the kidney, liver, CNS or bone marrow. The risk of cardiovascular disease adult life and also definitive bone mass damage are the most significant metabolic costs that have to paid for increased survival. Most of these toxicities were able to be adequately treated but, pharmacological interferences, patient intolerance and the high number of drugs are the problems that limit the adherence to treatment, which is essential for a good therapeutical efficacy. In this article, we present four HIV paediatric patients who presented with almost the whole range of metabolic toxicities, and a practical overview of therapeutical management.