[Physiopathology and treatment of acquired immunodeficiency syndrome].

The last pandemia of the century, that of the Acquired Immunodeficiency Syndrome (AIDS) caused by the Human Immunodeficiency Virus (HIV), continues to advance with gigantic steps at about 18,000 new infections per day worldwide. In the last four years, breakthroughs have been achieved and new medications have been introduced, which have impacted the progression of HIV and its disease, decreasing associated morbidity and mortality. During the course of infection, HIV replicates actively producing as much as 10(10) genetically different virions (quasi-species), which relates to immune escape, higher pathogenicity and drug resistance. Persistent viral replication causes T CD4+ cell destruction and immunodeficiency through several mechanisms. Currently, there are 14 approved anti-retrovirals that when used as triple regimens have been able to decrease opportunistic infections, hospitalization and mortality rates. Unfortunately, these regimens still have many limitations, do not cure and can only suppress the virus effectively in 50% of the treated patients. Besides, when they are inadequately used there is associated resistance development. On the other hand, indications for treatment initiation are changing continuously and heading towards a conservative approach. In the case of salvage regimens, there are only general guidelines that have not been evaluated in clinical studies. Resistance assays have great limitations and their use is very specific. All these factors have made antiretroviral treatment a very complicated issue that should be prescribed and followed by an expert.