HIV-associated lipodystrophy is a condition characterized by loss of
subcutaneous fat
The subcutaneous tissue (), also called the hypodermis, hypoderm (), subcutis, superficial fascia, is the lowermost layer of the integumentary system in vertebrates. The types of cells found in the layer are fibroblasts, adipose cells, and mac ...
associated with infection with
HIV
The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immune ...
.
Presentation
HIV-associated lipodystrophy commonly presents with fat loss in face, buttocks, arms and legs.
There is also fat ''accumulation'' in various body parts. Patients often present with "buffalo hump"-like fat deposits in their upper backs. Breast size of patients (both male and female) tends to increase. In addition, patients develop abdominal obesity.
Cause
The exact mechanism of HIV-associated
lipodystrophy
Lipodystrophy syndromes are a group of genetic or acquired disorders in which the body is unable to produce and maintain healthy fat tissue. The medical condition is characterized by abnormal or degenerative conditions of the body's adipose tissue. ...
is not fully elucidated. There is evidence indicating both that it can be caused by
anti-retroviral medications and that it can be caused by HIV infection in the absence of anti-retroviral medication.
Evidence implicating anti-retroviral medications
On the one hand, lipodystrophy seems to be mainly due to HIV-1
protease inhibitors
Protease inhibitors (PIs) are medications that act by interfering with enzymes that cleave proteins. Some of the most well known are antiviral drugs widely used to treat HIV/AIDS and hepatitis C. These protease inhibitors prevent viral replicat ...
. Interference with
lipid metabolism
Lipid metabolism is the synthesis and degradation of lipids in cells, involving the breakdown or storage of fats for energy and the synthesis of structural and functional lipids, such as those involved in the construction of cell membranes. In anim ...
is postulated as
pathophysiology
Pathophysiology ( physiopathology) – a convergence of pathology with physiology – is the study of the disordered physiological processes that cause, result from, or are otherwise associated with a disease or injury. Pathology is the ...
. Also, the development of lipodystrophy is associated with specific
nucleoside reverse transcriptase inhibitor
Reverse-transcriptase inhibitors (RTIs) are a class of antiretroviral drugs used to treat HIV infection or AIDS, and in some cases hepatitis B. RTIs inhibit activity of reverse transcriptase, a viral DNA polymerase that is required for replicati ...
s (NRTI).
Mitochondrial toxicity
Mitochondrial toxicity is a condition in which the mitochondria of a body's cells become damaged or decline significantly in number; it occurs as a side effect of certain antiretroviral drugs used to treat human immunodeficiency virus, or HIV.
C ...
is postulated to be involved in the
pathogenesis
Pathogenesis is the process by which a disease or disorder develops. It can include factors which contribute not only to the onset of the disease or disorder, but also to its progression and maintenance. The word comes from Greek πάθος ''pat ...
associated with NRTI.
Evidence implicating HIV infection alone
On the other hand, there is evidence that
HIV-1
The subtypes of HIV include two major types, HIV type 1 (HIV-1) and HIV type 2 (HIV-2). HIV-1 is related to viruses found in chimpanzees and gorillas living in western Africa, while HIV-2 viruses are related to viruses found in the sooty mangabey ...
infection on its own contributes to the development of the lipodystrophic
phenotype
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological proper ...
by interfering with some key genes of
adipocyte
Adipocytes, also known as lipocytes and fat cells, are the cells that primarily compose adipose tissue, specialized in storing energy as fat. Adipocytes are derived from mesenchymal stem cells which give rise to adipocytes through adipogenesis. I ...
differentiation and
mitochondrial
A mitochondrion (; ) is an organelle found in the cells of most Eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is use ...
function on patients which have not received antiretroviral treatment.
Management
GHRH analogs such as
tesamorelin can be used to treat HIV-associated lipodystrophy.
Prognosis
Reversion of lipodystrophy does not occur after withdrawal of protease inhibitors.
[
]
See also
* Drug-induced lipodystrophy
Drug-induced lipodystrophy is a cutaneous condition that presents as one or multiple depressed areas (i.e. indentations), usually on the proximal extremities, ranging from under a few centimeters to greater than 20 cm in diameter.
See also
...
* Lipodystrophy
Lipodystrophy syndromes are a group of genetic or acquired disorders in which the body is unable to produce and maintain healthy fat tissue. The medical condition is characterized by abnormal or degenerative conditions of the body's adipose tissue. ...
* List of cutaneous conditions
Many skin conditions affect the human integumentary system—the organ system covering the entire surface of the body and composed of skin, hair, nails, and related muscle and glands. The major function of this system is as a barrier against t ...
References
External links
{{Authority control
Conditions of the subcutaneous fat
HIV/AIDS