DID YOU KNOW...
... that incidence of Pulmonary Arterial Hypertension (PAH) is increased in people infected with the Human Immunodeficiency Virus (HIV)?
Since its discovery in the early 1980s, HIV has become a pandemic. In 2008 alone, more than 33.4 million people were living with HIV, whilst over 25 million people died from it1 . Today, the number of infected people is still growing. Because Highly Active Anti-Retroviral Therapy (HAART) is lengthening life expectancy of HIV-positive individuals, there is increased incidence of secondary complications associated with infection, such as Secondary Pulmonary Arterial Hypertension1 .
PAH occurs when the lumenal diameter of the pulmonary artery—the blood vessel that carries blood from the right ventricle of the heart to the lungs—decreases due to cell proliferation and migration (Fig 1). This increases the pressure within the pulmonary artery. Normal pulmonary artery pressure is ~15 mmHg, while a hypertensive pulmonary artery pressure is > 25 mmHg at rest. This increased pulmonary artery pressure forces the heart to work harder. As in the case of a bodybuilder “pumping iron”, when the heart works harder, the muscle grows larger. However, this growing heart tissue reduces the amount of blood that can be pumped from the right ventricle and can lead to heart failure. The pathology associated with HIV-related PAH is similar to that found in other forms of PAH, and the cause is unknown2. These pathologies lead to shortness of breath, fatigue, and life-threatening complications3. The prospect of one life-threatening illness that destroys immune function is daunting to most, yet for many people, this is a reality worsened further by another fatal disease, which destroys the ability of your heart to pump blood.
Since the first report of HIV-associated PAH in 19884 , evidence suggests that there is greater than a million-fold rise in incidence of PAH amongst the HIV-positive population5,6. Surprisingly, most of the research in this field has only taken place in the past decade, likely due to the increased incidence within this group. One of the challenges in treatment of secondary PAH in HIV patients is the necessity to treat the PAH without having a negative impact on the retroviral treatment7 . In order to overcome this challenge in a still growing HIV-positive population, we need far more research in this field. Until then, people with HIV will still be at greater risk for developing PAH.
2. Talwar A, Sarkar P, and Rosen MJ. 2009. Pulmonary arterial hypertension in human immunodeficiency virus infection. Postgrad Med. 121(5): 56-67.
3. Cicalini S, Chinello P, Grilli E, and Petrosillo, N. 2009. Treatment and outcome of pulmonary arterial hypertension in HIV-infected patients: a review of the literature. Curr HIV Res. 7(6): 589-596.
4. Goldsmith GH Jr., Baily RG, Brettler DB, Davidson WR Jr, Ballard JO, Driscol TE, Greenberg JM, Kasper CK, Levine PH, and Ratnoff OD. 1988. Primary pulmonary hypertension in patients with classic hemophilia. Ann Intern Med. 108(6): 797-799.
5. Rich S (ed). 1998. World Health Organization: Primary Pulmonary Hypertension --Executive Summary, World Symposium, Primary Pulmonary Hypertension. http:// www.who.int/ncd/cvd/pph.html
6. Limsukon A, Saeed A, Ramasamy V, Nalamati J, and Dhuper S. 2006. HIV-related pulmonary hypertension. Mt Sinai J Med. 73(7): 1037-1044.
7. Degano B, Sitbon O, and Simonneau G. 2009. Pulmonary arterial hypertension and HIV infection. Semin Respir Crit Care Med. 30(4):440-447.