Factors Affecting HIV Progression ~ Living with HIV in the Philippines

Factors Affecting HIV Progression

Posted by Pozziepinoy on 8:49 PM

I was researching on the factors affecting HIV progression and I came about this article from Wellness. com.

Age

Older patients: The older the HIV patient, the faster he/she is likely to progress to AIDS. The effect is most apparent in patients older than 40. Researchers estimate that the risk of developing AIDS increases 27-55% every ten years.

According to a meta-analysis of 38 studies that involved more than 13,000 HIV patients, age and time since diagnosis were significant factors in determining the rate of HIV progression. Patients who developed HIV antibodies between the ages of 15 and 24 lived an average of 12.5 additional years. These patients progressed to AIDS after an average of 11 years. Patients who developed HIV antibodies between the ages of 45 and 54 lived an average of 7.9 additional years. These patients progressed to AIDS after an average of 7.7 years.

While the exact reason for this is unknown, some researchers suggest that older patients have a decreased ability to replace the CD4 T-cells that HIV infects and destroys. It is also unclear whether this is a result of the thymus gland's inability to produce new CD4 T-cells. Others suggest that older patients may have lower levels of chemokines, white blood cells that help fight off HIV.

Younger patients: HIV progression is also faster among patients who are younger than 13 years old, especially newborn babies who are born with the virus. This is likely because the newborn's immune system is not yet fully developed. Newborn babies do not begin to make their own antibodies (proteins that detect and bind to foreign substances like viruses) until they are about six months old.

Co‑Infections

Cytomegalovirus (CMV): Many types of herpes viruses, including cytomegalovirus (CMV), may increase the risk of developing AIDS. Herpes viruses produce proteins that may increase the speed at which HIV replicates. Several studies have suggested that patients who have both HIV and CMV are likely to develop AIDS quicker than those who only have HIV.

However, recent research has produced conflicting results, and the role of CMV as a possible co-factor remains unknown. For instance, one study found that CMV only affected disease progression in individuals who were already diagnosed with AIDS.

Based on the theory that CMV and other herpes viruses may increase HIV replication, researchers have evaluated the effect of anti-herpes treatment in HIV patients. Based on the results of several studies, it has been suggested that high doses of the anti-herpes drug acyclovir (Zovirax®) may increase survival time in HIV patients, particularly in those who have advanced HIV. However, other studies have found no effect of acyclovir treatment on survival time in HIV patients. Further research is warranted in order to make a firm conclusion.

Hepatitis C virus (HCV): Hepatitis C virus (HCV) appears to cause a rapid progression of both HIV and HCV-related diseases. Despite modern-day antiretroviral therapy (ART), patients infected with both HIV and HCV still have a greater risk of death than those only infected with HIV.

According to recent research, HCV's impact on HIV progression varies, depending on the genetic makeup of HCV. Also, patients who are infected with several different genetic types of HCV are likely to experience even faster HIV progression. Some researchers suggest that ART may decrease the impact HCV has on HIV progression.

Herpes virus type 6: Herpes virus type 6 (HHV-6) has also been suggested as a possible factor in HIV progression. The virus infects CD4 T-cells and produces a protein that may make increase the rate at which HIV replicates inside the white blood cells. However, one study evaluated long-term non-progressed HIV patients who had herpes viruses and based on their results, the researchers suggested that HHV-6, HHV-7, and HHV-8 are not co-factors in HIV progression.

T -lymphocyte virus: According to some studies, co-infection with the retrovirus human T-lymphocyte virus type 1 (HTLV-1) may increase the risk of an HIV-infected patient developing AIDS.

Ethnicity And Location

It has been suggested that Africans living in the United Kingdom develop AIDS and die more quickly than non-Africans. However, recent research does not support this claim. According to a review of more than 1,050 HIV-infected Africans and 992 HIV-infected non-Africans diagnosed with the disease between 1982 and 1995, there was not a significant difference in survival rates between the two groups. The Africans lived an average of 82 months, while the non-Africans lived an average of 78 months. The researchers also reported no significant difference in the CD4 cell counts or rates of progression.

The researchers suggested that it was highly likely that the African patients studied were infected with a different strain of HIV (called HIV-2) than the one that normally infects homosexual men and injection-drug users in Europe and North America (called HIV-1). If HIV-2 does not cause HIV progression quicker outside of Africa, this suggests that environmental factors, such as lack of access to antiretroviral therapy (ART) and treatment for opportunistic infections, lead to the faster progression rates in Africa.

Other research suggests that HIV progression rates among individuals living in Uganda are similar to those in developed countries. The researchers estimated that the average time from HIV exposure to an AIDS diagnosis was 9.4 years.

However, some studies suggest that a common genetic mutation among Africans may increase the patient's risk of developing HIV, and increase the rate of disease progression.

Another study conducted in the United States found no difference in viral load levels (number of HIV viral particles in the blood) among different racial groups, after controlling for access to medical care, socio-economic status, and CD4 cell counts.

Gender

Based on several studies in both adults and children, it appears that gender does not affect the risk of HIV disease progression. In general, women have a lower viral set-point than men. The viral set-point is the point at which HIV replication slows and is suppressed by the body's white blood cells. However, this lower set-point does not appear to influence the rate of HIV disease progression.

Infection Route

It has been suggested that infection route (how the disease was transmitted) may impact the rate of HIV progression in patients. For instance, HIV can be spread by sexual contact with an infected person, by sharing needles/syringes with someone who is infected, through breastfeeding, during vaginal birth or, less commonly (and rare in countries where blood is screened for HIV antibodies), through transfusions with infected blood. However, research results are conflicting.

Some studies have found faster rates of disease progression among HIV-infected patients who were infected via blood transfusion. However these studies may not have considered the age of the blood transfusion recipients. Patients who are infected at an older age are more likely to experience a faster disease progression.

While it has also been suggested that patients who acquire the disease via injection-drug use are more likely to experience a faster disease progression, there is conflicting scientific evidence. More studies are necessary before any firm conclusions can be made.

Nutrition

According to several studies, patients who have deficient levels of vitamin A, vitamin B12, or zinc are more likely to experience a rapid decline of CD4 cell counts. This is because the body's white blood cells need sufficient levels of these vitamins in order to grow and maintain health.

Researchers believe that poor absorption of nutrients, diarrhea, and inadequate calorie and protein consumption contribute to HIV progression. For instance, researchers found that poor nutrition in Zambia was the best predictor of death in both HIV-negative and HIV-positive children.

Several studies have shown that multivitamin supplementation can slow the rate of HIV disease progression and death. However, HIV patients who have gastrointestinal problems may have a difficult time absorbing these essential vitamins into the bloodstream. Some HIV patients may need to take vitamins that are injected or in a form that will dissolve in the mouth and be absorbed across the mucus membranes.

Pregnancy

The majority of studies suggest that pregnancy does not increase the rate of HIV disease progression. However, there is scientific evidence that the patient's viral load (number of HIV viral particles in the blood) increases gradually from delivery until 12 weeks after delivery, even in women receiving consistent antiretroviral therapy.

Recreational Drug Use

The majority of studies suggest that recreational drug use does not play a role in HIV disease progression. However, some studies are contradictory.

According to one study involving nearly 1,150 HIV-positive women (40% of whom used cocaine, heroin, methadone, or injection-drugs), there appears to be no association between drug use and CD4 cell percentage, viral loads, or death (of any cause). However, HIV patients who used drugs were more likely to develop other infections, especially herpes, tuberculosis, and recurrent pneumonia. Patients who develop these infections may then have an increased risk of progressing to AIDS.

Alcohol: Alcohol abuse appears to be prevalent among HIV patients. One study found that 41% of HIV-infected patients met the criteria for alcoholism, as defined by a score of five or higher on the Michigan Alcoholism Screening Test (MAST) survey. Recent studies have shown that HIV-infected patients with a history of alcohol problems, who are receiving highly active antiretroviral therapy (HAART) and are currently drinking, have greater HIV progression than those who do not drink.

In vitro studies suggest that Alcohol may block a chemical messenger in the immune system and stimulate the expression of CCR5 co-receptor, which HIV uses to infect cells. This in turn may lead to increased rates of HIV replication. However, human studies have not shown an association between alcohol consumption and HIV progression.

Cocaine: Cocaine use may affect HIV disease progression either directly or indirectly. Some studies have suggested that cocaine may increase the rate of HIV replication and suppress cytokines (chemical messenger that stimulate the immune response). These factors may enable HIV to infect more immune system cells.

Inhaled nitrates (poppers): It has been suggested that inhaled nitrates (poppers) may suppress the immune system. However, human and animal studies that have evaluated this association have produced inconclusive results. Further research is necessary to fully understand the relationship between inhaled nitrates and HIV.

Injection-drug use: Some researchers believe that DNA damage caused by injection-drug use may result in faster HIV replication and greater potential for viral mutations. This may ultimately lead to an increased risk of developing neurological diseases and resistance to antiretroviral drugs. However, more research is necessary to verify these claims.

HIV patients sharing needles may re-expose themselves to HIV, which may increase the rate of HIV disease progression. These patients also have an increased risk of developing other infections.

Marijuana: Marijuana may aggravate symptoms of HIV-induced mental impairment, especially memory loss, in patients who have advanced HIV.

Methamphetamine (meth): Methamphetamine (meth) may increase the risk of HIV disease progression. According to the results of one study, methamphetamine users who were receiving antiretroviral therapy (ART) were more likely to have higher viral loads than non-users. However, there appeared to be no significant difference in methamphetamine users who did not receive antiretroviral therapy. The researchers concluded that the impact on viral load may be the result of poor treatment adherence rather than a direct affect of the drug.

Researchers have found that both methamphetamine abuse and HIV infection may cause impaired cognitive (mental) functions. Patients may experience difficulties learning new information, solving problems, concentrating and quickly processing information. The researchers suggest that methamphetamine abuse and HIV infection significantly reduce the size of certain brain structures, which may be associated with impaired cognitive functions. Co-occurring methamphetamine abuse and HIV infection has shown to cause a greater impairment than each condition alone.

Repeated Exposure To Hiv

There is some scientific evidence suggesting that repeated exposure to HIV increases the rate of HIV disease progression.

One study involving 937 HIV-infected men who received little or no antiretroviral therapy found that the patients who had unprotected receptive anal intercourse experienced more rapid declines in their CD4 cell counts than men who did not engage in unprotected sex. The men who reported having unprotected sex in the last year were twice as likely to experience a CD4 cell drop as those who did not. The researchers found that the more people the patient had unprotected, receptive anal sex with, the greater the risk of CD4 cell count decline. However, the researchers could not determine whether the CD4 cell count decrease was the result of re-infection with HIV or exposure to other sexually transmitted infections or diseases.

Smoking

The majority of studies suggest that smoking does not influence the rate of HIV disease progression. However, there is good scientific evidence that HIV patients who smoke tobacco are more likely to develop certain opportunistic infections and diseases. Opportunistic infections occur in individuals who have weakened immune systems.

Candidiasis (thrush): In general, smokers are more likely to develop a yeast infection of the mouth called oral candidiasis (thrush) than non-smokers. More research is necessary to determine whether the same is true for HIV-positive patients.

One study found that even though smoking increased the amount of Candida albicans (yeast that causes the disease) in the mouths of HIV patients, it did not appear to increase the risk of developing thrush.

Another study found that smoking increased the risk of developing thrush, bacterial pneumonia, and another mouth infection called oral hairy leukoplakia in HIV-positive men. Patients who smoked the most had the greatest risk of developing these infections.

Emphysema: In addition, smokers who have HIV are more likely to develop emphysema than non-smokers. Emphysema is a chronic lung disease characterized by shortness of breath. Researchers conducted a study involving HIV-positive and HIV-negative people who smoked for 12 years or more. The researchers found that 37% of the HIV-positive patients showed evidence of emphysema, while none of the HIV-negative patients had signs or symptoms of the disease. HIV-positive patients also had higher levels of cytotoxic CD8 T-cells in their lungs tissues indicating that these immune cells may have caused some of the lung damage.

Kidney disease: Some research suggests that HIV patients who smoke are more likely to develop kidney disease than those who do not.

Lung cancer: HIV patients who smoke tobacco are more likely to develop lung cancer than HIV patients who do not. This is because the smoke contains more than 4,000 different chemicals and many of these chemicals have been shown to be cancer-causing substances.

Lung infection: Smokers typically have slightly higher CD4 cell counts than non-smokers. However, analyses of immune cells in the lung fluid show that the CD4 and CD8 percentages and cytokine activity are significantly lower in smokers than non-smokers. Therefore, smokers have an increased risk of developing lung infections. For instance, a review of 598 HIV patients found that smokers were three times more likely to develop Pneumocystis jiroveci pneumonia (formerly called Pneumocystis carinii pneumonia or PCP) than non-smokers. Patients who smoked the most were at the greatest risk of developing lung infections.

Smoking and pregnancy: HIV-infected pregnant women who smoke may have a greater chance of transmitting the disease to their babies during vaginal delivery, according to one study. However, the study was conducted between 1988 and 1990, before antiretroviral therapy was introduced as a treatment during pregnancy. Currently, antiretroviral therapy is given to pregnant women to reduce the risk of passing the disease. One-third of the patients who smoked in the study transmitted HIV to their babies, compared to less than one-fourth of women who did not smoke. Researchers have suggested that nicotine may cause the membranes surrounding the fetus to rupture prematurely, which increases the time the infant may be exposed to HIV-infected blood during delivery.

Stress

According to researchers, severe stress can increase the rate of HIV disease progression. Patients who had severe and frequent stress over a two-year period were four times more likely to experience HIV disease progression, according to one study. However, levels of stress that are common to everyday life did not affect the rate of disease progression.

In addition, psychological distress has also shown to increase the rate of HIV disease progression, but did not lead to a shorter survival time, according to one cohort study. The researchers concluded that patients who experienced psychological distress were more likely to develop an AIDS-defining illness within two years. When HIV patients develop an AIDS-defining illness, this means their condition has progressed to AIDS.