After a couple weeks on his HIV regimen, LZ developed a fever, blurred vision, and swelling around his eye. The odd thing was that his CD4 count had gone up dramatically since starting HIV medications. So what was going on? His immune system was better, yet his eye looked horrible. LZ was seen by his doctor and was diagnosed with immune reconstitution syndrome. What is immune reconstitution syndrome? It sounds good so why did LZ have another severe eye infection? Let's take a look at this odd syndrome and try to make some sense out of it. The first step is to understand the immune system.
Immune System BasicsThe body has a built in defense mechanism that fights off infection and illness; the immune system. The body's immune system is comprised of several types of cells and processes that recognize and fight foreign invaders such as bacteria, parasites and viruses. Unfortunately, in people infected with HIV, the immune system is damaged, making it more difficult for the body to fight off these infections. How can we tell how healthy the immune system is? The answer is simple; by measuring the number of specialized immune system cells known as the CD4 cell. The higher the CD4 count the stronger the immune system.
How Do We Know the Immune System is Working?When an infectious organism enters the body, a series of reactions occur that signal the immune system is working to fight off the infection. The reactions are collectively known as inflammation. Those inflammatory signs that the immune system is working include:
- swelling at the site of the injury or infection
- redness of the site
- thick drainage and discharge from the site of infection
- warmth and pain at the site
What Is Immune Reconstitution?Studies have shown that if HIV can be controlled by HIV medications, the immune system can repair itself. This immune rebuilding or reconstitution means that after repairing the damage done to the immune system, the body is better able to fight off those opportunistic infections that would otherwise make the person sick. As the HIV is controlled by medications, the body's CD4 count will rise, meaning the immune system is becoming stronger.
What is Immune Reconstitution Syndrome?Remember, if the body's immune system is damaged by HIV, the inflammatory process necessary for healing will not occur. That inflammatory process will return as the immune system is reconstituted. Take our example of LZ and his eye infection. Antibiotic treatment killed off much of the infectious organism responsible for the eye infection. Because LZ's immune system was damaged, the was no inflammatory process present; no redness, swelling, etc. When the HIV medications strengthened his immune system, the body sensed the remaining infectious organism in the eye, left behind after the antibiotic treatment was completed. Sensing the organisms, the newly reconstituted immune system triggered an inflammatory response, resulting in swelling, redness, discharge from the eye and fever. While LZ's immune system was healthier, his eye infection returned. This is the irony of immune reconstitution syndrome.
Is Immune Reconstitution Serious?
While immune reconstitution syndrome signals a healthier immune system, it can be a serious, sometimes fatal condition. Depending on the infection present, aggressive treatment is necessary to prevent serious illness. Common infections that occur during immune reconstitution include
What Can Be Done About Immune Reconstitution Syndrome?Again, reconstituting the immune system is a good thing and while that process is desirable, the infection and inflammatory process present in immune reconstitution syndrome must be addressed. Treatment can include:
- Continuation of the current HIV medication regimen.
- Antibiotic or antiviral medications to treat the infection.
- Steroids to temporarily suppress the inflammatory process.