Cytomegalovirus 131

linings. This may be quite destructive, and occasionally leads to damage throughout the entire wall of the gut; it may cause perforation of the gastrointestinal tract.

Symptoms and physical findings of cytomegalo-virus vary from disease to disease. Symptoms of chorioRETiNiTis include unilateral visual field loss, blurring of vision, or scotomata. Examination generally reveals whitish areas with perivascular exu-dates and hemorrhages. A careful search of the entire fundus (base) of the eye is required. Generally, in gastrointestinal disease, colitis is associated with abdominal pain and diarrhea. Fever may also be present. esophagitis and gastritis most commonly present with pain from the involved structures. Endoscopy reveals erythema, submucosal hemorrhage, and diffuse mucosal ulceration. While CMV may be isolated from pulmonary secretions, it is generally believed that it rarely has a true pathologic role in HIV-infected patients. Diagnosis must be confirmed by lung biopsy demonstrating histologic evidence consistent with invasive disease. Finally, encephalitis, cranial nerve dysfunction, and neuropathies may occur. CMV polyradiculopathy is rare, but characterized by lower extremity weakness, numbness, and bladder dysfunction.

Rapid diagnosis of CMV disease may lead to improved survival. A variety of diagnostic methods have been attempted, but the most useful is microscopic examination of biopsy samples. CMV infection of human cells results in characteristic changes found in these biopsies. CMV-infected cells become enlarged with a so-called owl's-eye appearance; they are typically found in areas with considerable inflammation. Special tests, which involve such staining techniques as immunofluorescence and dna in situ hybridization may be used by experienced pathologists to confirm the presence of CMV cells. Newer procedures, such as POLYMERASE CHAIN REACTION (PCR), which identifies minute quantities of CMV DNA in body fluids and tissue samples, may be helpful. Culture of CMV from bodily fluids probably adds little diagnostic information. Use of radiographic techniques such as barium exams and ct scans may reveal defects in the esophagus, stomach, or intestines, but without biopsy of those lesions, diagnosis is uncertain, and treatment premature.

In the absence of therapy, CMV disease is progressive and is associated with a high mortality rate. Early treatment is essential and may alter the course of the disease, including its spread to other locations in the body. Treatment may also prevent severe consequences of CMV disease such as perforation and hemorrhage, which may result in death. The two most commonly used drug treatments for CMV infection are ganciclovir and fos-carnet. Both are approved by the United States food and drug administration. Both result in the suppression of CMV, but not elimination. Ganci-clovir has been shown to be effective in the treatment of both CMV esophagitis and colitis in patients infected with HIV, resulting in increased time until relapse and increased survival. Ganci-clovir causes adverse side effects that lead to discontinuation of therapy in about one third of patients. The most common adverse effects are on the bone marrow, resulting in a decrease in the number of neutrophils. Ganciclovir may also cause lowering of the platelet count, which can increase the risk of bleeding because of decreased clotting ability of the blood. The risk of toxicity is worsened when ganciclovir is given with AZT. Adverse reactions are decreased when either ddi or ddc are used instead of AZT. Other side effects include headaches, confusion, nausea, vomiting, diarrhea, and possibly testicular damage.

Foscarnet has also been found to be effective in treating CMV disease and appears to inhibit HIV as well. It is as effective as ganciclovir in the treatment of CMV gastrointestinal disease and can be used both in newly infected patients and in patients who have relapsed after therapy with ganciclovir. Foscarnet has a different side effect profile than ganciclovir. While foscarnet does not affect the bone marrow tissues, and therefore can be used concurrently with AZT, it does have a toxic effect on the kidneys that results in passage of excess electrolytes into the urine. Other adverse effects associated with foscarnet include nausea, vomiting, diarrhea, oral and penile ulceration, and seizures.

Standard treatment of CMV disease usually begins with several weeks of ganciclovir. If there is no elimination of the virus from biopsies taken during repeat endoscopy, or the patient continues to experience severe symptoms, he or she is

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