Report of Cases.--CASE 1.--A 35-year-old heterosexual man contracted genital herpes simplex following vaginal intercourse with a prostitute. Three weeks later, he was tested for HIV at an anonymous testing center and told he was positive. Despondent, he did not return for results of a repeat test. Over 3 years, he sold most of his possessions, avoided dating, abstained from intercourse, ceased seeking to advance his career, and significantly increased his use of ethanol. The patient had a CD4 cell count of 0.87x109/L (869/microliters) on two occasions. He declined repeat HIV testing because he did not want the results known by his insurance company. At our center, HIV enzyme immunoassay (EIA) and Western blot (WB) were negative twice. Three months later, he reports resolution of dysphoria and ethanol abuse, renewed interest in his work, resumption of dating and protected vaginal intercourse, and adoption of a less materialistic, more prioritized approach to life.
CASE 2.--A 32-year-old homosexual man, while intoxicated, had unprotected receptive anal intercourse with a patient with the acquired immunodeficiency syndrome (AIDS). Two months later, he developed a febrile exanthem. His HIV EIA was negative four times over 1 year. Then, an anonymous testing center informed him that his EIA was positive and his WB was indeterminate. The CD4 cell count was 0.86x109/L (860/microliters). His insurer disclosed the HIV diagnosis and sexual orientation to his employer, upon which he was fired. Screening at our center twice revealed negative HIV EIA and WB results. Polymerase chain reaction (PCR) for HIV DNA was also negative. Three months later he remains convinced that "something must be wrong" due to persistent urticaria and an episode of antibiotic-associated thrush. He has undergone monthly HIV testing at different sites, where two HIV EIA/WB tests and one HIV PCR have been negative. He remains unemployed, celibate, and profoundly a! nxious.
Comment.--Potential explanations for inaccurate reports of HIV infection are numerous. Positive EIA and WB reactions have occurred following hepatitis B and influenza vaccinations and receipt of immune globulin products [1,2]. False-positive reactions can also result from patient antibody binding to HLA antigens that contaminate some test kits [3]. Specimens have been accidentally or intentionally mislabeled [4], and misinterpretation of indeterminate WB by health care workers has occurred.
Our patients exemplify the burden unnecessarily borne by a person who is erroneously diagnosed as HIV-infected. All patients with an indeterminate WB following an EIA-positive result for HIV infection must have repeat testing at 3 months as previously described [5]. Patients with an indeterminate WB test result should be questioned about recent immunization or receipt of immune globulin. Vigilance is especially necessary when a patient reports HIV infection but lacks documentation or appropriate follow-up evaluation, when the patient is asymptomatic and has normal T-lymphocyte populations, and when the patient has a low-risk profile for HIV infection.
REFERENCES
1. Lee DA, Eby WC, Molinaro GA. HIV false positivity after hepatitis B vaccination. Lancet. 1992;339:1060. [Medline Link] [Context Link]
2. MacKenzie WR, Davis JP, Peterson DE, Hibbard AJ, Becker G, Zarvan BS. Multiple false-positive serologic tests for HIV, HTLV-1, and hepatitis C following influenza vaccination, 1991. JAMA. 1992;268:1015-1017. [Context Link]
3. Dubey L, Gabel CA, Gershon A. HLA antigen contamination of commercial Western blot strips for detecting HIV. J Infect Dis. 1989;159:357-359. [Medline Link] [Context Link]
4. Gill MJ, Rachlis A, Anand C. Five cases of erroneously diagnosed HIV infection. Can Med Assoc J. 1991;145:1593-1595. [Medline Link] [Context Link]
5. Celum CL, Coombs RW, Lafferty W, et al. Indeterminate HIV-1 Western blots: seroconversion risk, specificity of supplemental tests, and an algorithm for evaluation. J Infect Dis. 1991;164:656-664. [Medline Link] [Context Link]