of Pulmonary Medicine,2 Henry Ford Hospital, Detroit, Michigan. Received 11 ... on the natural history of infection in women versus that in men, and confficting ...
JOURNAL OF CLINICAL MICROBIOLOGY, Apr. 1996, p. 970–972 0095-1137/96/$04.0010 Copyright q 1996, American Society for Microbiology
Vol. 34, No. 4
Gender Is Not a Factor in Serum Human Immunodeficiency Virus Type 1 RNA Levels in Patients with Viremia CHARLENE E. BUSH,1* RICHARD M. DONOVAN,1 NORMAN MARKOWITZ,1 DWAYNE BAXA,1 PAUL KVALE,2 AND LOUIS D. SARAVOLATZ1 Division of Infectious Diseases, Department of Internal Medicine,1 and Department of Pulmonary Medicine,2 Henry Ford Hospital, Detroit, Michigan Received 11 September 1995/Returned for modification 7 November 1995/Accepted 16 January 1996
We investigated gender as a factor in viral load measurements for human immunodeficiency virus-infected patients. Forty antiretroviral-therapy-naive, age- and CD4-matched women and men were tested for serum RNA and p24 antigen levels prior to antiretroviral therapy and at approximately 12 weeks after therapy. No gender differences were observed for these two markers of viral load.
either ddC or ddI. Blood samples were processed within 24 h of being obtained. Serum was separated from the cell fraction by centrifugation at 3,000 3 g for 5 min and then frozen in 1.0-ml aliquots at 2708C until tested for serum HIV RNA and p24 antigen concentrations. Serum samples from patients were tested for HIV type 1 (HIV-1) immune complex-dissociated p24 antigen by using a commercial assay kit (Coulter Corp., Hialeah, Fla.). Briefly, 100 ml of serum was treated with 100 ml of glycine (pH 1.85) for 90 min at 378C. The solution was neutralized with 100 ml of Tris buffer (pH 8.0) before being assayed for the p24 antigen concentration. The HIV-1 p24 antigen enzyme immunoassay was performed by using the Coulter HIV-1 p24 antigen kinetic standard according to the manufacturer’s instructions. The results were obtained as colorimetric optical density changes per unit of time and analyzed by using SOFT max version 2.01 software. Determinations for an individual patient were performed in duplicate in the same assay. Patient serum samples were assayed for HIV RNA by using the quantitative branched-chain DNA kit as directed by the manufacturer (Quantiplex HIV-RNA assay; Chiron Corp., Emeryville, Calif.) (6). Briefly, patient serum samples were thawed on ice and 1.0-ml samples were centrifuged at 23,500 3 g for 1 h at 48C to pellet the virus. Patient viral RNA pellets were resuspended in lysis buffer and incubated at 538C for 20 min. Clarified samples were incubated for 18 h in an enzymelinked immunosorbent assay format with HIV-specific probes labeled with alkaline phosphatase. Plates were washed, and quantification was based on the detection of a chemiluminescent signal. The lower limit of this assay was approximately 104 RNA copies per ml of serum. Figure 1 shows the HIV RNA data for serum samples from all patients with detectable serum HIV RNA levels. HIV RNA was detectable in 14 of 20 women and 17 of 20 men. Prior to the start of antiretroviral therapy, the median HIV RNA level was 49,000 copies for women (mean 6 standard error [SE]) 5 132,000 6 48,000) and the median HIV RNA level was 102,000 copies for men (mean 6 95% confidence interval 5 273,000 6 164,000) (P 5 0.36 by the Mann-Whitney U test). Among women, there was no significant difference between transmission category and serum HIV RNA level. In agreement with previous studies (7, 8), there was a statistically significant negative correlation between the HIV RNA and CD4 levels in serum (Spearman rank correlation coefficient 5 20.46 [P 5
The recent epidemiological pattern of human immunodeficiency virus (HIV) infection reveals a worldwide shift to a growing proportion of women (1). There is little information on the natural history of infection in women versus that in men, and conflicting studies of the progression of disease between the sexes have been reported (2, 7). Gender differences in the opportunistic infections experienced by HIV-infected individuals have also been reported (3). It is clear that in adult HIV-infected patients, increased viral burden is associated with the level of immune deficiency and in the case of pregnancy, the enhanced transmission of virus to the fetus (5). Because clinical trials and therapeutic decisions are starting to be made on the basis of viral load, we examined two markers of viral load in HIV-infected men and women with lower CD4 counts to determine if there was a gender-associated difference. Twenty antiretroviral-therapy-naive, HIV-infected women with a median age of 38 years (range, 23 to 58 years) and 20 men with a median age of 37.5 years (range, 18 to 53 years) enrolled in a study of pulmonary complications of HIV infection at Henry Ford Hospital were studied. Men and women were individually matched for age and CD4 count. This sample size was chosen to allow for an 80% chance of detecting a twofold difference in viral load between men and women. Eight women and three men became infected with HIV through injecting drugs; all other patients acquired the disease sexually. The median CD4 count for women was 212 cells per ml (range, 27 to 366 cells per ml), and the median count for men was 210 cells per ml (range, 34 to 357 cells per ml). Peripheral blood samples were collected by venipuncture from the 40 study patients prior to the start of antiretroviral therapy and at 8 to 12 weeks after the start of therapy. Eighteen of the women received zidovudine (ZDV) monotherapy, and the other two who were on a blinded study received ZDV alone or in combination with either dideoxycytidine (ddC) or dideoxyinosine (ddI). Fifteen of the men received ZDV monotherapy, two received ddI monotherapy, and three who were on a blinded study received ZDV alone or in combination with
* Corresponding author. Mailing address: Infectious Disease Research Laboratory, 7069 E & R Building, Henry Ford Hospital, 2799 W. Grand Blvd., Detroit, MI 48202. Phone: (313) 876-9412. Fax: (313) 876-2993. 970
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FIG. 1. Quantification by branched-chain DNA assay of serum HIV RNA levels in age- and CD4-matched women and men naive to antiretroviral therapy prior to and 12 weeks after the start of therapy.
FIG. 2. Quantification of serum HIV p24 antigen levels in age- and CD4matched women and men naive to antiretroviral therapy prior to and 12 weeks after the start of therapy.
0.046] for women and 20.67 [P 5 0.003] for men) prior to the start of antiretroviral therapy. With the initiation of therapy, the serum HIV RNA level dropped in 12 of 14 women and rose in 2. The serum HIV RNA level dropped in 16 of 17 men and rose in 2 (one man who had undetectable levels of RNA prior to therapy became positive after therapy). The median HIV RNA level posttherapy was 6,000 copies for women (mean 6 SE 5 36,000 6 17,000) and 15,500 copies for men (mean 6 SE 5 43,000 6 18,000) (P 5 0.65 by the Mann-Whitney U test). The median drop in serum HIV RNA level was 86% in women and 84% in men. Figure 2 shows the HIV p24 antigen data for serum samples from all patients with detectable serum HIV p24 antigen levels. HIV p24 antigen was detectable in 19 of 20 women and 18 of 20 men. Prior to the start of antiretroviral therapy, the median HIV p24 antigen level was 146 pg/ml for women (mean 6 SE 5 251 6 66) and 90 pg/ml for men (mean 6 SE 5 199 6 59) (P 5 0.65 by the Mann-Whitney U test). After antiretroviral therapy, the median p24 antigen level was 37 pg/ml for women and 24 pg/ml for men (P 5 0.44 by the Mann-Whitney U test). The median drop in serum HIV p24 antigen level was 63% in women and 67% in men. Prior to the start of antiretroviral therapy, there was a statistically significant correlation between the p24 antigen and RNA levels in serum (Spearman rank correlation coefficient 5 0.66 [P 5 0.004] for women and 0.55 [P 5 0.016] for men). This
correlation weakened for both men and women posttherapy (Spearman rank correlation coefficient 5 0.21 [P 5 0.35] for women and 0.34 [P 5 0.13] for men). In conclusion, no difference in either initial HIV RNA or p24 antigen level, posttherapy HIV RNA or p24 antigen level, or degree of change in these two markers with the initiation of antiretroviral nucleoside therapy could be demonstrated between women and men in this patient population. The importance of this observation is that for HIV-infected individuals, gender is not a factor in viral load levels that would compound therapeutic decisions based on viral loads in women. This work was supported in part by NHLBI/NIH Pulmonary AIDS Complications (PACs) grant R01-HL48511-01. REFERENCES 1. Centers for Disease Control and Prevention. 1995. Update: AIDS among women—United States. Morbid. Mortal. Weekly Rep. 44:81–84. 2. Friedland, G. H., B. Saltzman, J. Vileno, K. Freeman, L. K. Schrager, and J. W. Klein. 1991. Survival differences in patients with AIDS. J. Acquired Immune Defic. Syndr. 4:144–153. 3. Greenberg, A. E., P. A. Thomas, S. H. Landesman, D. Mildvan, M. Seidlin, G. H. Friedland, R. Holzman, B. Starrett, J. Braun, E. L. Bryan, and R. F. Evans. 1992. The spectrum of HIV-1 related disease among outpatients in New York City. AIDS 6:849–859. 4. Mellors, J. W., L. A. Kingsley, C. R. Rinaldo, J. A. Todd, B. S. Hoo, R. P. Kokka, and P. Gupra. 1995. Quantitation of HIV-1 RNA in plasma predicts outcome after seroconversion. Ann. Intern. Med. 122:573–579.
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J. CLIN. MICROBIOL. Barcherini, R. Bucciardini, and S. Mariotti. 1995. Effect of sex, age and transmission category on the progression to AIDS and survival of zidovudinetreated symptomatic patients. AIDS 9:51–56. 8. Verhofstede, V., S. Reniers, F. Van Wanzeele, and F. Plum. 1994. Evaluation of proviral copy number and plasma RNA level as early indicators of progression in HIV infection: correlation with virological and immunological markers of disease. AIDS 8:1421–1427.
