Vernazza PL, Eron JJ, Fiscus SA; International Conference on AIDS.
Int Conf AIDS. 1993 Jun 6-11; 9: 546 (abstract no. PO-B41-2469).
University of North Carolina, Chapel Hill.
OBJECTIVE: To study the role of freezing or time elapsed between phlebotomy and sample processing for HIV plasma cultures (cx). METHODS: 26 HIV-positive patients with a CD4 count lower than 300 have been recruited. Quantitative plasma cx were performed at 1, 4 and 24 hours after phlebotomy as well as after 1-4 months storage at -70 degrees C. 6 3-fold dilutions were cultured using the same method for all time points. All cx of one patient were set up with the same donor cells (except the cx of the frozen sample). Endpoint dilutions for each interval were compared with each patient's 1-hour cx (reference). A two-fold change in titer was considered to be significant. RESULTS: 17 patients (65%) had a positive plasma cx result at one hour, 14 of whom had a CD4 count less than 160. There was no correlation between CD4 count and virus titer. No cultures at 4 or 24 hours or after the freezing step gave a significant higher titer than the 1-h sample. Two samples at 4 and six at 24 hours had a significantly lower titer in the delayed culture (12% and 35% respectively). One subject with a positive culture at 1 hour had no detectable virus at 24 hour. No culture result after the freezing step was significantly different from the 1-hour reference value. The loss of virus titer over time was restricted to the patients with CD4 counts greater than 120. CONCLUSIONS: Plasma should not be stored longer than 2-4 hours for HIV culture. If immediate processing is not an option, plasma can be frozen shortly after phlebotomy for later batch testing without a significant loss of infectious virus.
Publication Types:
Keywords:
- CD4 Lymphocyte Count
- HIV Seropositivity
- Humans
- Immunologic Techniques
- Phlebotomy
- Plasma
- Time
- organization & administration
Other ID:
UI: 102205491
From Meeting Abstracts