Evaluation of two staging systems for HIV infection for use in developing countries

Objective: To evaluate the clinical axis of the World Health Organization (WHO) clinical staging system and the modified WHO staging system proposed by Montaner et al. using the lymphocyte strata > 1500, 1500-1000 and < 1000 cells x 10(6)/l.
Design: Cross-sectional study.
Patients: Four hundred and fifteen consecutive patients with HIV infection attending three HIV reference centres in Belgium.
Methods: Absolute CD4 lymphocyte counts were compared between stages within the two staging systems.
Results: Median CD4 lymphocyte counts decreased with increasing stage of disease in both staging systems. Differences in median CD4 lymphocyte counts between stages of each staging system were statistically significant (Kruskal-Wallis one-way analysis of variance, P < 0.001). The WHO clinical stage 1 and the modified WHO stage I had positive predictive values of 56 and 58%, respectively, for identifying patients with CD4 lymphocyte levels > 500 cells x 10(6)/l. The WHO clinical stage 4 and the modified WHO stage IV had positive predictive values of 79 and 80%, respectively, for identifying patients with CD4 lymphocyte levels < 200 cells x 10(6)/l.
Conclusions: The WHO clinical staging system or a modified version of this system using lymphocytes stratification may be a good alternative in developing countries to the CD4 lymphocyte count-based HIV staging system used in the developed world. Cohort studies in developing countries are needed to assess their prognostic value.
PIP: In 1990, Belgium, physicians enrolled 415 consecutive patients attending HIV reference centers in Antwerp, Brussels, and Ghent in a cross-sectional study designed to evaluate the clinical axis of the WHO staging system with and without the lymphocyte stratification proposed by Montaner el al. (that is, modified WHO staging system) (1500, 1500- 1000, and 1000 cells x 1 million/l). They filled in a standardized questionnaire with all criteria of the WHO staging system. Laboratory personnel used standard hematology and flow cytometry techniques to determine absolute and CD4 lymphocyte counts. 80% of the patients were Caucasians. 46% of all patients were homosexual and 42% were heterosexual; 79.2% were men. Median CD4 lymphocyte counts fell in both staging systems as the stage of HIV infection increased. There were significant differences in median CD4 counts between stages of each staging system (p .001). The modified WHO staging system's stage I was more sensitive at identifying patients with CD4 lymphocyte counts of more than 500 cells x 1 million/l than the WHO clinical stage 1 (83% sensitivity vs. 48% sensitivity). The positive predictive value of WHO clinical stage 4 and of the modified WHO staging system's stage IV for identifying people with CD4 lymphocyte counts of less than 200 cells x 1 million/l was quite high (79% and 80%, respectively). The researchers suggested that clinicians use stages 4 and IV as end-points is clinical trials in developing countries. Clinicians completing the questionnaire knew the patients' earlier CD4 lymphocyte count, which may have introduced a bias in the study. For example, they may have more thoroughly examined patients with low CD4 lymphocyte counts than those with normal counts. Nevertheless, the study's results indicated that either one of these systems may be a good alternative in developing countries to the technical equipment-dependent CD4 lymphocyte count-based HIV staging system used in developed countries. Cohort studies in developing countries would evaluate their prognostic value.

Publication year:1993

Keywords:HIV, Virology, AIDS, Viral diseases, Staging, CD4, Lymphocytes, Belgium, Europe-West

Accessibility:Closed