Bridging the Gap: Conference Record [Abstract book, International Conference on AIDS (12th: 1998: Geneva, Switzerland)]

12th World AIDS Conference

Abstracts 42181-42185 809

regeneration of CD4 cells. In 2 patients of group A the decrease of VL immediatly
after initiating of therapy persisted for 5 months and increasing of CD4 cell counts
were observed. After next 3 months of treatment although the increasing of VL
levels and CD4 is increase and clinical stage is stabilized. In all of 6 patients
of group B (3 asymptomatic and 3 AIDS patients) the decreasing of VL was
observed. In 3 AIDS patients the increase CD4 cell counts and improving of
clinical status were observed. In 2 patients CD4 cell counts decreased and in one
patient CD4 cell count was without significant changes as well as clinical stage of
these asymptomatic subjects. Both of two patients from group C remain clinicaly
stabilized (first with low and second with high number of RNA copies) although
of continualy being decreased counts of CD4 cells. The level of Ag HIV 1 ranged
between 0-26 pg/ml in all of 13 monitored patients, except of the first patient form
group C.
Conclusion: The changes of surrogate markers reflect the effect of antiretroviral therapy. The decrease of VL and improving of clinical status with no clear
correlation with CD4 counts were observed in all monitored patients.
42181 Plasma immune activation marker levels compare
favorably with and add to viral load and CD4 T cells as
prognostic indicators
John L. Fahey', J.M.G. Taylor2, B. Manna3, P. Nishanian2, N. Aziz2, J.V. Giorgi2,
R. Detels2. 1 Cirid at UCLA, Microbiology & Immunology, Box 951747, Los
Angeles, CA; 2UCLA School of Public Health, Los Angeles, CA, USA; 3Institute
of Cholera & Enteric Diseases, Calcutta, India
Objectives: To determine the advantages of plasma activation marker measurements vis-a-vis HIV viral load and CD4 levels for assessing HIV disease
course.
Design: A retrospective analysis was conducted of 3 major plasma activation
markers, the soluble TNF receptor II, neopterin and soluble IL-2 receptor levels,
and of CD4 T cell levels and plasma HIV viral load. The participants were 659
men seen at 6 month intervals in the UCLA MACS cohort who were seropositive
but AIDS-free in 1985. The outcome measure was clinically defined AIDS within
3 years. Failure time statistical regression models for the time to development of
AIDS were used to assess prognostic capacity of the parameters alone and in
combinations.
Results: (1) Plasma levels of sTNF-RII and other soluble markers of immune
activation were confirmed to have prognostic capabilities. (2) Plasma activation
marker levels were shown to be able to stratify patients for prognosis within all
the major categories of CD4 T cell levels and of HIV RNA levels. (3) Combination
of a plasma activation marker level with CD4 T cell levels improved prognostic
capability of each. (4) A new graphic technique presenting the precision of prediction (POP) was developed which allows ready comprehension of the prognostic
capability of surrogate markers and easy comparison.
Conclusions: CD4 number and sTNF-RII levels were better prognostic factors
than HIV level with advanced disease, e.g., CD4 - 200 mm3. Inexpensive tests
such as plasma sTNFu-RII or neopterin levels can be useful for evaluations of
HIV disease course, especially when expensive equipment, technical expertise
and funding required for flow cytometry and for HIV load measurements are not
readily available.
42182 CD4 T cells phenotyping by flow cytometry: A quality
assurance programme (QAP) for African settings
Philippe van de Perre1, Yves Traore1, P.C. Combe2, D.B. Bonard2, F.M. Mandy3,
L.G.C. Gautier-Charpentierl, S.D. Diagbouga', N.M. Meda1. 'Centre Muraz 01
BP153, Bobo-Dioulasso, Burkina-Faso; 2Cedres Abidjan, Cote D'lvoire;
3Laboratoire de Cytology Analytique, Ottawa, Canada
Introduction: T-cells sub-populations counts were measured in the context of
an ongoing clinical trial on prevention of mother to child transmission of HIV-1
in Bobo-Dioulasso, Burkina Faso and Abidjan, Ivory Coast. To assure good
concordance between the two centers, CeDRes, Abidjan and Centre Muraz,
Bobo-Dioulasso, a Quality Control (QC) was established.
Objectives: 1) To establish the feasability of CD4-T cells numeration quality
assurance programme (QAP) in two African countries. 2) To provide a framework
to erasure reproductibility, and precision of CD4+ lymphocytes measurement in
HIV-infected patients in the two countries.
Methods: Three times a year, blood samples on K3 EDTA were exchanged
between the two centers. CD3+/CD4+ and CD3+/CD8+ cells were measured
within 12 hours after drawing using a double plateform technology which includes
flow cytometry and hematology instruments.
Results: The six Qcs performed so far represented 104 samples and showed
very good correlation (.0.95) between the two laboratories for CD3+/CD4+ and
CD3+/CD8+ cells in terms of percentages and absolute counts. However some
dicordances were observed in few absolute counts due to the manual lymphocyte
determination.
Conclusion: This study showed that CD4-T cells QC is feasable. We propose
to extend QAP for T-cells count to five African countries using a single plateform

technology. This programme will be supported by the Laboratory of Analytical
Cytology (LAC). We expect this programme to help preparing African countries to
monitor their anti-retroviral-treated patients in a improved and well standardized
technology.

42183 1 CD45 activity in T cells: A new surrogate marker of HIV
disease
Antonello Giovannettil, G. Ricci', M. Pierdominici', F. Mazzetta', R. Paganelli',
F. Pandolfi2, F. Aiuti1. ' Chair of Clinical Immunology and Allergy, Viale Dell
'Universita' 371-00185 Roma; 2Chair of Semeiotica Medica UCSC, Rome, Italy
Background: Reduced lymphoproliferative response to anti-CD3 and increased
susceptibility of T cells to undergo spontaneous cell death have been described
as immune correlates of progressive impairment in HIV disease. CD45 tyrosine
phosphatase is required for signal transduction through the T cell receptor (TCR)
and can induce T and B cell apoptosis. Then we studied the activity of CD45 in
lymphocytes from HIV-infected asymptomatic subjects, long term non progressors
(LTnP) and in HIV seronegative normal donors.
Methods: CD45 associated tyrosine phosphatase activity was assayed on
immunopecipitates of both CD4 and CD8 cells from thirteen long term non progressors (LTnP), 16 age-matched, asymptomatic, normal progressor patients,
and 14 normal donors. Expression of surface antigens, anti CD3-mediated lymphoproliferation, detection of 32 bp deletion of CCR5 gene and viral load were
evaluated by standard techniques.
Results: CD4+ and CD8+ T cells from HIV-1 infected asymptomatic displayed a
significantly reduced CD45-associated PTPase activity as compared to LTnP and
normal donors. No difference were observed in CD45 expression. In contrast the
anti-CD3 induced lymphoproliferation was significantly inhibited in both progressors and, although for a lesser extent, in LTnP. We have also evaluated by PCR
the distribution of CCRD/wt. 30%of LTnP were found positive for 32 bp deletion
of CCR5 gene. This had no correlation with anti CD3 proliferative response or
CD45 phosphatase activity. Both spontaneous and Fas-induced apoptosis were
significantly increased in progressors patients, but not in LTnP. Interestingly we
observed that an inverse correlation could be found between: 1) spontaneous
apoptosis and CD45 phosphates activity; 2) CD45 driven enhancement of apoptosis and phosphatase activity; 3) Fas induced apoptosis and CD45 phosphatase
activity.
Conclusions: Impairment of CD45 activity is easily detected in HIV+ individuals with the exception of LTnP. It is inversely related to both spontaneous
and Fas mediated apoptosis, but not to anti CD3 proliferation. Then evaluation
of CD45 activity may represent an additional and useful tool to predict disease
progression.
42184 Modification of apoptosis during combination therapy
Franco Pandolfi', M. Pierdominicil, M. Marziali1, I. Mezzaromal, E. Pinter,
M.R. Rippo2, F. Aiuti1. Allergy& Clinical Immunology, Sapienza University, Viale
Dell 'Universita' 37 Rome; 2University of Rome Torvergata, Rome, Italy
Objectives: Spontaneous apoptosis is increased in HIV-disease and correlates
with disease severity and progression. We have previously shown that treatment
with reverse transcriptase inhibitors significantly reduce apoptosis measured
shortly after the beginning of treatment. We therefore evaluated the effect of
combination therapy on apoptosis.
Design: Apoptosis was evaluated in patients before and after the start of a
combination therapy (2 reverse transcriptase inhibitors plus indinavir).
Methods: Apoptosis was evaluated by flow cytometry. Presence of caspase
activity was measured by in vitro cleavage of their common substrate PARP
(poly-ADP-ribose-polymerase).
Results: Spontaneous apoptosis measured shortly after the beginning of
combination therapy (1-3 days), was significantly increased as compared to
pre-treatment levels. Apoptosis remained increased (but to a lesser extent) two
months after treatment was started and was still above the baseline values eight
months later in some patients. Increased levels of apoptosis were detected despite the early increase of absolute numbers of CD4 cells. Apoptosis occurred
in both CD4 and CD8 cells, but was not associated with early augmentation of
Fas bearing cells. Caspase activity was consistent with the levels of apoptosis
detected by flow cytometry. Supplementation of the cultures with IL-2 in vitro,
significantly reduced apoptosis in all tested conditions.
Conclusions: Despite rapid recovery of CD4 cells in patients with advanced
HIV-disease, combination therapy induce an early increase of spontaneous apoptosis on both CD4 and CD8 cells. This effect did not correlate with Fas expression
and could be reversed in part by the addition of IL-2 in vitro. These data suggest that combination therapy could induce mobilization of T-cells from lymphoid
tissues that could account for increased apoptosis.
|42185 Normal values for T-cell subsets in the Free State region
of South Africa
Marinde Kotzel, M. Steyn', M. Van der Westhuizen', J. Roodt', E. Van der
Ryst2. 1Dept. of Haematology (G2), 2Dept. of Virology (G23), PO Box 339, UFS,
Bloemfontein, South Africa
Introduction: Analysis of T-cell subsets is essential in the evaluation of the
clinical status of HIV/AIDS patients. However, the "normal" values for these mea
surements in individuals from developing countries are not known, and values
obtained from studies in developed countries, such as the Royal Free Hospital
study, are commonly used.
Objectives: To establish the normal values for T-cell subsets in the peripheral
blood of individuals from the Free State region of South Africa and to determine
whether these values are influenced by race or sex.