Transcript Document
44th ICAAC
ANTIRETROVIRAL TREATMENT HIGHLIGHTS
An HIV/AIDS Overview from the
44th Annual Interscience Conference on Antimicrobial Agents and Chemotherapy
October 30 - November 2, 2004; Washington, DC Summarized by
Douglas J. Ward, MD, FACP
Dupont Circle Physicians Group, Washington, DC
Supported by an unrestricted educational grant from
ANTIRETROVIRAL TREATMENT HIGHLIGHTS
44th
ICAAC
New Findings on:
Virologic Monitoring and Drug Resistance
Nucleoside/Nucleotide Reverse Transcriptase Inhibitor Options and Regimens for First- and Second-line Therapy
Simplification/Switch Strategies for Patients With Virologic Suppression
Current and Investigational Protease Inhibitors in First- and Second-line Therapy
CCR5 Antagonists and Viral Tropism
Virologic Monitoring and Drug Resistance
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Intermittent Low-Level HIV 1 Viremia (“Blips”) in
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Virologically Controlled Patients Viremic “blips” during antiretroviral therapy do not appear to result in evolution of resistant virus or virologic failure.
10 patients with HIV-1 RNA < 50 copies/mL for 11-79 months
• •
Viral loads measured 3 times weekly for 3-4 months Each test read by 2 independent labs
18 blips detected in 9 patients
•
Only 1 confirmed by both labs
No significant genotypic changes detected
No correlation found with any demographic, clinical, or treatment related factor
Viremic blips are common, do not predict treatment failure or development of resistance, and likely represent laboratory variation in the majority of cases.
Nettles RE, et al. 44th ICAAC, 2004. Abstract H-1134
.
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Frequency and Characteristics of the NRTI-Associated K65R and L74V/I RT Mutations Frequency of NRTI-Associated Mutations in 2003 (ViroLogic Database) M184V/I T215Y/F M41L D67N K219Q/E/N/R K70R L210W L74V/I K65R Y115F Q151M T69 ins 4% 2% 1% 1% 0 5 10 16% 15% 12% 20% 20% 15 20 25% 25 30 31% 35 40 % Genotypes (n > 16,000) 44% 45 50 McColl DJ, et al. 44th ICAAC, 2004. Poster H-178.
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Frequency and Characteristics of the NRTI-Associated K65R and L74V/I RT Mutations Phenotypic NRTI Susceptibility of HIV-1 Variants With K65R 100 100 94 98 100 99 87 87 80 78 71 60 40 20 0 ZDV (1.9) 29 38 17 15 4 4 d4T (1.7) TDF (1.4) ABC (4.5) NRTIs (PhenoSense cut-off) ddl (1.7) K65R + M184V McColl DJ, et al. 44th ICAAC, 2004. Poster H-178
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K65R + NAMs 0 1 3 3TC (3.5) K65R Alone www.medscape.com/hiv-aidshome
Frequency and Characteristics of the NRTI Associated K65R and L74V/I RT Mutations Phenotypic NRTI Susceptibility of HIV-1 Variants With L74V/I
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100 100 100 100 100 100 100 100 97 80 71 64 60 43 45 37 40 21 20 15 15 8 0 0 ZDV (1.9) d4T (1.7) TDF (1.4) ABC (4.5) NRTIs (PhenoSense cut-off) ddl (1.7) L74V/I + M184V McColl DJ, et al. 44th ICAAC, 2004. Poster H-178
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L74V/I + NAMs 3TC (3.5) L74V/I alone www.medscape.com/hiv-aidshome
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Predictors of K65R With Tenofovir in Antiretroviral
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Therapy (ART)-Experienced and -Naive Patients In patients taking tenofovir, emergence of the K65R drug resistance mutation was associated with the absence or presence of other specific regimen components.
258 ART-experienced and 37 ART-naive patients
•
median follow-up, 67 weeks
K65R developed in 29 (11%) ART-experienced persons
• •
28 had virologic failure No K65R in ART-naive persons
Taking triple-NRTI regimens including tenofovir increased risk of K65R
• •
Tenofovir/didanosine + lamivudine or emtricitabine Tenofovir/abacavir + lamivudine or emtricitabine
Taking tenofovir with zidovudine or lamivudine reduced risk of K65R Staszewski S, et al. 44th ICAAC, 2004. Poster H-177
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Prevalence of Transmitted HIV Drug Resistance in ART Naive Individuals in the United States in 2003 Proportion of Patients With Reduced Susceptibility to > 1 Drug (N = 317) Any ARV > 1 NRTI > 1 NNRTI 1 NNRTI 2 NNRTI 3 NNRTI > 1 PI 1 PI 2 PI 3 PI 0 0.9% 0.9% 0.3% 3% 4% 5 6% 6% 23% 18% 10% NRTI mutations: 15%
V118I (4%), D67N (1%), M41L (or mix, 1%) NNRTI mutations: 6%
K103N (3%), G190A (or mix, 1%), V108I (or mix, 1%) Primary PI mutations: 4%
None > 1% 10 % Subjects 15 20 25 Ross LL, et al. 44th ICAAC, 2004. Poster H-173.
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Nucleoside/Nucleotide Reverse Transcriptase Inhibitor Options and Regimens for First- and Second-line Therapy
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Trizivir + Tenofovir vs Combivir + Efavirenz in ART-Naive Patients A single-class, quadruple-NRTI regimen was shown to be equivalent to a standard, 2-class efavirenz based regimen for first-line therapy.
TIMS: 48-week randomized, open-label trial
113 ART-naive subjects were randomized to receive: Quad-NRTI (n=57) ZDV/3TC/ABC 300/150/300 mg BID + TDF 300 mg QD or Triple (n=56) ZDV/3TC 300/150 mg BID + Efavirenz 600 mg QD
Baseline characteristics were comparable, including: Median HIV RNA (log 10 copies/mL) Median CD4+ (cells/mcL) 5.26
194 5.13
153 Moyle G, et al. 44th ICAAC, 2004. Abstract H-1131.
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Trizivir + Tenofovir vs Combivir + Efavirenz in ART-Naive Patients Proportion of Subjects With HIV-1 RNA <50 Copies/mL Through Week 48 (ITT, M=F) 100 80 60 68 % 67 % 40 20 EFV+ZDV/3TC Quad-NRT I 0
0 4 8 12 24 Treatment Time (Weeks) 1 virologic failure (Quad-NRTI) 36 48
Total cholesterol decreased significantly in Quad-NRTI arm: -0.2 mmol/L vs +0.8 mmol/L (P <.001) ITT , intention-to-treat analysis; M=F, missing equals failure Moyle G, et al. 44th ICAAC, 2004. Abstract H-1131
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Trizivir + Tenofovir in ART-Naive Subjects: COL40263 Proportion of Subjects With HIV-1 RNA <50 Copies/mL at Week 24
27 subjects (22%) discontinued study 100 85
12 (9.8%) due to adverse events 80 60 54 71 65 46 61
9 (8%) had grade 3/4 lab abnormalities 40 20
8 (7%) had suspected ABC hypersensitivity 0 Overall No of Subjects ITT M=F AT BL VL <100,000 ITT M=F Overall 123 94 AT <100,000 52 40 BL VL > 100,000 >100,000 71 54
Reductions in lipids were observed
8 virologic nonresponders
•
>1 TAMs only, 3
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>1 TAMs+M184V, 3
•
Wild-type, 2 ITT, intention-to-treat analysis; M=F, missing equals failure; AT, as treated DeJesus E, et al. 44th ICAAC, 2004. Poster H-564.
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Trizivir + Tenofovir in Patients With Early Virologic
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Failure on Initial Regimen: ESS30005 Zidovudine/lamivudine/abacavir (Trizivir) + tenofovir may be a viable rescue option for patients with early virologic failure on a standard initial regimen.
ESS30005: Open-label study
51 patients with early virologic failure (VL >400 but <10,000 copies/mL)
•
Failing regimens: zidovudine (or stavudine)/lamivudine + PI or NNRTI
Baseline characteristics:
•
Median HIV-1 RNA: 3.3 log 10 copies/mL (68% <5000 copies/mL)
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Median CD4+ cell count: 436 cells/mcL (37% > 350 cells/mcL)
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< 2 NRTI mutations: M184V (82%), TAMs (24%), no K65R
43 patients (84%) completed > 24 weeks of follow-up Rodriguez AE, et al. 44th ICAAC, 2004. Poster H-563.
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Trizivir + Tenofovir in Patients With Early Virologic
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Failure on Initial Regimen: ESS30005 Proportion of Subjects With HIV-1 RNA <50 Copies/mL Through Week 24 100 80 60 40 93% 80% 75% 65% 20 0 0 4 8 12 16 Treatment Time (Weeks) 20 Obs <400 Obs <50 ITT M=F <400 ITT, intention-to-treat analysis; M=F, missing equals failure; Obs, observed analysis Rodriguez AE, et al. 44th ICAAC, 2004. Poster H-563.
24 ITT M=F <50 www.medscape.com/hiv-aidshome
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Tenofovir/Emtricitabine + Efavirenz vs Combivir +
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Efavirenz in ART-Naive Patients Better overall responses were seen with tenofovir/emtricitabine than with zidovudine/lamivudine (Combivir) in the preliminary analysis of this head-to-head study.
Study 934: Open-label, randomized, noninferiority study
Planned 24-week analysis (96-week study)
ART-naive patients were randomized to receive: Tenofovir/Emtricitabine (n=255) TDF 300 mg + FTC 200 mg + EFV (all QD) or Combivir (n=254) ZDV/3TC 300/150 mg (BID) + EFV (QD)
Baseline characteristics were comparable, including: Median HIV RNA (log 10 copies/mL) % HIV RNA > 100,000 Median CD4+ (cells/mcL) % < 200 5.0
52 233 42 5.0
50 241 41 Gazzard B, et al. 44th ICAAC, 2004. Abstract H-1137c
.
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Tenofovir/Emtricitabine + Efavirenz vs Combivir +
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Efavirenz in ART-Naive Patients Time to Loss of Virologic Response (TLOVR) <50 Copies/mL (ITT) 100 80 60 40 20 0 0 4 8 16 Treatment Time (Weeks) TDF/FTC ZDV/3TC ITT, intention-to-treat analysis Gazzard B, et al. 44th ICAAC, 2004. Abstract H-1137c.
24 P = .038
73% 65% www.medscape.com/hiv-aidshome
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Tenofovir/Emtricitabine + Efavirenz vs Combivir +
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Efavirenz in ART-Naive Patients Patient Disposition Through Week 24 TDF/FTC ZDV/3TC Permanent Study Regimen Discontinuation (%) Adverse Event (%) Noncompliance/Lost Follow-up (%) Suboptimal Virologic Response (%) Other (%) 11 3 4 2 3
5% (vs 0% ) discontinued due to anemia in the Combivir arm 21 * 9 † 6 1 5 * P = .003 † P = .008
Significantly better overall response with tenofovir/emtricitabine due to fewer adverse events leading to fewer discontinuations in that arm
Gazzard B, et al. 44th ICAAC, 2004. Abstract H-1137c.
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Efficacy of Fixed-Dose Abacavir/Lamivudine +
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Efavirenz: ESS30009 Proportion of Subjects With HIV-1 RNA <50 Through Week 24 (ITT, M=F) 100 80 69% 60 40 ABC/3TC+EFV 20 Terminated ABC/3TC+TDF 0 0 4 8 12 16 Treatment Time (Weeks) 20 24
Abacavir/lamivudine + tenofovir stopped due to a 49% failure rate
•
Patients in that arm were assigned new regimens and followed
–
ABC/3TC/EFV (35%), ABC/3TC/TDF/ZDV (15%), ZDV/3TC/EFV (11%), ABC/3TC/ZDV/EFV (9%), TDF/3TC/ZDV/EFV (5%) ITT, intention-to-treat analysis; M=F, missing equals failure Gallant JE, et al. 44th ICAAC, 2004. Poster H-567.
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Efficacy of Subsequent Treatment of Tenofovir +
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Abacavir/Lamivudine Nonresponders: ESS30009 Virologic Response Following Switch to Second-line Regimens up to 12 Weeks 100 80 60 40 20 Obs <400 ITT M=F <400 Obs <50 ITT M=F <50 0 2 4 8 Treatment Time Post Switch (Weeks) 12
Predictors of a 12-week post-switch viral load < 50 copies/mL:
• •
Baseline viral load: OR, 0.163; P = .001
Abacavir use: OR, 7.731; P = .009
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Efavirenz use: OR, 5.797; P = .015
Zidovudine use: OR, 5.032; P = .022
ITT, intention-to-treat analysis; M=F, missing equals failure; Obs, observed Gallant JE, et al. 44th ICAAC, 2004. Poster H-567.
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Early Virologic Failure With Once-Daily Didanosine/Tenofovir/Efavirenz in ART-Naive Patients Didanosine/tenofovir/efavirenz, but not didanosine/lamivudine/efavirenz, was associated with poor virologic responses in patients with high viral loads and low CD4+ cell counts.
In an open-label trial, ART-naive individuals were randomized to receive:
• •
QD QD didanosine/tenofovir/efavirenz (n=41) didanosine/lamivudine/efavirenz (n=36)
The study was terminated after an unplanned analysis at week 12 n (%) with VL <50 copies/mL at week 12 n (%) with virologic failure through week 12 ddI/TDF/EFV 22 of 36 (61%) 5 of 41 (12%) ddI/3TC/EFV 24 of 34 (71%) 0 of 36 (0%)*
Drug-resistant virus emerged rapidly in first 4 virologic failures *P < .05
All 5 subjects with virologic failure had baseline VL >100,000 copies/mL and CD4+ cell count < 200 cells/mcL Moyle G, et al. 44th ICAAC, 2004. Poster H-566
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Tenofovir/Didanosine: Paradoxical CD4+ Cell Declines Despite Good Virologic Control The combined use of tenofovir + didanosine can cause CD4+ cell counts to fall, even as viral load goes down or remains undetectable.
Retrospective assessment: 570 patients were taking TDF/ddI, TDF, ddI, or neither agent
All subjects had HIV RNA <400 copies/mL for >1 year (N=570)
Paradoxical CD4+ cell decreases seen only with TDF/ddI
•
not observed with TDF or ddI individually or with other NRTI
CD4+ cell decreases were more common in patients:
• • •
who switched to TDF/ddI to simplify regimen on NRTI-only regimens that included TDF/ddI with longer exposure to higher doses of ddI
Median CD4+ cell decline of 385 cells/mcL among subjects who switched to a triple-NRTI regimen containing TDF/ddI
CD4+ cell decreases appeared after ~6 months of TDF/ddI and then increased in magnitude www.medscape.com/hiv-aidshome Barrios A, et al. 44th ICAAC, 2004. Abstract H-1132.
Simplification/Switch Strategies for Patients With Virologic Suppression
Switching From a PI- to a Once-Daily Efavirenz-
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Based Regimen: VEST-QD Once-daily efavirenz + didanosine/lamivudine appears to be a safe and effective option for virologically suppressed patients switching from a PI-based regimen.
VEST-QD: Interim results of an ongoing 48-week open-label trial
Patients with VL <50 copies/mL on PI regimens were randomized to:
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Efavirenz + didanosine/lamivudine (all QD)
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Efavirenz + current NRTIs (ZDV/3TC, 51%; d4T/3TC, 30%; other, 19%) Virologic Response at Week 24 (ITT NC=F): HIV RNA <400 copies/mL (%) HIV RNA <50 copies/mL (%) ddI/3TC (n=92) 89 85 Current NRTI (n=94) 90 87
1 virologic failure (current-NRTI arm)
HDL-C levels increased in both arms (P < .0001)
Adherence improved in both arms (P < .05)
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No difference between arms ITT, intention-to-treat analysis; NC=F, noncompletion equals failure Cohen C, et al. 44th ICAAC, 2004. Poster H-577
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Trizivir vs Combivir + Nevirapine in Patients With
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Virologic Suppression: SimplifiHAART Two PI-sparing simplification strategies for patients with virologic suppression appear to be comparably safe and effective, and associated with improvements in cholesterol levels.
SimplifiHAART: 48-week randomized, open-label switch study
134 patients with undetectable VL (not defined) for > 24 months were randomized to:
•
zidovudine/lamivudine/abacavir
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zidovudine/lamivudine + nevirapine
~90% were taking a PI-based regimen at baseline Results through week 48
13 (19%) and 14 (21%) subjects discontinued due to side effects
1 virologic failure in each arm ZDV/3TC/ABC (n=68) % Undetectable VL (ITT NC=F) % Undetectable VL (OT) ITT, intention-to-treat analysis; NC=F, noncompletion equals failure Bonjoch A, et al. 44th ICAAC, 2004. Poster H-562.
71 98.6
ZDV/3TC/NVP (n=66) 73 98.5
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Trizivir vs Combivir + Nevirapine in Patients With
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Virologic Suppression: SimplifiHAART Proportion of Patients with Elevated TC and LDL-C Levels at Baseline and Week 48 TC >5.2 mmol/L - Trizivir (%) LDL-C TC >3.36 mmol/L - Trizivir (%) TC >5.2 mmol/L - Combivir/nevirapine (%) LDL-C >3.36 mmol/L - Combivir/nevirapine (%) Baseline 55.6
60.0
68.9
59.3
Week 48 30.5
20.6
42.2
41.7
P
.019
.003
.019
NS Bonjoch A, et al. 44th ICAAC, 2004. Poster H-562.
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Favorable Lipid Changes With Switch From Stavudine to Tenofovir: GS903E Mean Changes in Fasting Lipid Parameters After d4T to TDF Switch 0 -10 -20 -30 -40 -50 -60 -70 TC -40*-38* LDL-C -23* -17* HDL-C LDL-C/HDL-C -0.2 -0.2
-6* -4* *P < .001
TG -62* -44* Week 12 (n=85) Week 24 (n=83)
85 patients substituted tenofovir for stavudine in rollover phase of GS903
No patient lost viral suppression (<50 copies/mL) through 24 weeks post-switch
No patient discontinued due to adverse events Suleiman JMAH, et al. 44th ICAAC, 2004. Poster H-158.
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Current and Investigational Protease Inhibitors
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Favorable Increases in HDL-Cholesterol With Fosamprenavir in ART-Naive Patients: NEAT In the NEAT study, treatment with unboosted fosamprenavir + abacavir/lamivudine was associated with increases in high-density lipoprotein cholesterol (HDL-C) levels.
Secondary analysis of the 48-week NEAT study
Randomized, open-label study in ART-naive patients, comparing:
• •
fosamprenavir 1400 mg + abacavir 300 mg/lamivudine 150 mg (n=166) nelfinavir 1250 mg + abacavir 300 mg/lamivudine 150 mg (n=83)
Baseline lipids were similar, with relatively low HDL-C, in both arms
HDL-C and other lipid changes were observed through week 48: Mean Change From Baseline at Week 48 Total cholesterol (TC) (%) HDL-C (%) TC/HDL-C ratio (%) Triglycerides (mg/dL) Fosamprenavir -1 +37 +31 +2 Nelfinavir +12 +22 +29 +46 Nadler JP, et al. 44th ICAAC, 2004. Poster H-156.
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Favorable Increases in HDL-Cholesterol With Fosamprenavir in ART-Naive Patients in the NEAT Study Increases in HDL-C to Maximum Post Baseline by NCEP Lipid Category 100% 80% 60% 40% 20% 0% Fosamprenavir (n=148) 27 27 Nelfinavir (n=72) 10 21 43 69 BL 49 24 Max. post BL 76 BL 47 Max. post BL <40 mg/dL >40 to <60 mg/dL >60 mg/dL Nadler JP, et al. 44th ICAAC, 2004. Poster H-156.
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Tipranavir/Ritonavir vs Other Boosted PIs in ART-
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Experienced Patients: RESIST-1 Following 24 weeks of treatment, tipranavir/ritonavir appeared to be superior to other boosted PIs in patients with PI-resistant virus.
RESIST-1: Randomized, controlled, open-label, phase 3 trial
Study participants had multiple PI experience and PI-resistant virus
• • •
failing a PI-containing regimen at entry
1 primary PI mutation 2 mutations at codon 33, 82, 84, or 90
620 patients were randomized to receive: Tipranavir (n=311) Tipranavir/ritonavir 500/200 mg + optimized background regimen or
36.1% of subjects received enfuvirtide Comparator PI (n=309) Comparator PI/ritonavir + optimized background regimen Hicks C, et al. 44th ICAAC, 2004. Abstract H-1137a.
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Tipranavir/Ritonavir vs Other Boosted PIs in ART-
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Experienced Patients: RESIST-1 Discontinuations and Adverse Events
More people discontinued a control PI than tipranavir, usually because of virologic failure: On treatment Discontinued
•
Virologic failure
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Adverse events Tipranavir (n=311) 263 48 13 25 Comparator PI (n=309) 151 139 109 9
Rates of grade 3/4 side effects were similar overall ( 22.8% and 18.1% ) but differed significantly for certain parameters: ALT elevation (%) Cholesterol (%) Triglycerides (%) 6.9
4.2
21.7
1.3 * 0* 12.5
† * P < .001 † P < .01
www.medscape.com/hiv-aidshome Hicks C, et al. 44th ICAAC, 2004. Abstract H-1137a
.
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Tipranavir/Ritonavir vs Other Boosted PIs in ART-
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Experienced Patients: RESIST-1 Virologic Responses at 24 Weeks (ITT, N=F) 60 40 *P < .001
20 34.7
*
25.1
*
0 Tipranavir < 400 copies/mL ITT, intention-to-treat analysis; N=F, noncompletion equals failure Hicks C, et al. 44th ICAAC, 2004. Abstract H-1137a.
*P < .001
16.5
*
10
*
Comparator PI < 50 copies/mL www.medscape.com/hiv-aidshome
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Tipranavir/Ritonavir vs Other Boosted PIs in ART-
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Experienced Patients: RESIST-1 Impact of Enfuvirtide (ENF) on Virologic Responses at 24 Weeks (ITT, N=F) 60 47.1
40 32.8
21.9
20 14.3
0 Tipranavir + ENF < 400 copies/mL ITT, intention-to-treat analysis; N=F, noncompletion equals failure Hicks C, et al. 44th ICAAC, 2004. Abstract H-1137a.
Comparator PI + ENF < 50 copies/mL www.medscape.com/hiv-aidshome
CCR5 Antagonists and Viral Tropism
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873140, a Novel CCR5 Antagonist: 10-Day Responses to Monotherapy Median Change in Viral Load at Day 10 by Dose Group Placebo (n=9) 200 QD (n=7) 200 BID (n=8) 400 QD (n=8) 600 BID (n=8) 0 -0.2
-0.4
-0.6
-0.8
-1 -1.2
-1.4
-1.6
-1.8
-0.12
-0.46
-1.23
-1.03
-1.66
21 ART-experienced, 19 ART-naive subjects
HIV RNA >5000 copies/mL, CD4+ >200 cells/mcL, CCR5-tropic virus at baseline
No serious adverse events in any treatment group Lalezari J, et al. 44th ICAAC, 2004. Abstract H-1137b.
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Distribution of Coreceptor Tropism According to
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Treatment Status Relative Distribution of HIV-1 Tropism Among ART-Naive and -Experienced Patients* 100 80 60 40 82 88 67 20 0 R5 n = 339 263 76 16 12 28 Total ART-Naive ART-Experienced 36 R5/X4 67 31 Tropism 2 6 0 X4 5 6 * Source = 442 stored samples from GlaxoSmithKline clinical trials; 412 successfully typed Demarest J, et al. 44th ICAAC, 2004. Abstract H-1136
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Distribution of Coreceptor Tropism According to CD4+ Cell Count Prevalence of R5- and X4/Dual-Tropic Isolates by Absolute CD4+ Cell Count* 100 80 60 40 40 60 41.9
58.1
14.8
85.2
16 84 16 84 X4 or R5/X4 R5 20 0 ( < 50 n=50) > 51-100 (n=31) > 101-200 (n=81) > 201-300 (n=104) CD4+ cell count (cells/mcL) > 300 (n=248) * Source = 865 stored samples, Chelsea and Westminster Hospital, London; 616 successfully typed Moyle G, et al. 44th ICAAC, 2004. Abstract H-1135
.
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