High frequency of drug resistance mutations in human immunodeficiency virus type 1-infected Korean patients treated with HAART

Antiviral Potential of the Genus Panax: An updated review on their effects and underlying mechanism of action

Viral infections are known as one of the major factors causing death. Ginseng is a medicinal plant that demonstrated a wide range of antiviral potential, and saponins are the major bioactive ingredients in the genus Panax with vast therapeutic potential. Studies focusing on the antiviral activity of the genus Panax plant-derived agents (extracts and saponins) and their mechanisms were identified and summarized, including contributions mainly from January 2016 until January 2022. P. ginseng, P. notoginseng, and P. quinquefolius were included in the review as valuable medicinal herbs against infections with 14 types of viruses. Reports from 9 extracts and 12 bioactive saponins were included, with 6 types of protopanaxadiol (PPD) ginsenosides and 6 types of protopanaxatriol (PPT) ginsenosides. The mechanisms mainly involved the inhibition of viral attachment and replication, the modulation of immune response by regulating signaling pathways, including the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, cystathionine γ-lyase (CSE)/hydrogen sulfide (H₂S) pathway, phosphoinositide-dependent kinase-1 (PDK1)/ protein kinase B (Akt) signaling pathway, c-Jun N-terminal kinase (JNK)/activator protein-1 (AP-1) pathway, and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway. This review includes detailed information about the mentioned antiviral effects of the genus Panax extracts and saponins in vitro and in vivo, and in human clinical trials, which provides a scientific basis for ginseng as an adjunctive therapeutic drug or nutraceutical.

Korea HIV/AIDS Cohort Study: study design and baseline characteristics

The number of persons infected by HIV/AIDS has consistently increased in Korea since the first case of HIV/AIDS infection in 1985 and reached 15,208 by 2016. About 1,100 new patients with HIV/ AIDS infections have emerged every year since 2013. In Korea, the Korea HIV/AIDS Cohort Study was established for the evidenced-based prevention, treatment, and effective management of patients infected with human immunodeficiency virus (HIV) in December 2006. This study monitored 1,438 patients, who accounted for about 10% of all patients with HIV/AIDS in Korea, for 10 years with the following aims: (1) to develop an administrative system for the establishment of a HIV/AIDS cohort-based study; (2) to standardize methodologies and the case report forms; and (3) to standardize multi-cohort data and develop a data cleaning method. This study aims to monitor at least 1,000 patients (excluding those for whom investigation had been completed) per year (estimated number of patients who can be monitored by January 2018: 939). By December 2016, the sex distribution was 93.3% for men, and 6.7% for women (gender ratio, 13.9:1.0), and 98.9% of all participants were Korean. More than 50.0% of the participants were confirmed as HIV positive after 2006. This study reports competitive, long-term research that aimed to develop policies for the prevention of chronic infectious diseases for patients with HIV. The data collected over the last decade will be used to develop indices for HIV treatment and health promotion.

Effect of Korean Red Ginseng intake on the survival duration of human immunodeficiency virus type 1 patients

Background

Long-term ginseng intake can increase longevity in healthy individuals. Here, we examined if long-term treatment with Panax ginseng Meyer (Korean Red Ginseng, KRG) can also enhance survival duration (SD) in patients with human immunodeficiency virus type 1 (HIV-1) infection.

Methods

We retrospectively analyzed 252 HIV-1 patients diagnosed from 1986 to 2013 prior to the initiation of antiretroviral therapy. Overall, 162 patients were treated with KRG (3,947 ± 4,943 g) for 86 ± 63 mo. The effects of KRG on SD were analyzed according to the KRG intake level and the length of the follow-up period.

Results

There were significant correlations between the total amount of KRG and SD in the KRG intake group (r = 0.64, p < 0.0001) as well as between total amount of KRG and mean annual decrease in CD4⁺ T-cell count in all 252 patients (r = −0.17, p < 0.01). The annual decrease in CD4⁺ T-cell count (change in cells/μL) was significantly slower in KRG-treated patients than in patients receiving no KRG (48 ± 40 vs. 106 ± 162; p < 0.001). The SD (in months) was also significantly longer in the KRG group than in the no-KRG group (101 ± 64 vs. 59 ± 40, p < 0.01).

Conclusion

KRG prolongs survival in HIV-1 patients, possibly by slowing the decrease in CD4⁺ T-cell count.

The trend of transmitted drug resistance in newly diagnosed antiretroviral-naive HIV/AIDS patients during 1999-2012 in South Korea

BACKGROUND

The use of antiretroviral drugs has reduced the mortality and morbidity of patients with HIV/AIDS. More than 20 antiretroviral drugs have been used in patients with HIV/AIDS since zidovudine was first introduced in 1991 in South Korea.

OBJECTIVES

To investigate and estimate the annual prevalence of transmitted drug resistance and drug-resistant variants of HIV-1 in newly diagnosed antiretroviral-naive patients in South Korea during 1999-2012.

STUDY DESIGN

Plasma specimens were collected from 928 antiretroviral-naive patients during 1999-2012. Mutations in the protease and reverse transcriptase sections of the HIV-1 pol gene were identified using the Stanford HIV Drug Resistance Database (Stanford DB).

RESULTS

Among 928 HIV-1 isolates from antiretroviral-naive patients, 45 (4.8%) showed 'intermediate' or 'resistant' drug resistance. The predicted prevalence of drug resistance among isolates was 2.2%, 2.7%, and 0.3% for resistance to nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, and protease inhibitors, respectively.

CONCLUSIONS

There was no significant increase in the prevalence of drug resistance among antiretroviral-naive patients infected with HIV-1 during 1999-2012 in South Korea, although there was a slight increase during 2009-2012. The emergence of drug-resistant variants will continue to be monitored by national surveys.

Long-term follow up of HIV-1-infected Korean haemophiliacs, after infection from a common source of virus

In the early 1990s, 20 haemophiliacs (HPs) were infected with a common source of HIV-1 viruses through the contaminated clotting factor IX. The aim of this study is to review 20 HPs infected with a common source of virus. The enrolled patients have been consecutively treated with Korean red ginseng (KRG), zidovudine (ZDV) or two-drug therapy and highly active antiretroviral therapy (HAART). We determined full-length pol gene over 20 years and human leukocyte antigen (HLA) class I with peripheral blood mononuclear cells and reviewed medical records. Eighteen HPs experienced various opportunistic infections or clinical manifestations. There were significant inverse correlations between the HLA prognostic score and the annual decrease in CD4+ T-cell counts prior to HAART (AD) (P < 0.05) and the amount of KRG and the AD (P < 0.01). From 1998, the HPs had been treated with HAART. Each of the two patients died without and with HAART regimen respectively. At present, 16 HPs have been alive with HAART. Among the 16 HPs, 12 and 4 are on HAART-plus-KRG and HAART only respectively. Eleven HPs including 2 HPs with G-to-A hypermutations had revealed resistance mutations. Ten and two HPs have shown poor adherence and incomplete viral suppres-sion on HAART respectively. Virological failure based on WHO guidelines was not observed on KRG-plus-HAART. Two HPs revealed additional resistance mutations against two classes on KRG-plus-HAART. As a nationwide study, we first report overall features on clinical course of Korean haemophiliacs. Further education on the importance of drug adherence is needed.

The prevalence of antiretroviral multidrug resistance in highly active antiretroviral therapy-treated patients with HIV/AIDS between 2004 and 2009 in South Korea

BACKGROUND

Highly active antiretroviral therapy (HAART) including protease inhibitors (PIs) has been used in South Korea since 1997. Currently, more than 20 types of antiretroviral drugs are used in the treatment of human immunodeficiency virus-infected/acquired immune deficiency syndrome patients in South Korea. Despite the rapid development of various antiretroviral drugs, many drug-resistant variants have been reported after initiating HAART, and the efficiency of HAART is limited by these variants.

OBJECTIVES

To investigate and estimate the annual antiretroviral drug resistance and prevalence of antiretroviral multi-class drug resistance in Korean patients with experience of treatment.

STUDY DESIGN

The amplified HIV-1 pol gene in 535 patients requested for genotypic drug resistance testing from 2004 to 2009 by the Korea Centers for Disease Control and Prevention was sequenced and analyzed annually and totally. The prevalence of antiretroviral drug resistance was estimated based on "SIR" interpretation of the Stanford sequence database.

RESULTS

Of viruses derived from 787 specimens, 380 samples (48.3%) showed at least one drug class-related resistance. Predicted NRTI drug resistance was highest at 41.9%. NNRTI showed 27.2% resistance with 23.3% for PI. The percent of annual drug resistance showed similar pattern and slightly declined except 2004 and 2005. The prevalence of multi-class drug resistance against each drug class was: NRTI/NNRTI/PI, 9.8%; NRTI/PI, 21.9%; NNRTI/PI, 10.4%; and NRTI/NNRTI, 21.5%.

CONCLUSIONS

About 50% and less than 10% of patients infected with HIV-1 have multidrug and multiclass resistance linked to 16 antiretroviral drugs, respectively. The significance of this study lies in its larger-scale examination of the prevalence of drug-resistant variants and multidrug resistance in HAART-experienced patients in South Korea.

Monitoring HIV viral load in resource limited settings: still a matter of debate?

Introduction

Consequences of lack of viral monitoring in predicting the effects of development of HIV drug resistance mutations during HAART in resource-limited settings (RLS) is still a matter of debate.

Design

To assess, among HIV+ patients receiving their first-line HAART, prevalence of virological failure and genotypic resistance mutations pattern in a Médécins Sans Frontières/Ministry of Health programme in Busia District (Kenya).

Methods

Patients with HAART treatment for ≥12 months were eligible for the study and those with HIV-RNA ≥5000 copies/ml underwent genotypic study. Total HIV-1 RNA from Dried Blood Spots was extracted using Nuclisens method.

Results

926 patients were included. Among 274 (29.6%) patients with detectable viral load, 55 (5.9%) experienced treatment failure (viral load >5.000 copies/ml); 61.8% were female and 10 (18.2%) had clinical failure. Median CD4 cell count was 116 cell/mm3 (IQR: 54–189). Median HIV-RNA was 32,000 copies/ml (IQR: 11000–68000). Eighteen out of 55 (33%) samples could be sequenced on PR and RT genes, with resistance associated mutations (RAMs) in 15 out of 18 samples (83%). Among patients carrying RAMs, 12/15 (81%) harboured RAMs associated to thymidine analogues (TAMs). All of them (100%) showed M184V resistance associated mutation to lamivudine as well as NNRTI's RAMS.

Conclusions

Virological failure rate in resource-limited settings are similar to those observed in developed countries. Resistance mutation patterns were concordant with HAART received by failing patients. Long term detectable viral load confers greater probability of developing resistance and as a consequence, making difficult to find out a cost-effective subsequent treatment regimen.

Phylogenetic analysis of full-length pol gene from Korean hemophiliacs and plasma donors infected with Korean subclade B of HIV type 1

There was an outbreak of HIV-1 transmission among 20 out of 122 Korean hemophiliacs from 1990. We assessed the genetic relationships among HIV-1 viruses found in three cash-paid plasma donors whose preseroconversion plasma was used to produce Korean-made clotting factor, 20 hemophiliacs infected with HIV-1 in Korea, three hemophiliacs infected with HIV-1 from clotting factor manufactured outside Korea, and 71 local control patients infected with the Korean subclade of HIV-1 subtype B (KSB). Full-length pol gene sequences (2841 bp) of viruses from frozen stored serum, samples obtained 1-3 years after diagnosis, were amplified by RT-PCR and sequenced by direct DNA sequencing. Phylogenetic and signature pattern analyses were used to investigate the relationships among the sequences. Donors O and P were associated with two clusters, of 8 and 12 hemophiliacs, respectively, which were demarcated from the 71 KSB-infected local control patients and donor R. These data confirm that HIV-1 transmission to 20 hemophiliacs occurred through infusion of Korean-made clotting factor.

Drug susceptibility of human immunodeficiency virus type 1-derived pseudoviruses from treatment-experienced patients to protease inhibitors and reverse transcriptase inhibitors, using a modified single-round assay

BACKGROUND

Genotypic drug resistance assay has been the only method available to provide information related to drug resistance in South Korea since 1999. Phenotypic assay is also a useful method to predict a patient's state related to antiretroviral drug resistance. However, commercial systems and methods for phenotyping have not been introduced into South Korea.

OBJECTIVES

To establish and apply modified phenotypic drug susceptibility assay using treatment-experienced patients' derived HIV-1 in South Korea.

STUDY DESIGN

The genotypic drug resistance and phenotypic drug susceptibility of two different methods, Stanford HIV Drug Resistance Database (Stanford DB) and modified phenotypic drug susceptibility assay were compared especially focused on the HIV-1 protease (PR) and reverse transcriptase (RT) sequences.

RESULTS

There was some discordance in comparing drug susceptibility results (a modified drug susceptibility assay) with the predicted genotypic drug resistance (Stanford DB). Phenotypic drug resistance showed the following order for pseudoviruses from treatment-experienced patients infected with HIV/AIDS: Efavirenz (EFV, 21 to 1,319-fold change), Lamivudine (3TC, 31 to >189-fold change), Indinavir sulfate (IDV, 26 to 63-fold change), Amprenavir (APV, 4 to 35-fold change) and Zidovudine (AZT, 20 to 634-fold change). For patient KRC3221, the AZT-related phenotypic drug resistance was the greatest, with 634-fold change compared with the wild type.

CONCLUSIONS

Application of this modified phenotypic drug susceptibility assay is expected to help in predicting drug resistance as a guideline for clinicians to obtain a combined interpretation among genotyping, phenotyping and effective clinical treatments.

Antiretroviral genotypic resistance mutations in HIV-1 infected Korean patients with virologic failure

Resistance assays are useful in guiding decisions for patients experiencing virologic failure (VF) during highly-active antiretroviral therapy (HAART). We investigated antiretroviral resistance mutations in 41 Korean human immunodeficiency virus type 1 (HIV-1) infected patients with VF and observed immunologic/virologic response 6 months after HAART regimen change. Mean HAART duration prior to resistance assay was 45.3+/-27.5 months and commonly prescribed HAART regimens were zidovudine/lamivudine/nelfinavir (22.0%) and zidovudine/lamivudine/efavirenz (19.5%). Forty patients (97.6%) revealed intermediate to high-level resistance to equal or more than 2 antiretroviral drugs among prescribed HAART regimen. M184V/I mutation was observed in 36 patients (87.7%) followed by T215Y/F (41.5%) and M46I/L (34%). Six months after resistance assay and HAART regimen change, median CD4+ T cell count increased from 168 cells/microL (interquartile range [IQR], 62-253) to 276 cells/microL (IQR, 153-381) and log viral load decreased from 4.65 copies/mL (IQR, 4.18-5.00) to 1.91 copies/mL (IQR, 1.10-3.60) (P<0.001 for both values). The number of patients who accomplished viral load <400 copies/mL was 26 (63.4%) at 6 months follow-up. In conclusion, many Korean HIV-1 infected patients with VF are harboring strains with multiple resistance mutations and immunologic/virologic parameters are improved significantly after genotypic resistance assay and HAART regimen change.

Patient Characteristics and Treatment Outcome Associated with Protease Inhibitor (PI) use in the Asia-Pacific Region

OBJECTIVES: Regimens containing protease inhibitors (PI) are less commonly used in developing countries due to high cost and less availability. We evaluated characteristics of patients initiating PI-based therapy according to previous antiretroviral (ARV) exposure; factors associated with initiating a PI-containing regimen using newer versus older PIs, and proportion of patients with detectable viral loads (VL) after initiating a PI-based regimen. METHODS: This analysis includes all patients who have initiated a PI-based regimen. ARV exposure was categorised: naïve (no previous ARV), 1st, 2nd, >/= 3rd switches; a switch was defined as starting or stopping any drug in a regimen. Newer PIs were defined as those approved by the US FDA after 1 January 2000. Detectable VL at 12 months was defined as VL >/= 400 copies/mL. Characteristics at PI initiation were evaluated. Logistic regression was used to determine factors associated with initiating a newer PI and detectable VL at 12 months after PI initiation. RESULTS: 1106 patients initiated PI-based therapy; of these, 618 (56%) were naïve patients. Overall, 22% (176) of patients had detectable VL at 12 months following the PI initiation. Being from a high income country (vs. mid/low income, OR = 1.80, p = 0.034) were more likely to be associated with detectable VL. CONCLUSION: The use of PIs in this cohort is dictated by accessibility and affordability issues particularly for the newer PIs. Short-term virological outcomes following PI-therapy in our cohort were good, and were associated with CD4 count at time of initiation.

Beneficial effects of a combination of Korean red ginseng and highly active antiretroviral therapy in human immunodeficiency virus type 1-infected patients

To determine whether Korean red ginseng (KRG) has beneficial effects on human immunodeficiency virus type 1 (HIV-1)-infected patients administered highly active antiretroviral therapy (HAART), we analyzed the CD4 T-cell count, viral load, and resistance mutations to HAART in 46 individuals. Thirteen patients harbored resistance mutations at baseline. The study population was divided into two groups: specifically, a group treated with a combination of HAART plus KRG (23 patients) and a group treated with HAART alone (23 patients). The annual increase in CD4 T-cell count in the combination group was significantly higher than that in the group treated with HAART alone (P < 0.05). Overall, 21 patients harbored resistance mutations after 3 years of therapy. Following exclusion of 13 patients displaying baseline resistance mutations, 7.1% of patients (1/14) in the combination group and 42.1% (8/19) in the HAART group were identified with resistance mutations. One patient with baseline resistance mutations in the combination group did not display resistance mutations 3 years after HAART therapy. High-level resistance mutations were significantly lower in the combination group than in the group treated with HAART alone. Five patients showed no improvement in viral copy number (26.3% [5/19]) in the combination group and 9 (45.0% [9/20]) showed no improvement in the HAART-only group. Our data support the clinical utility of KRG intake during HAART therapy.

The public health approach to identify antiretroviral therapy failure: high-level nucleoside reverse transcriptase inhibitor resistance among Malawians failing first-line antiretroviral therapy

BACKGROUND

Over 150,000 Malawians have started antiretroviral therapy (ART), in which first-line therapy is stavudine/lamivudine/nevirapine. We evaluated drug resistance patterns among patients failing first-line ART on the basis of clinical or immunological criteria in Lilongwe and Blantyre, Malawi.

METHODS

Patients meeting the definition of ART failure (new or progressive stage 4 condition, CD4 cell count decline more than 30%, CD4 cell count less than that before treatment) from January 2006 to July 2007 were evaluated. Among those with HIV RNA of more than 1000 copies/ml, genotyping was performed. For complex genotype patterns, phenotyping was performed.

RESULTS

Ninety-six confirmed ART failure patients were identified. Median (interquartile range) CD4 cell count, log10 HIV-1 RNA, and duration on ART were 68 cells/microl (23-174), 4.72 copies/ml (4.26-5.16), and 36.5 months (26.6-49.8), respectively. Ninety-three percent of samples had nonnucleoside reverse transcriptase inhibitor mutations, and 81% had the M184V mutation. The most frequent pattern included M184V and nonnucleoside reverse transcriptase inhibitor mutations along with at least one thymidine analog mutation (56%). Twenty-three percent of patients acquired the K70E or K65R mutations associated with tenofovir resistance; 17% of the patients had pan-nucleoside resistance that corresponded to K65R or K70E and additional resistance mutations, most commonly the 151 complex. Emergence of the K65R and K70E mutations was associated with CD4 cell count of less than 100 cells/microl (odds ratio 6.1) and inversely with the use of zidovudine (odds ratio 0.18). Phenotypic susceptibility data indicated that the nucleoside reverse transcriptase inhibitor backbone with the highest activity for subsequent therapy was zidovudine/lamivudine/tenofovir, followed by lamivudine/tenofovir, and then abacavir/didanosine.

CONCLUSION

When clinical and CD4 cell count criteria are used to monitor first-line ART failure, extensive nucleoside reverse transcriptase inhibitor and nonnucleoside reverse transcriptase inhibitor resistance emerges, with most patients having resistance profiles that markedly compromise the activity of second-line ART.

High frequency of gross deletions in 5' LTR/gag and nef genes in patients infected with CRF02_AG of HIV type 1 who survived for over 20 years: an association with Korean red ginseng

Abstract We have shown that Korean red ginseng (KRG) intake is associated with gross deletions in the 5' LTR/gag (gDeltaLTR/gag) and nef genes (gDeltanef) of patients infected with subtype B of HIV-1. Here, we investigated these effects in three long-term survivors (LTSs) of subtype CRF02_AG of HIV-1. The three LTSs were diagnosed with HIV in 1987, 1988, and 1989, and have been treated with KRG for 7-15 years. Thirty-two samples of peripheral blood mononuclear cells were obtained from the subjects and used to amplify the 5' LTR/gag and nef genes via nested PCR. We obtained 88 amplicons in 5' LTR/gag and 128 amplicons in nef. The frequency of gDeltaLTR/gag was significantly higher (37.5%) in three LTSs than in control patients (8.6%, p < 0.01). Eight amplicons (9.5%) contained premature stop codon(s) in the gDeltaLTR/gag in three LTSs. Fourteen of the 128 nef amplicons (10.9%) contained the gDeltanef, which was present in only two (7.7%) of the 26 amplicons from control subjects. Interestingly, gDeltanef was detected 7 years after the reinitiation of KRG intake in an LTS and, coincidently, CD4 T cell counts and CD4/CD8 ratios rapidly increased. These data indicate that long-term intake of KRG has the therapeutic potential to induce gross deletions in HIV-1.

Frequent gross deletion in the HIV type 1 nef gene in hemophiliacs treated with Korean Red Ginseng: inhibition of detection by highly active antiretroviral therapy

Twenty hemophiliacs were infected with Korean subclade B (KSB) of HIV-1 from two cash-paid plasma donors in Korea in 1990. Our previous studies revealed that Korean red ginseng (KRG) intake increases the frequency of gross deletion in the nef gene (gDeltanef). We investigated whether KRG and highly active antiretroviral therapy (HAART) affected the frequency of gDeltanef in the 20 hemophiliacs who share common characteristics of the HIV-1 source, mode of transmission, and infection time. Over a 10-year period, we obtained 522 nef amplicons by nested PCR using 172 samples of peripheral blood mononuclear cells. Of the 522 nef amplicons, 69 (13.2%) were gDeltanef. Despite a 2-fold higher monthly dose of KRG, the frequency of gDeltanef detection (3.2%) was significantly reduced during HAART compared with that prior to HAART (20.6%) (p < 0.001). gDeltanef was detected significantly more in patients treated with a monthly KRG intake of more than 60 g (26.8%) than in patients treated with a monthly KRG intake of less than 60 g (10.5%) (p < 0.05). These finding suggest that the frequency of gDeltanef is dependent on the amount of KRG intake, although further study is needed. These data might provide a new perspective on the pathogenesis of HIV-1.

National survey for drug-resistant variants in newly diagnosed antiretroviral drug-naive patients with HIV/AIDS in South Korea: 1999-2005

We investigated the prevalence of drug-resistant variants and assessed their severity against antiretroviral drugs among patients in South Korea. Three hundred antiretroviral drug-naive patients were collected and drug-resistant variants were analyzed using the Stanford database with sequences and mutation data of the HIV-1 genes for protease (codons 1-99) and reverse transcriptase (codons 1-250). Of this group, 199 isolates (66.3%) showed at least 1 or more sites related to drug resistance. However, the average prevalence of drug resistance for patients newly diagnosed with HIV-1 but still treatment-naive between 1999 and 2005 was very low (4.3%, by "SIR" interpretation) compared with other countries. Most of the newly infected patients carried HIV subtype B (96%, n = 288) based on phylogenetic analysis of the conserved pol region. In summary, there has been no significant increase in the prevalence of drug resistance among antiretroviral drug-naive patients infected with HIV-1 for the last 7 years in South Korea. This study is quite significant regarding its larger scale of prevalence study for drug-resistant variants comparing to other drug-resistant studies using small scale of populations in South Korea. It is also important to provide suitable guidelines of genotyping assays for Korean drug-naive patients.

High frequency of gross deletions in the 5' LTR and gag regions in HIV type 1-infected long-term survivors treated with Korean red ginseng

Our previous studies have shown that gross deletions in the nef gene as well as slow decreases in CD4 T cell numbers are associated with Korean red ginseng (KRG) intake in HIV-1-infected patients. To determine whether there might be an association between KRG intake and occurrence of gross deletions (gDelta) in the 5' LTR and gag regions, we examined the 1125 base pair (bp) sequences encompassing these regions in 10 long-term survivors (LTSs) treated with KRG (total of 13,364 +/- 5364 g) for > 12 years, and in 8 LTS control patients with no or minimal (total of 1436 +/- 1027 g) KRG intake (LTS controls). In the 10 LTSs, 189 PCR products were obtained from 80 peripheral blood mononuclear cell (PBMC) samples. In total, 44 of the 80 PBMC samples (55%) and 71 of the 189 PCR products (37.6%) displayed gDelta. While 55% of PBMC samples and 37.6% of PCR products showed gDelta in the 10 LTSs, the corresponding figures for the eight LTS controls were 30.3% and 14.8%. These differences were significant (p < 0.05 and p = 0, respectively). In addition, the proportions of 28 patients in the general population (without KRG intake) displaying PBMC and PCR gDelta were 13.3% and 8.3%, respectively. Our data strongly suggest that gDelta occurrence in the HIV-1 5' LTR and gag regions is associated with KRG intake.