Tõnu Krispin

CCL3L1 Copy Number Is a Strong Genetic Determinant of HIV Seropositivity in Caucasian Intravenous Drug Users

BACKGROUND A high copy number of CCL3L1, the most potent human immunodeficiency virus (HIV)-suppressive chemokine, associates with reduced HIV susceptibility. Whether CCL3L1 influences acquisition of multiple blood-borne infections (eg, hepatitis C virus [HCV], HIV, and hepatitis B virus [HBV] infections), which occur commonly among injection drug users (IDUs), is unknown. METHODS We determined CCL3L1 copy number by real-time polymerase chain reaction among 374 Caucasian IDUs from Estonia; 285 were HCV positive, 208 were HIV positive, 177 were HCV and HIV positive, and 57 were HCV and HIV negative. RESULTS In univariate and multivariate analyses, HCV and HBV seropositivity and duration of IDU each strongly predicted HIV seropositivity. A high CCL3L1 copy number (>2) was associated with an 80% reduced risk of acquiring HIV infection after adjusting for age, sex, HCV and HBV status, CCR5-Delta32 polymorphism, and IDU duration (odds ratio, 0.20; 95% confidence interval, 0.09-0.45). By contrast, CCL3L1 gene dose did not influence HCV seropositivity. Among HCV-positive IDUs, there was a 3.5-fold overrepresentation and 65% underrepresentation of a high CCL3L1 copy number among HCV-positive, HIV-negative subjects and HCV-positive, HIV-positive subjects, respectively. CONCLUSION Among IDUs with extensive exposure to HCV and HIV, CCL3L1 copy number is a major determinant of HIV seropositivity but not of HCV seropositivity. The contrasting distribution of a protective high CCL3L1 copy number among HCV-positive, HIV-negative IDUs versus HCV-positive, HIV-positive IDUs may reflect that HIV preferentially selects for subjects with a low CCL3L1 gene dose.

Absence of genotypic drug resistance and presence of several naturally occurring polymorphisms of human immunodeficiency virus-1 CRF06_cpx in treatment-naive patients in Estonia.

All non‐B HIV‐1 subtypes and circulating recombinant forms (CRFs) are characterized by several polymorphisms in protease (PR) region. In addition, in recent years the increasing use of antiretroviral treatment (ART) has rapidly raised the spread of transmitted drug resistance. We aimed to determine the presence of naturally occurring polymorphisms and transmitted drug resistance mutations (DRMs) in ART naïve HIV‐1‐positive subjects in Estonia. A total of 115 drug‐naive HIV‐1‐infected subjects (mean age 27 years; 70% male; 65% infected via intravenous drug use and 34% by heterosexual contact) were enrolled. Viral genomic RNA from plasma was directly sequenced in PR, revertase (RT), and envelope (env) regions. Phylogenetic analysis of RT and env regions revealed that 89% and 3% of sequenced viruses belonged to CRF06_cpx and subtype A1, respectively, and 6% were described as unique recombinants (signed A1‐06) between CRF06_cpx and subtype A1 viruses. No primary DRMs were found in PR or RT regions indicating the absence of transmitted drug resistance. The most common polymorphisms in the PR region were K14R, M36I, H69K, and L89M seen in 96%, 100%, 99%, and 100%, respectively. The clinical relevance of these polymorphisms in terms of success of ART has to be monitored in future clinical studies. J. Med. Virol. 81:953–958, 2009.

Emerging transmitted drug resistance in treatment-naïve human immunodeficiency virus-1 CRF06_cpx-infected patients in Estonia.

Abstract Human immunodeficiency virus (HIV)-1 transmitted drug resistance in the drug-naïve population is of growing relevance in Estonia, where the number of antiretroviral (ARV) treatment-experienced subjects has been exponentially increasing during the last 10 y. The aim of this study was to estimate the rate of transmitted drug resistance among newly diagnosed subjects in Estonia in 2008. Genotypic resistance testing for viral genomic RNA was conducted for 201 subjects tested HIV-positive between 1 April and 30 November 2008. Of 145 genotyped viral strains in newly diagnosed patients, 123 were CRF06_cpx, 2 were subtype A1 and 3 were subtype B; in 17 cases viral sequences revealed recombinant structures similar to CRF06_cpx, subtype A1 and CRF02_AG. Resistance mutations were found in 8 (5.5%) virus strains, and 3 strains were resistant to at least 2 ARV classes. A total of 2.8% of sequences harboured mutations indicating nucleoside/nucleotide reverse transcriptase inhibitor resistance (M41L, M184V, M184I, T215C and T215D), 2.1% non-nucleoside reverse transcriptase inhibitor resistance (K103N, P225H) and 2.8% protease inhibitor resistance (M46I, L90M). These data suggest the need to extend genotypic HIV-1 drug resistance testing to newly diagnosed HIV-positive subjects to prevent potential ARV treatment failure.

Characterization of Integrase Region Polymorphisms in HIV Type 1 CRF06_cpx Viruses in Treatment-Naive Patients in Estonia

Natural polymorphisms of HIV-1, often associated with drug resistance, are widely described in protease and reverse transcriptase regions but data on their presence in the integrase region, especially in non-B subtypes, are still very limited. We aimed to characterize naturally occurring polymorphisms in the integrase region in 104 treatment-naive and 10 treatment-experienced patients infected predominantly with HIV-1 CRF06_cpx and its recombinant with subtype A1 and/or CRF03_AB viruses. No primary drug resistance mutations against integrase inhibitors were found, but resistance-associated polymorphisms such as V72I, L74I, V201I, and T206S were seen in more than 90% of viruses. Substitutions E157Q and E157K, associated with raltegravir resistance, were found in only two CRF06_cpx strains. We conclude that similar to other HIV-1 non-B subtypes, the CRF06_cpx and its recombinants with subtype A1 and CRF03_AB are rich in integrase region natural polymorphisms, which may impact the development of resistance against integrase inhibitors.

CCR5 haplotypes influence HCV serostatus in Caucasian intravenous drug users.

Background Up to 90% HIV-1 positive intravenous drug users (IDUs) are co-infected with HCV. Although best recognized for its function as a major co-receptor for cell entry of HIV, CC chemokine receptor 5 (CCR5) has also been implicated in the pathogenesis of HCV infection. Here, we investigated whether CCR5 haplotypes influence HIV-1 and HCV seropositivity among 373 Caucasian IDUs from Estonia. Methods Of these IDUs, 56% and 44% were HIV and HCV seropositive, respectively, and 47% were coinfected. 500 blood donors seronegative for HIV and HCV were also evaluated. CCR5 haplotypes (HHA to HHG*2) were derived after genotyping nine CCR2–CCR5 polymorphisms. The association between CCR5 haplotypes with HIV and/or HCV seropositivity was determined using logistic regression analysis. Co-variates included in the models were length of intravenous drug use, HBV serostatus and copy number of CCL3L1, the gene encoding the most potent HIV-suppressive chemokine and ligand for CCR5. Results Compared to IDUs seronegative for both HCV and HIV (HCV−/HIV-), IDUs who were HCV+/HIV- and HCV+/HIV+were 92% and 82%, respectively, less likely to possess the CCR5-HHG*1 haplotype, after controlling for co-variates (Padjusted = 1.89×10−4 and 0.003, respectively). This association was mostly due to subjects bearing the CCR5 HHE and HHG*1 haplotype pairs. Approximately 25% and<10% of HCV−/HIV- IDUs and HCV−/HIV- blood donors, respectively, possessed the HHE/HHG*1 genotype. Conclusions Our findings suggest that HHG*1-bearing CCR5 genotypes influence HCV seropositivity in a group of Caucasian IDUs.