British HIV Association guidelines for the routine investigation and monitoring of adult HIV-1-infected individuals 2011

Pharmacological management of cardiovascular conditions and diabetes in older adults with HIV infection

This review looks at the evidence for potential and theoretical risks of combining antiretroviral treatment with drugs prescribed for cardiovascular disease and diabetes. These conditions are common in the HIV-infected population as a result of ageing and the increased risk associated with both HIV infection and antiretroviral intake.

Trends in clinical characteristics of HIV-infected patients initiating antiretroviral therapy in Shanghai from 2006 to 2011

This study aimed to characterise the clinical characteristics of HIV-infected patients accessing antiretroviral therapy (ART) in Shanghai, China, from 2006 to 2011. We retrospectively reviewed the records of patients who initiated ART in Shanghai during the 6-year period of 2006 through 2011. The median age at ART initiation decreased from 41 years in 2008 to 38 years in 2011. The median CD4 counts at ART initiation rose from 65 cells/mm(3)in 2006 to 203 cells/mm(3)in 2011. The proportion of patients with CD4 counts <200 cells/mm(3)at ART initiation decreased from 88.5% in 2006 to 49.6% in 2011. The proportion of patients starting stavudine-based regimens of stavudine/lamivudine/efavirenz and stavudine/lamivudine/nevirapine fell from 49.2% in 2006 to 23.4% in 2011. The proportion of patients starting nevirapine-based regimens of zidovudine/lamivudine/nevirapine and stavudine/lamivudine/nevirapine fell from 44.3% in 2006 to 16.5% in 2011. The study reflects that the clinical characteristics of the patients initiating ART in Shanghai have changed over time; ART was increasingly provided in patients with higher CD4 counts; and the regimens containing stavudine were prescribed less frequently. Strategies to facilitate early access to ART and further reduction in stavudine use are needed.

HIV and ageing: what the geriatrician needs to know

The transformation of human immunodeficiency virus (HIV) from a rapidly fatal disease to a chronic manageable illness has resulted in annual increases in the numbers of people living with HIV. The HIV cohort is therefore ageing, with numbers of older adults with HIV climbing, through both prolonged survival and late acquisition of the disease. Associated with ageing is an accumulation of HIV-associated non-AIDS related co-morbidities, creating a complex patient group affected by multi-morbidity along with polypharmacy, functional decline and complex social issues. With this in mind, this review seeks to explore areas where HIV (diagnosed or undetected) may impact on the work of clinical geriatricians.

Local phylogenetic analysis identifies distinct trends in transmitted HIV drug resistance: implications for public health interventions

BACKGROUND

HIV transmitted drug resistance (TDR) surveillance is usually conducted by sampling from a large population. However, overall TDR prevalence results may be inaccurate for many individual clinical setting. We analyzed HIV genotypes at a tertiary care setting in Ottawa, Ontario in order to evaluate local TDR patterns among sub-populations.

METHOD

Genotyping reports were digitized from ART naïve patients followed at the Immunodeficiency Clinic at the Ottawa Hospital, between 2008 and 2010. Quality controlled, digitized sequence data were assessed for TDR using the Stanford HIV Database. Patient characteristics were analyzed according to TDR patterns. Finally, a phylogenetic tree was constructed to elucidate the observed pattern of HIV TDR.

RESULTS

Among the 155 clinic patients there was no statistically significantly difference in demographics as compared to the Ontario provincial HIV population. The clinic prevalence of TDR was 12.3%; however, in contrast to the data from Ontario, TDR patterns were inverted with a 21% prevalence among MSM and 5.5% among IDU. Furthermore, nearly 80% of the observed TDR was a D67N/K219Q pattern with 87% of these infections arising from a distinct phylogenetic cluster.

CONCLUSIONS

Local patterns of TDR were distinct to what had been observed provincially. Phylogenetic analysis uncovered a cluster of related infections among MSM that appeared more likely to be recent infections. Results support a paradigm of routine local TDR surveillance to identify the sub-populations under care. Furthermore, the routine application of phylogenetic analysis in the TDR surveillance context provides insights into how best to target prevention strategies; and how to correctly measure outcomes.

Treatment for stable HIV patients in England: can we increase efficiency and improve patient care?

Objectives

To estimate the costs and potential efficiency gains of changing the frequency of clinic appointments and drug dispensing arrangements for stable HIV patients compared to the costs of hospital pharmacy dispensing and home delivery.

Methods

We estimated the annual costs per patient (HIV clinic visits and either first-line treatment or a common second-line regimen, with some patients switching to a second-line regimen during the year). The cost of three-, four- and six-monthly clinic appointments and drug supply was estimated assuming hospital dispensing (incurring value-added tax) and home delivery. Three-monthly appointments and hospital drug dispensing (baseline) were compared to other strategies.

Results

The baseline was the most costly option (£10,587 if first-line treatment and no switch to second-line regimen). Moving to six-monthly appointments and home delivery yielded savings of £1883 per patient annually. Assuming patients start on different regimens and may switch to second-line therapies, six-monthly appointments and three-monthly home delivery of drugs is the least expensive option and could result in nearly £2000 savings per patient. This translates to annual cost reduction of about £8 million for the estimated 4000 eligible patients not currently on home delivery in London, England.

Conclusions

Different appointment schedules and drug supply options should be considered for stable HIV patients based on efficiency gains. However, this should be assessed for individual patients to meet their needs, especially around adherence and patient support.

Low frequency of genotypic resistance in HIV-1-infected patients failing an atazanavir-containing regimen: a clinical cohort study

OBJECTIVES

To determine protease mutations that develop at viral failure for protease inhibitor (PI)-naive patients on a regimen containing the PI atazanavir.

METHODS

Resistance tests on patients failing atazanavir, conducted as part of routine clinical care in a multicentre observational study, were randomly matched by subtype to resistance tests from PI-naive controls to account for natural polymorphisms. Mutations from the consensus B sequence across the protease region were analysed for association and defined using the IAS-USA 2011 classification list.

RESULTS

Four hundred and five of 2528 (16%) patients failed therapy containing atazanavir as a first PI over a median (IQR) follow-up of 1.76 (0.84-3.15) years and 322 resistance tests were available for analysis. Recognized major atazanavir mutations were found in six atazanavir-experienced patients (P < 0.001), including I50L and N88S. The minor mutations most strongly associated with atazanavir experience were M36I, M46I, F53L, A71V, V82T and I85V (P < 0.05). Multiple novel mutations, I15S, L19T, K43T, L63P/V, K70Q, V77I and L89I/T/V, were also associated with atazanavir experience.

CONCLUSIONS

Viral failure on atazanavir-containing regimens was not common and major resistance mutations were rare, suggesting that adherence may be a major contributor to viral failure. Novel mutations were described that have not been previously documented.

Tracking the progress of HIV: the impact of point-of-care tests on antiretroviral therapy

It is now around 30 years since the discovery of HIV, the virus that causes AIDS. More than 70 million people have been infected in that time and around 35 million have died. The majority of those currently living with HIV/AIDS are in low- and middle-income countries, with sub-Saharan Africa bearing a disproportionate burden of the global disease. In high-income countries, the introduction of antiretroviral therapy (ART) has drastically reduced the morbidity and mortality associated with HIV. Patients on ART are now predicted to have near-normal life expectancy and the role of treatment is increasingly recognized in preventing new infections. In low- and middle-income countries, treatment is now more widely available and around half of those who need ART are currently receiving it. Early diagnosis of HIV is essential if ART is to be optimally implemented. Lab-based diagnostics for screening, diagnosis, treatment initiation, and the monitoring of treatment efficacy are critical in managing the disease and reducing the number of new infections each year. The introduction of point-of-care HIV rapid tests has transformed the epidemic, particularly in low- and middle-income countries. For the first time, these point-of-care tests allow for the rapid identification of infected individuals outside the laboratory who can undergo counseling and treatment and, in the case of pregnant women, allow the timely initiation of ART to reduce the risk of vertical transmission. Although survival is markedly improved with ART even in the absence of laboratory monitoring, long-term management of people living with HIV on ART, and their partners, is essential to ensure successful viral suppression. The burden of disease in many resource-poor settings with high HIV prevalence has challenged the ability of local laboratories to effectively monitor those on ART. Diagnostics used to initiate and monitor treatment are now moving out of the laboratory and into the field. These new point-of-care tests for viral load and CD4 are poised to further transform the disease and shift the treatment paradigm in low- and middle-income countries.

Care of HIV-positive women aged 50 and over - can we do better?

A sample of 123 HIV-positive women aged 50 years and over showed high rates of late diagnosis with CD4 count <350 (71%), significant co-morbidities (90%), high rates of premature menopause (6.8%) and early menopause (6.8%) and cervical cytological abnormalities (47%). Specific interventions to improve care in this group should include yearly cervical cytology, early counselling with regard to reproductive options, menopause management and screening for sexually transmitted infections (STIs).

Enhancing patient safety with an electronic results checking system in a large HIV outpatient service

OBJECTIVE

To establish whether an automated electronic tracker system for reporting blood results would expedite clinician review of abnormal results in HIV-positive outpatients and to pilot the use of this system in routine clinical practice.

SETTING

An outpatient service in central London providing specialist HIV-related care to 3900 HIV positive patients.

DESIGN

A comparison of the time taken from sampling to identification and clinician review of abnormal blood results for biochemical tests between the original paper-based checking system and an automated electronic system during a 3-week pilot.

RESULTS

Of 513 patients undergoing one or more blood tests, 296 (57%) had one or more biochemical abnormalities identified by electronic checking system. Out of 371 biochemical abnormalities, 307 (82.7%) were identified simultaneously by the paper-based system. Of the 307, 33 (10.7%) were classified as urgent, 130 (42.3%) as non-urgent and 144 (46.9%) as not clinically significant. The median interval between sampling and receipt of results was 1 (interquartile range 1-2) vs 4 days ( interquartile range 3-5), P <0.0001; clinician review 3 (interquartile range 1-4) vs 3 days (interquartile range 3-6), P<0.037; and review of non-urgent abnormalities by the regular clinician 2 (interquartile range 1-4) vs 10 days ( interquartile range 9-12), P=0.136, for electronic and paper-based systems respectively. Seven (11%) of the missing paper-based system results were classified as urgent. The electronic system missed three abnormalities as a result of a software processing error which was subsequently corrected.

CONCLUSIONS

The electronic tracker system allows faster identification of biochemical abnormalities and allowed faster review of these results by clinicians. The pilot study allowed for a software error to be identified and corrected before full implementation. The system has since integrated successfully into routine clinical practice.

Is clinical practice concordant with the changes in guidelines for antiretroviral therapy initiation during primary and chronic HIV-1 infection? The ANRS PRIMO and COPANA cohorts

OBJECTIVE

Guidelines for initiating HIV treatment are regularly revised. We explored how physicians in France have applied these evolving guidelines for ART initiation over the last decade in two different situations: chronic (CHI) and primary HIV-1 infection (PHI), since specific recommendations for PHI are also provided in France.

METHODS

Data came from the ANRS PRIMO (1267 patients enrolled during PHI in 1996-2010) and COPANA (800 subjects enrolled at HIV diagnosis in 2004-2008) cohorts. We defined as guidelines-inconsistent during PHI and CHI, patients meeting criteria for ART initiation and not treated in the following month and during the next 6 months, respectively.

RESULTS

ART initiation during PHI dramatically decreased from 91% of patients in 1996-99 to 22% in 2007 and increased to 60% in 2010, following changes in recommendations. In 2007, however, after the CD4 count threshold was raised to 350 cells/mm(3) in 2006, only 55% of the patients with CD4≤350 were treated and 66% in 2008. During CHI, ART was more frequently initiated in patients who met the criteria at entry (96%) than during follow-up: 83% when recommendation to treat was 200 and 73% when it was 350 cells/mm(3). Independent risk factors for not being treated during CHI despite meeting the criteria were lower viral load, lower educational level, and poorer living conditions.

CONCLUSION

HIV ART initiation guidelines are largely followed by practitioners in France. What can still be improved, however, is time to treat when CD4 cell counts reach the threshold to treat. Risk factors for lack of timely treatment highlight the need to understand better how patients' living conditions and physicians' perceptions influence the decision to initiate treatment.

Liver transplantation for acute liver failure due to efavirenz hepatotoxicity: the importance of routine monitoring

We present the first case report in the UK of acute liver failure caused by efavirenz therapy culminating in liver transplantation. A 26-year-old Zimbabwean woman commenced emtricitabine, tenofovir and efavirenz (Atripla) in December 2011. Her liver function tests at baseline and at 20 days after initiating antiretroviral therapy were normal. At three months of therapy her blood tests haemolysed and were not processed. She had previously missed follow-up appointments and on this occasion failed to return for repeat tests. She was not seen again until after six months of antiretroviral therapy when she presented to her general practitioner with acute liver failure. Her condition deteriorated and she required liver transplantation. She recovered well and re-started antiretroviral therapy to good effect. The case illustrates the value of routine monitoring after initiating antiretroviral therapy and the fundamental importance of engaging patients in long-term management to ensure safe treatment.

Enhanced surveillance of infectious syphilis in New Zealand sexual health clinics

Following a rise in cases of infectious syphilis in New Zealand, national enhanced surveillance at sexual health clinics was initiated. All public sexual health clinics reported monthly on the number of cases seen, and completed a coded questionnaire on each case. Monthly reports to routine surveillance were compared and discrepancies reconciled. During 2011, 72 cases of infectious syphilis were reported. The majority (83%) were among men who have sex with men who were mainly infected in New Zealand and had an ethnic profile similar to all New Zealanders. Most heterosexual infections occurred overseas, among people of non-European non-Maori ethnicity. About half the cases had symptoms on presentation. Overall, 18% of men who have sex with men were HIV positive. Resurgent syphilis in New Zealand disproportionally affects men who have sex with men, amongst whom HIV is prevalent. Men who have sex with men should be aware of the risks and symptoms of syphilis and encouraged to have regular sexual health checks including serology testing. Control of syphilis should be included in the strategy to check HIV spread. Syphilis serology should continue to be part of routine immigration and antenatal screening, and where clinically indicated. Enhanced surveillance was easily initiated for an uncommon condition seen at sexual health clinics, and provided valuable information.

HIV-1 tropism determination using a phenotypic Env recombinant viral assay highlights overestimation of CXCR4-usage by genotypic prediction algorithms for CRF01_AE and CRF02_AG [corrected]

BACKGROUND

Human Immunodeficiency virus type-1 (HIV) entry into target cells involves binding of the viral envelope (Env) to CD4 and a coreceptor, mainly CCR5 or CXCR4. The only currently licensed HIV entry inhibitor, maraviroc, targets CCR5, and the presence of CXCX4-using strains must be excluded prior to treatment. Co-receptor usage can be assessed by phenotypic assays or through genotypic prediction. Here we compared the performance of a phenotypic Env-Recombinant Viral Assay (RVA) to the two most widely used genotypic prediction algorithms, Geno2Pheno[coreceptor] and webPSSM.

METHODS

Co-receptor tropism of samples from 73 subtype B and 219 non-B infections was measured phenotypically using a luciferase-tagged, NL4-3-based, RVA targeting Env. In parallel, tropism was inferred genotypically from the corresponding V3-loop sequences using Geno2Pheno[coreceptor] (5-20% FPR) and webPSSM-R5X4. For discordant samples, phenotypic outcome was retested using co-receptor antagonists or the validated Trofile® Enhanced-Sensitivity-Tropism-Assay.

RESULTS

The lower detection limit of the RVA was 2.5% and 5% for X4 and R5 minority variants respectively. A phenotype/genotype result was obtained for 210 samples. Overall, concordance of phenotypic results with Geno2Pheno[coreceptor] was 85.2% and concordance with webPSSM was 79.5%. For subtype B, concordance with Geno2pheno[coreceptor] was 94.4% and concordance with webPSSM was 79.6%. High concordance of genotypic tools with phenotypic outcome was seen for subtype C (90% for both tools). Main discordances involved CRF01_AE and CRF02_AG for both algorithms (CRF01_AE: 35.9% discordances with Geno2Pheno[coreceptor] and 28.2% with webPSSM; CRF02_AG: 20.7% for both algorithms). Genotypic prediction overestimated CXCR4-usage for both CRFs. For webPSSM, 40% discordance was observed for subtype A.

CONCLUSIONS

Phenotypic assays remain the most accurate for most non-B subtypes and new subtype-specific rules should be developed for non-B subtypes, as research studies more and more draw conclusions from genotypically-inferred tropism, and to avoid unnecessarily precluding patients with limited treatment options from receiving maraviroc or other entry inhibitors.

Viral suppression after 12 months of antiretroviral therapy in low- and middle-income countries: a systematic review

OBJECTIVE

To establish estimates of viral suppression in low- and middle-income countries (LMICs) in patients who received antiretroviral therapy (ART) for human immunodeficiency virus (HIV) infection.

METHODS

Data on viral suppression after 12 months of ART in LMICs were collected from articles published in 2003 to 2011 and from abstracts of conferences held between 2009 and 2011. Pooled proportions for on-treatment and intention-to-treat populations were used as summary estimates. Random-effects models were used for heterogeneous groups of studies (I (2) > 75%).

FINDINGS

Overall, 49 studies covering 48 cohorts and 30 016 individuals met the inclusion criteria. With thresholds for suppression between 300 and 500 copies of viral ribonucleic acid (RNA) per ml of plasma, 84.3% (95% confidence interval, CI: 80.4-87.9) of the pooled on-treatment population and 70.5% (95% CI: 65.2-75.6) of the intention-to-treat population showed suppression. Use of different viral RNA thresholds changed the proportions showing suppression: to 84% and 76% of the on-treatment population with thresholds set above 300 and at or below 200 RNA copies per ml, respectively, and to 78%, 71% and 63% of the intention-to-treat population at thresholds set at 1000, 300 to 500, and 200 or fewer copies per ml, respectively.

CONCLUSION

The pooled estimates of viral suppression recorded after 12 months of ART in LMICs provide benchmarks that other ART programmes can use to set realistic goals and perform predictive modelling. Evidence from this review suggests that the current international target - i.e. viral suppression in > 70% of the intention-to-treat population, with a threshold of 1000 copies per ml - should be revised upwards.

Eosinophilia: clinical significance in HIV-infected individuals

This study was conducted to determine the relationship between eosinophilia and parasitic infection in HIV-infected individuals. HIV-positive patients attending an HIV clinic in Birmingham were recruited and classified as either eosinophilic (>400 eosinophils/mm(3)) or non-eosinophilic. A demographic and parasitic risk history was taken and clinical examination was performed. Urine and stool were examined for parasites, and blood samples taken for parasite serology. A total of 266 patients (96 eosinophilic and 170 non-eosinophilic) were recruited. Of 64 eosinophilic patients who had a stool examination, one (1.6%) was positive for both Strongyloides larvae and schistosomal eggs. Urine microscopy was negative in the 245 patients (88 eosinophilic, 157 non-eosinophilic) from whom a sample was available. Two hundred and sixty-three patients underwent serological investigation (96 eosinophilic and 167 non-eosinophilic): 13 (4.9%) were positive for schistosomiasis and three (1.1%) positive for Strongyloides. A significant association between eosinophilia and positive schistosomal serology was found (P = 0.003): 11 (10.5%) were eosinophilic patients, while only four (2.3%) were non-eosinophilic patients. Eosinophilia was associated with a low nadir CD4 count (P = 0.021) and prior AIDS-defining illness (P = 0.041). In all, 7.8% of patients from a developing country and 5.3% of patients from a developed country with a travel history had positive parasitic serology. Eosinophilia in HIV-infected patients was significantly associated with positive serology for schistosomiasis, low nadir CD4 count and prior AIDS-defining illness. Geographical exposure is also an important determinant of positive parasitic serology.

Effects of age on antiretroviral plasma drug concentration in HIV-infected subjects undergoing routine therapeutic drug monitoring

OBJECTIVES

The pharmacokinetic and pharmacodynamic effects of antiretroviral therapy may differ in older compared with younger subjects with HIV infection. We aimed to assess factors associated with plasma antiretroviral drug exposure, including age, within a large HIV-infected cohort undergoing therapeutic drug monitoring (TDM).

METHODS

Data from the Liverpool TDM Registry were linked with the UK Collaborative HIV Cohort (CHIC) Study. All TDM of protease inhibitors (PIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs) was included and in order to account for different antiretroviral drugs the plasma concentrations were standardized by group measurements according to drug, dosing and timing of TDM. Regression modelling was used to evaluate associations of drug exposure with age and clinical parameters, including hepatic transaminase results and time to antiretroviral treatment modification.

RESULTS

Data from 3589 TDM samples were available from 2447 subjects. The greatest numbers of plasma concentrations were assessed for lopinavir (22.4%), efavirenz (18.5%), atazanavir (17.0%) and saquinavir (11.6%). As age increased, median standardized NNRTI concentrations remained constant, whereas PI concentrations increased (correlation coefficient 0.04, P = 0.033). In a regression analysis stratified by antiretroviral drug class, standardized plasma concentrations were significantly associated with age for PIs (0.05 increase in standard deviation of drug concentration with each 10 year increase in age, P = 0.044), but not for NNRTIs or other clinical parameters, including hepatic transaminase results or time to antiretroviral treatment modification.

CONCLUSIONS

With increasing age, statistically significant rises in plasma PI exposure, but not NNRTI exposure, were observed. The clinical relevance of this observation merits further investigation.

Management of chronic hepatitis B: Canadian Association for the Study of the Liver consensus guidelines

Chronic hepatitis B (CHB) is a dynamic disease that is influenced by host and virological factors. The management of CHB has become more complex with the increasing use of long-term oral nucleos⁄tide analogue antiviral therapies and the availability of novel diagnostic assays. Furthermore, there is often a lack of robust data to guide optimal management such as the selection of therapy, duration of treatment, potential antiviral side effects and the treatment of special populations. In November 2011, the Canadian Liver Foundation and the Canadian Association for the Study of the Liver convened a consensus conference to review the literature and analyze published data, including other international expert guidelines on CHB management. The proceedings of the consensus conference are summarized and provide updated clinical practice guidelines to assist Canadian health care providers in the prevention, diagnosis, assessment and treatment of CHB.

Prevalence of HIV-1 drug resistance in treated patients with viral load >50 copies/mL in 2009: a French nationwide study

BACKGROUND

Surveillance of HIV-1 drug resistance in treated patients with plasma viral load (VL) >50 copies/mL.

METHODS

The protease and reverse transcriptase (RT) genes were systematically sequenced in samples from 756 patients with VL >50 copies/mL in 2009. The genotyping results were interpreted for each antiretroviral drug (ARV) by using the ANRS algorithm v21. Weighted analyses were used to derive representative estimates of percentages of patients. Prevalence rates were compared with those obtained in 2004 among patients with VL >1000 copies/mL.

RESULTS

Sequences were obtained for 506 patients. Sequencing was successful in 45%, 80% and 96% of samples with VL of 51-500, 501-1000 and >1000 copies/mL, respectively. Resistance or possible resistance to at least one ARV was observed in 59% of samples. Overall, 0.9% of samples contained viruses resistant to all drugs belonging to at least three drug classes. All resistance prevalence rates were significantly lower in 2009 than in 2004.

CONCLUSION

In France, where 86% of patients were receiving combination antiretroviral therapy in 2009, only 15.0% of patients had a VL >50 copies/mL, suggesting that only 8.9% of treated patients could potentially transmit resistant viruses. Only 0.08% of patients harboured viruses fully resistant to at least three antiretroviral drug classes. Further studies are needed to determine whether resistance continues to decline over time.

Pharmacokinetic profile and safety of 150 mg of maraviroc dosed with 800/100 mg of darunavir/ritonavir all once daily, with and without nucleoside analogues, in HIV-infected subjects

BACKGROUND

Once-daily nucleoside-sparing combination antiretroviral therapy regimens are attractive options for the treatment of HIV infection. However, the pharmacokinetic profiles of such regimens are often not established.

METHODS

HIV-infected subjects receiving 245/200 mg of tenofovir/emtricitabine plus 800/100 mg of darunavir/ritonavir once daily with plasma HIV RNA <50 copies/mL were eligible. On day 1 (period 1), 150 mg of maraviroc daily was added and on day 11 (period 2), tenofovir/emtricitabine discontinued. At steady-state (days 10 and 20), intensive pharmacokinetic sampling was undertaken. We assessed (i) the number of subjects with trough (C(trough)) and average (C(avg)) maraviroc concentrations <25 and <75 ng/mL, respectively; (ii) geometric mean (GM) ratios for pharmacokinetic parameters for period 2 versus period 1; and (iii) factors associated with total maraviroc exposure.

RESULTS

Eleven subjects completed the study procedures (mean age 49 years; range 35-59 years). In three subjects, maraviroc C(trough) and C(avg) were <25 and <75 ng/mL, respectively (C(avg), 68 ng/mL and C(trough), 14 and 21 ng/mL). Although not statistically significant, a trend was observed towards lower maraviroc, darunavir and ritonavir concentrations in period 2 versus period 1; total maraviroc exposure was 3579 ng· h/mL (95% CI: 2983-4294) and 2996 ng· h/mL (95% CI: 2374-3782) in periods 1 and 2, respectively, and the GM ratio was 0.84 (95% CI: 0.67-1.05). Only total ritonavir exposure was significantly associated with total maraviroc exposure (P=0.049; 95% CI: 0.01-0.91). No clinical safety concerns were observed.

CONCLUSIONS

Within this novel nucleoside-sparing regimen, maraviroc exposure is dependent on ritonavir exposure, which was slightly reduced in the absence of tenofovir/emtricitabine.

The safety of flucloxacillin in HIV-infected patients with positive HLA-B*5701 genotype

Positive HLA-B*5701 genotype has recently been identified as the main genetic risk factor for flucloxacillin drug-induced liver injury (DILI). Testing for HLA-B*5701 is routine in many HIV clinics to identify those at risk of hypersensitivity reaction (HSR) to abacavir. Considering the high prevalence of soft-tissue infections in HIV patients, we conducted a retrospective study to investigate whether flucloxacillin use was associated with adverse events in HIV patients known to be HLA-B*5701 positive.

The prevalence of cryptococcal antigenemia in newly diagnosed HIV patients in a Southwest London cohort

OBJECTIVES

To determine the prevalence of cryptococcal antigenemia in a UK HIV cohort and compare baseline characteristics of patients with and without cryptococcal antigenemia.

METHODS

Stored sera were retrospectively tested for cryptococcal antigen (CRAG) among newly diagnosed HIV-infected persons with CD4 < 100 cells/μL, who presented to Croydon University and St George's Hospitals, London, between January 2004 and October 2010. We assessed risk factors for cryptococcal antigenemia and patient outcomes by extracting demographic and clinical information from medical records.

RESULTS

157 patients were identified with a median age of 47 and CD4 count of 26 cells/μL. 102 (65%) were of Black race and 91 (58%) of African origin. Eight patients (5%) had positive serum CRAG. 7/8 had cryptococcal meningitis (CM) as first presentation of HIV, and 1 had sub-clinical infection. 7/8 (88%) CRAG positives were of African origin compared to 84/149 (54%) of CRAG negatives (p = 0.14). Other baseline characteristics did not differ significantly.

CONCLUSION

We found a 5% prevalence of cryptococcal antigenemia in newly diagnosed HIV patients with CD4 < 100 cells/μL in southwest London, the first such data for a UK HIV cohort. Cryptococcal antigenemia occurred almost exclusively in African-born individuals. We recommend a UK CRAG screening strategy targeting newly diagnosed African HIV-infected patients with CD4 < 100 cells/μL.

Comprehensive evaluation of two HLA-B17 monoclonal antibodies for flow cytometry-based HLA-B57/B58 screening prior to abacavir prescription

Hypersensitivity reactions to the drug abacavir, used to treat HIV/AIDS patients, is associated with possession of HLA-B*57:01. We have carefully assessed two commercially available HLA-B57/B58 murine monoclonal antibodies [0196HA and BIH0243 (One Lambda Inc.)] in a simple flow cytometry-based assay. The evaluation involved tests on 228 reference and random samples covering 91% of all WHO recognized HLA-A, B and C specificities. These involved donors with six different HLA-B*57 alleles and included 19 examples of B*57:01. Both antibodies unambiguously detected B57, but there were small difference in their reactivity against B57-positive non-B*57:01 samples. Importantly, there was no reactivity against B57/B58-negative samples. The possible amino acid motifs involved in the reactivity of these antibodies with B57/B58 were delineated. Thus, HLA-B57/B58, normally present in <10% of patients, can be easily recognized using these two antibodies and further tested by a DNA-based typing method to identify B*57:01.

Total protein, albumin and low-molecular-weight protein excretion in HIV-positive patients

BACKGROUND

Chronic kidney disease is common in HIV positive patients and renal tubular dysfunction has been reported in those receiving combination antiretroviral therapy (cART). Tenofovir (TFV) in particular has been linked to severe renal tubular disease as well as proximal tubular dysfunction. Markedly elevated urinary concentrations of retinal-binding protein (RBP) have been reported in patients with severe renal tubular disease, and low-molecular-weight proteins (LMWP) such as RBP may be useful in clinical practice to assess renal tubular function in patients receiving TFV. We analysed 3 LMWP as well as protein and albumin in the urine of a sample of HIV positive patients.

METHODS

In a cross-sectional fashion, total protein, albumin, RBP, cystatin C, and neutrophil gelatinase-associated lipocalin (NGAL) were quantified in random urine samples of 317 HIV positive outpatients and expressed as the ratio-to-creatinine (RBPCR, CCR and NGALCR). Exposure to cART was categorised as none, cART without TFV, and cART containing TFV and a non-nucleoside reverse-transcriptase-inhibitor (TFV/NNRTI) or TFV and a protease-inhibitor (TFV/PI).

RESULTS

Proteinuria was present in 10.4 % and microalbuminuria in 16.7 % of patients. Albumin accounted for approximately 10 % of total urinary protein. RBPCR was within the reference range in 95 % of patients while NGALCR was elevated in 67 % of patients. No overall differences in urine protein, albumin, and LMWP levels were observed among patients stratified by cART exposure, although a greater proportion of patients exposed to TFV/PI had RBPCR >38.8 μg/mmol (343 μg/g) (p = 0.003). In multivariate analyses, black ethnicity (OR 0.43, 95 % CI 0.24, 0.77) and eGFR <75 mL/min/1.73 m2 (OR 3.54, 95 % CI 1.61, 7.80) were independently associated with upper quartile (UQ) RBPCR. RBPCR correlated well to CCR (r2 = 0.71), but not to NGALCR, PCR or ACR.

CONCLUSIONS

In HIV positive patients, proteinuria was predominantly of tubular origin and microalbuminuria was common. RBPCR in patients without overt renal tubular disease was generally within the reference range, including those receiving TFV. RBP therefore appears a promising biomarker for monitoring renal tubular function in patients receiving TFV and for distinguishing patients with normal tubular function or mild tubular dysfunction from those with severe renal tubular disease or Fanconi syndrome.