Efficacy of short-term monotherapy with maraviroc, a new CCR5 antagonist, in patients infected with HIV-1

We assessed the efficacy and safety of 10-d monotherapy with the orally administered CCR5 antagonist maraviroc in 63 HIV-1-positive individuals prescreened for the absence of CXCR4-using virus. Maximum reduction in viral load occurred at a median of 10-15 d, with a mean reduction of >or=1.6 log(10) copies/ml at all twice daily doses >or=100 mg. These results provide proof of concept that CCR5 antagonism is a viable antiretroviral therapeutic approach.

Emergence of CXCR4-using human immunodeficiency virus type 1 (HIV-1) variants in a minority of HIV-1-infected patients following treatment with the CCR5 antagonist maraviroc is from a pretreatment CXCR4-using virus reservoir

Antagonists of the human immunodeficiency virus type 1 (HIV-1) coreceptor, CCR5, are being developed as the first anti-HIV agents acting on a host cell target. We monitored the coreceptor tropism of circulating virus, screened at baseline for coreceptor tropism, in 64 HIV-1-infected patients who received maraviroc (MVC, UK-427,857) as monotherapy for 10 days. Sixty-two patients harbored CCR5-tropic virus at baseline and had a posttreatment phenotype result. Circulating virus remained CCR5 tropic in 60/62 patients, 51 of whom experienced an HIV RNA reduction from baseline of >1 log(10) copies/ml, indicating that CXCR4-using variants were not rapidly selected despite CCR5-specific drug pressure. In two patients, viral load declined during treatment and CXCR4-using virus was detected at day 11. No pretreatment factor predicted the emergence of CXCR4-tropic virus during maraviroc therapy in these two patients. Phylogenetic analysis of envelope (Env) clones from pre- and posttreatment time points indicated that the CXCR4-using variants probably emerged by outgrowth of a pretreatment CXCR4-using reservoir, rather than via coreceptor switch of a CCR5-tropic clone under selection pressure from maraviroc. Phylogenetic analysis was also performed on Env clones from a third patient harboring CXCR4-using virus prior to treatment. This patient was enrolled due to a sample labeling error. Although this patient experienced no overall reduction in viral load in response to treatment, the CCR5-tropic components of the circulating virus did appear to be suppressed while receiving maraviroc as monotherapy. Importantly, in all three patients, circulating virus reverted to predominantly CCR5 tropic following cessation of maraviroc.

Intravenous cidofovir for peripheral cytomegalovirus retinitis in patients with AIDS. A randomized, controlled trial

BACKGROUND

Cytomegalovirus (CMV) retinitis is the most common intraocular infection in patients with the acquired immunodeficiency syndrome (AIDS). If left untreated, it may lead to progressive destruction of retinal tissue and blindness. Cidofovir is a nucleotide analogue of cytosine that has potent, prolonged in vitro and in vivo activity against herpesviruses, including many CMV isolates that are resistant to ganciclovir and foscarnet.

OBJECTIVE

To determine whether intravenous cidofovir delays progression of previously untreated CMV retinitis.

DESIGN

Randomized, controlled trial comparing immediate with deferred cidofovir treatment. Patients in the deferred treatment group were eligible to receive cidofovir after progression of CMV retinitis was documented by retinal photography.

SETTING

Eight academic medical centers and an independent center that read retinal photographs.

PATIENTS

48 patients with AIDS and previously untreated peripheral CMV retinitis who were randomly assigned to immediate (n = 25) or deferred treatment (n = 23).

INTERVENTION

Intravenous cidofovir, 5 mg/kg of body weight, once weekly for 2 weeks and then once every other week. To minimize nephrotoxicity, oral probenecid and intravenous hydration with normal saline were administered with each cidofovir infusion.

MEASUREMENTS

Progression of CMV retinitis was assessed by bilateral, full-field retinal photographs that were read by an ophthalmologist who was masked to treatment assignment. Incidence of side effects, changes in visual acuity, effect on CMV shedding in urine and blood, and mortality were also assessed.

RESULTS

The median time to progression of CMV retinitis was 22 days (95% CI, 10 to 27 days) in the deferred treatment group and 120 days (CI, 40 to 134 days) in the immediate treatment group (P < 0.001). Neutropenia (15%) and proteinuria (12%), both asymptomatic, were the most common serious adverse events considered to be possibly related to cidofovir. Cidofovir treatment was discontinued in 10 of 41 patients (24%) because of protocol-defined treatment-limiting nephrotoxicity. Transient reactions to probenecid, including mild to moderate constitutional symptoms or nausea, occurred in 23 of 41 patients (56%) and were dose limiting in 3 (7%).

CONCLUSIONS

Cidofovir was efficacious in delaying progression of previously untreated CMV retinitis. Treatment was associated with manageable side effects; strict adherence to monitoring of renal function before cidofovir was administered and concomitant administration of probenecid and saline hydration appeared to minimize drug-related nephrotoxicity.

Late presenters in the era of highly active antiretroviral therapy: uptake of and responses to antiretroviral therapy

OBJECTIVES

To investigate the characteristics and clinical, immunological and virological outcomes for individuals presenting for care with low CD4 cell counts.

METHODS

Individuals aged > 16 years presenting for care for the first time were identified between 1 January 1996 and 31 December 2002. Late presenters were those with CD4 cell count < 50 x 10(6) cells/l. Follow-up was until last contact, death or 31 December 2002.

RESULTS

Late presenters formed 15.3% (110) of the group; they were more likely to be female (35% versus 24%), heterosexual (53% versus 38%), and of Black-African ethnicity (39% versus 27%) than other individuals. Over a median follow-up of 2.5 years, 13% of late presenters died. Ninety-nine patients started antiretroviral treatment; Of the 11 patients who did not start antiretroviral treatment, eight died within 3 months of presentation. Among those starting treatment, 87 (87.9%) achieved a viral load < 400 copies/ml and median CD4 cell counts increased from 43 x 10(6) cells/l at 0-2 months after presentation to 204 x 10(6) cells/l at 1 year. Over the first year, 71 patients attended at least one outpatient visit (median, 4.5; range, 0-39), 21 attended at least one day case visit (median, 0; range, 0-15) and 49 were admitted as an inpatient (median, 0; range, 0-4).

CONCLUSIONS

Those presenting for care with very low CD4 cell counts may make large demands on clinical resources, particularly over the first few months. While some patients do have a poor outcome on highly active antiretroviral therapy, many will benefit from this therapy and will experience good immunological and virological responses.

Reasons for modification and discontinuation of antiretrovirals: results from a single treatment centre

OBJECTIVE

To describe the reasons for, and factors associated with, modification and discontinuation of highly active antiretroviral therapy (HAART) regimens at a single clinic.

SUBJECTS

A total of 556 patients who started HAART at the Royal Free Hospital were included in analyses. Modification was defined as stopping or switching any antiretrovirals in the regimen, whereas discontinuation was defined as the simultaneous stopping of all antiretrovirals included in the initial regimen. Reasons were classified as immunological/virological failure (IVF) and toxicities and patient choice/poor compliance (TPC).

RESULTS

The median CD4 count at starting HAART was 171 x 10(6) cells/l and viral load 5.07 log copies/ml. During a median follow-up of 14.2 months, 247 patients (44.4%) modified their HAART regimen, 72 due to IVF (29.1%) and 159 due to TPC (64.4%) and a total of 148 patients (26.6%) discontinued HAART. Older patients were less likely to modify HAART [relative hazard (RH), 0.73 per 10 years; P = 0.0008], as were previously treatment-naive patients (RH, 0.65; P = 0.0050), those in a clinical trial (RH, 0.64; P = 0.027) and those who started nelfinavir (RH, 0.57; P = 0.035). Patients who started with four or more drugs (RH, 2.21, P < 0.0001), who included ritonavir in the initial regimen (RH, 1.41; P = 0.035) or who had higher viral loads during follow-up (RH per log increase, 1.51; P < 0.0001) were more likely to modify HAART.

CONCLUSIONS

There was a high rate of modification and discontinuation of HAART regimens in the first 12 months, particularly due to toxicities, patient choice or poor compliance.

Randomized trial to evaluate indinavir/ritonavir versus saquinavir/ritonavir in human immunodeficiency virus type 1-infected patients: the MaxCmin1 Trial

This trial assessed the rate of virological failure at 48 weeks in adult human immunodeficiency virus (HIV) type 1-infected patients assigned indinavir/ritonavir (Idv/Rtv; 800/100 mg 2 times daily) or saquinavir/ritonavir (Sqv/Rtv; 1000/100 mg 2 times daily) in an open-label, randomized (1:1), multicenter, phase 4 design. Three hundred six patients began the assigned treatment. At 48 weeks, virological failure was seen in 43 (27%) of 158 and 37 (25%) of 148 patients in the Idv/Rtv and Sqv/Rtv arms, respectively. The time to virological failure did not differ between study arms (P=.76). When switching from randomized treatment was counted as failure, this was seen in 78 of 158 patients in the Idv/Rtv arm, versus 51 of 148 patients in the Sqv/Rtv arm (P=.009). A switch from the randomized treatment occurred in 64 (41%) of 158 patients in the Idv/Rtv arm, versus 40 (27%) of 148 patients in the Sqv/Rtv arm (P=.013). Sixty-four percent of the switches occurred because of adverse events. A greater number of treatment-limiting adverse events were observed in the Idv/Rtv arm, relative to the Sqv/Rtv arm. In conclusion, Rtv-boosed Sqv and Idv were found to have comparable antiretroviral effects in the doses studied.

A randomized, double-blind trial of valaciclovir prophylaxis for cytomegalovirus disease in patients with advanced human immunodeficiency virus infection. AIDS Clinical Trials Group Protocol 204/Glaxo Wellcome 123-014 International CMV Prophylaxis Study Group

Cytomegalovirus (CMV) disease is a common complication of advanced human immunodeficiency virus (HIV) infection. Administration of oral valaciclovir, a valine ester of acyclovir, achieves sufficient plasma acyclovir levels to inhibit many clinical isolates. Acyclovir has been associated with enhanced survival in AIDS but not with CMV disease prevention. CMV-seropositive patients (1227) with CD4 cell counts <100/mm3 were enrolled in a randomized, double-blind trial. Valaciclovir, 8 g/day, was compared with acyclovir, 3.2 or 0.8 g/day, for CMV prevention; all three arms were compared for survival. The confirmed CMV disease rate was 11.7% among valaciclovir recipients and 17.5% in the pooled acyclovir arms, a 33% reduction in risk. Time to confirmed CMV disease was significantly longer for the valaciclovir group (P = .03). A trend toward earlier mortality for valaciclovir recipients was seen (P = .06). Toxicity and earlier medication discontinuation were more common in this group. Valaciclovir significantly reduces the risk of CMV disease. Further exploration of a better-tolerated dose is warranted.

Sexual dysfunction associated with protease inhibitor containing highly active antiretroviral treatment

BACKGROUND

A high proportion of individuals receiving highly active antiretroviral treatment (HAART) complain of sexual dysfunction (SD), encompassing a lack of desire or erectile dysfunction.

OBJECTIVE

To determine whether SD was associated with particular components of the HAART regimens and to identify risk factors for the development of SD in patients on HAART.

METHODS

A survey among patients with HIV infection using an anonymous questionnaire was conducted in 10 European countries between December 1998 and December 1999. A total of 904 individuals currently receiving antiretroviral agents were included in the analyses.

RESULTS

A decrease in sexual interest was significantly more frequently reported by subjects (men and women) using HAART containing protease inhibitors (PI) (308/766, 40%), compared with PI-naive patients (22/138, 16%; OR 3.55; 95% CI 2.15--5.89). In addition, a significantly larger number of PI-experienced men reported a decrease in sexual potency (216/628, 34%) compared with PI-naive men (12/99, 12%; OR 2.56; 95% CI 1.33--5.03). In multivariate analyses the following factors were associated with a decrease in sexual interest: a current PI-containing regimen, a history of a PI regimen, symptomatic HIV infection, age and homosexual contact as HIV transmission mode. Factors associated with a decrease in sexual potency were: current use of a PI-containing regimen, symptomatic HIV disease, age and the use of tranquillisers.

CONCLUSION

SD appears to be a common side-effect of HAART regimens containing a PI. The potential association between SD and other side-effects of HAART, such as lipodystrophy syndrome and neuropathy, should be investigated further.

Randomized, controlled study of the safety and efficacy of intravenous cidofovir for the treatment of relapsing cytomegalovirus retinitis in patients with AIDS

To assess the effect of intravenous cidofovir on delaying progression of previously treated, relapsing cytomegalovirus (CMV) retinitis, we conducted a randomized, controlled comparison of two maintenance dose levels of cidofovir. One hundred and fifty patients with AIDS and CMV retinitis that had progressed or was persistently active despite treatment with ganciclovir, foscarnet, or both were randomized to receive induction cidofovir, 5 mg/kg once weekly for 2 weeks, then maintenance therapy with either 5 mg/kg or 3 mg/kg once every other week. Concomitant probenecid and intravenous hydration were administered with each cidofovir dose. Retinitis progression was assessed in the first 100 patients by bilateral, full-field retinal photographs read at a central reading center by an ophthalmologist masked to treatment assignment. Incidence of side effects, changes in visual acuity, and mortality were also assessed. Median time to retinitis progression as assessed by retinal photography was not reached (95% confidence interval [CI], 115 days-upper limit not reached) in the 5-mg/kg group, and was 49 days (95% CI, 35-52 days) in the 3-mg/kg group (p = .0006). Dose-dependent asymptomatic proteinuria (39%) and serum creatinine elevation (24%) were the most common adverse events thought to be related to cidofovir. Reversible probenecid reactions including constitutional symptoms and nausea occurred in 65 of 150 (43%) patients. Cidofovir therapy is effective in delaying progression of CMV retinitis that had previously progressed using other anti-CMV therapies.

British HIV Association guidelines for the treatment of HIV-1-positive adults with antiretroviral therapy 2012

The overall purpose of these guidelines is to provide guidance on best clinical practice in the treatment and management of adults with HIV infection with antiretroviral therapy (ART). The scope includes: (i) guidance on the initiation of ART in those previously naïve to therapy; (ii)support of patients on treatment; (iii) management of patients experiencing virological failure; and (iv) recommendations in specific patient populations where other factors need to be taken into consideration. The guidelines are aimed at clinical professionals directly involved with and responsible for the care of adults with HIV infection and at community advocates responsible for promoting the best interests and care of HIV-positive adults. They should be read in conjunction with other published BHIVA guidelines.

Acetyl-l-carnitine: a pathogenesis based treatment for HIV-associated antiretroviral toxic neuropathy

BACKGROUND

Nucleoside analogue reverse transcriptase inhibitors (NRTI) disrupt neuronal mitochondrial DNA synthesis, impairing energy metabolism and resulting in a distal symmetrical polyneuropathy (DSP), an antiretroviral toxic neuropathy (ATN) that causes significant morbidity in HIV disease. Serum acetyl-l-carnitine (ALCAR) levels are decreased in neuropathy associated with NRTI therapy. ALCAR enhances neurotrophic support of sensory neurons and promotes energy metabolism, potentially causing nerve regeneration and symptom relief.

OBJECTIVE

To assess the efficacy of oral ALCAR (1500 mg twice daily) for up to 33 months in an open cohort of 21 HIV-positive patients with established ATN.

METHODS

Skin biopsies were excised from the leg before ALCAR treatment, at 6-12 month intervals thereafter and from HIV-negative non-neuropathic controls. Fibre types in epidermal, dermal and sweat gland innervation were quantified immunohistochemically.

RESULTS

After 6 month's treatment, mean immunostaining area for small sensory fibres increased (epidermis 100%, P = 0.006; dermis 133%, P < 0.05) by more than that for all fibre types (epidermis 16%, P = 0.04; dermis 49%, P < 0.05; sweat glands 60%, P < 0.001) or for sympathetic fibres (sweat glands 41%, P < 0.0003). Compared with controls, epidermal, dermal and sweat gland innervation reached 92%, 80% and 69%, respectively, after 6 month's treatment. Innervation improvements continued (epidermis and dermis) or stabilized (sweat glands) after 24 month's treatment. Neuropathic grade improved in 76% of patients and remained unchanged in 19%. HIV RNA load, CD4 and CD8 cell counts did not alter significantly throughout the study.

CONCLUSIONS

ALCAR treatment improves symptoms, causes peripheral nerve regeneration and is proposed as a pathogenesis-based treatment for DSP.

Immunological, virological and clinical response to highly active antiretroviral therapy treatment regimens in a complete clinic population. Royal Free Centre for HIV Medicine

BACKGROUND

Highly active antiretroviral therapy (HAART) is now widely used in clinical practice and gives rise to a range of immunological, virological and clinical responses.

OBJECTIVES

To describe the immunological, virological and clinical response to HAART and to examine the frequency of modification of the HAART regimen among patients from a single treatment centre.

METHODS

Kaplan-Meier estimation and incidence rates were used to describe responses to HAART (a protease inhibitor or non-nucleoside drug in addition to at least two nucleoside analogues) among 421 patients from the Royal Free Hospital in London.

RESULTS

The median CD4 cell count at starting HAART was 186 x 10(6) cells/l [interquartile range (IQR) 76-310] and viral load was 5.13 log10 copies/ml (IQR 4.66-5.56). At 6 months after starting HAART, 51.1% of patients were estimated to have experienced a 100 x 10(6) cells/l increase in CD4 cell count; the median time for viral load to fall below 400 copies/ml was 3.7 months (95% confidence interval 3.2-4.4). At 6 months after the first viral load was < 400 copies/ml, 16.4% of patients were estimated to have failed on the basis of a single viral load > 400 copies/ml and 12.4% were estimated to have failed if the more stringent definition of two viral loads above the limit of detection was used. Compared with the pre-HAART era, the incidence of death among patients on HAART was one sixth of that level; new AIDS-defining illnesses was one seventh; and hospital admissions was one fifth. In total, 141 patients (33.5%) stopped at least one of the antiretroviral agents included as part of their HAART regimen; the occurrence of side effects was the most common reason (n = 63; 44.7%).

CONCLUSION

A good response occurred to an initial HAART regimen. There was a high rate of virological relapse, which varied considerably according to the definition of failure used. Even so, the rates of clinical progression and hospital admissions observed to date were low. Further follow-up of these patients is required to determine their long-term immunological, virological and clinical outcome.

Changes Over Time in Risk of Initial Virological Failure of Combination Antiretroviral Therapy

BACKGROUND

Triple-combination antiretroviral therapy (CART) for human immunodeficiency virus infection has been in use for almost a decade, but the extent to which treatment success has changed is uncertain. We examined risk of initial virological failure of CART according to the year of starting therapy.

METHODS

We included subjects from 5 complete clinic cohorts in Europe and Canada who started CART without previous antiretroviral therapy from 1996 to 2002 with 1 or more pre-CART viral load (VL) measurement and CD4 count. Based on the first VL measurement from 6 to 12 months after CART initiation, virological failure was defined as a VL of more than 500 copies/mL. We used the following 3 inclusion strategies: (1) including all subjects, with missing VL measurement counted as virological failure (n = 3825; strategy A); (2) including all subjects with VL measurement (n = 3120; strategy B); and (3) including all subjects receiving antiretroviral therapy at VL measurement (n = 2890; strategy C).

RESULTS

From 1996 to 2002, risk of virological failure fell from 38.9% to 24.8% for strategy A, 28.4% to 12.0% for strategy B, and 22.8% to 8.2% for strategy C. Estimated relative reductions in risk (95% confidence interval) over the 7-year period, adjusted for cohort, demographic factors, pre-CART VL and CD4 count, and previous AIDS, were 48% (39%-56%), 64% (53%-73%), and 79% (69%-85%) for strategies A, B, and C, respectively. Reductions in risk were greatest from 1996 to 1999, with weaker trends subsequently. Trends remained but were attenuated after further adjustment for the starting regimen.

CONCLUSIONS

Over a 7-year period of CART use in clinical practice, risk of initial virological failure of treatment has halved at least. These data suggest the trend is due to improvements in CART regimens and greater effectiveness of their use.

Overview of boosted protease inhibitors in treatment-experienced HIV-infected patients

Antiretroviral drug combinations that include two nucleoside reverse transcriptase inhibitors and a protease inhibitor (PI) can suppress HIV replication to undetectable levels, improving the prognosis of HIV-infected individuals. The aim of therapy is complete virological suppression, with a current goal of <50 copies/mL HIV-1 RNA, in order to minimize the occurrence of drug resistance. Improved understanding of the pharmacology of PIs, primarily the importance of adequate drug exposure, has led to the widespread administration of PIs combined with a low 'boosting' dose of ritonavir. The combination of PIs with ritonavir can improve treatment responses in both treatment-naive and -experienced patients. Boosted PIs are an important therapeutic option for HIV and extensive data exist supporting their use. Use of individual agents should be guided by a resistance test at all stages of treatment from naive through to highly treatment-experienced patients. Currently, seven boosted PIs have both US and European licensing approval: indinavir, saquinavir, lopinavir, fosamprenavir, atazanavir, tipranavir and darunavir (formerly TMC114). The preferred first-line option in the USA is lopinavir. Many of the older PIs are less effective and/or have less favourable tolerability profiles. Emergent PI resistance is a major challenge in treatment, and it can be accelerated by partial suppression of viral load through inappropriate therapy combinations. Using the newer boosted PIs, which have more robust resistance profiles, with an optimized background regimen may increase the likelihood of complete viral suppression. This review discusses the relative strengths and weaknesses of boosted PIs in current practice.

A double-blind, parallel-group, placebo-controlled, multicentre study of acetyl l-carnitine in the symptomatic treatment of antiretroviral toxic neuropathy in patients with HIV-1 infection

BACKGROUND

Nucleoside reverse transcriptase inhibitors (NRTIs) disrupt neuronal mitochondrial DNA synthesis, resulting in antiretroviral toxic neuropathy (ATN). Acetyl-L-carnitine (ALCAR) enhances neurotrophic support of sensory neurones, potentially providing symptom relief and nerve regeneration.

OBJECTIVE

The objective of the study was to assess the safety and efficacy compared to placebo of intramuscular ALCAR in HIV-positive patients with symptomatic distal symmetrical polyneuropathy.

METHODS

Ninety patients were enrolled and randomized to receive ALCAR [500 mg twice a day (bid); n=43] or placebo (n=47) intramuscularly twice daily for 14 days followed by 42 days of oral ALCAR 1000 mg bid. Assessment of pain was obtained using the Visual Analogue Scale (VAS), Total Symptom Score (TSS), Clinical Global Impression of Change, McGill Pain Questionnaire (MPQ), and the need for rescue analgesics.

RESULTS

There was no statistically significant difference in changes in VAS over 14 days between groups for the intent-to-treat (ITT) population, but for the efficacy-evaluable (EE) population ALCAR treatment produced a significantly greater reduction in pain compared with placebo (P=0.022). The proportion of patients with an improvement in TSS over 14 days was greater in the ALCAR group compared with the placebo group, but the differences were not statistically significant. During the open-label phase, patients experienced an improvement in pain, as measured by the VAS, TSS and McGill Pain Questionnaire.

CONCLUSION

ALCAR, administered twice a day intramuscularly to HIV-1-infected patients with symptomatic ATN, significantly reduced weekly mean pain ratings on the VAS compared with placebo. Treatment with oral ALCAR improved symptoms for the patient group as a whole. Intramuscular and oral ALCAR was generally safe and well tolerated.

Chronic erosive herpes simplex virus infection of the penis, a possible immune reconstitution disease

OBJECTIVE

To report a novel clinical presentation: a chronic erosive herpes simplex virus (HSV) infection of the penis which developed in AIDS patients following the commencement of highly active antiretroviral therapy (HAART). The lesions were unresponsive to antiviral treatments which had previously been effective, and this could not be accounted for in terms of increased antiviral resistance.

DESIGN

Detailed case-note review and investigation of three cases which presented at two large HIV units in London.

METHODS

Review of all histology with immunohistochemistry for HSV, HSV drug susceptibility assays, tissue typing and measurement of in vitro lymphocyte functional activity against HSV.

RESULTS

The histology of the lesions was the same in each case, with the presence of HSV on immunohistochemistry and an unusual prominence of plasma cell and eosinophils in the inflammatory infiltrate. HSV-specific lymphoproliferative responses were normal in two cases, but subnormal in a third case. All individuals shared the HLA class I molecules B72 and Cw0202 and the class II allele DRB4.

CONCLUSION

We believe this to be a previously unreported adverse consequence of HAART, the result of partial immune restoration, reminiscent of the the recently described syndrome of immune recovery vitritis.

Deaths in the era of HAART: contribution of late presentation, treatment exposure, resistance and abnormal laboratory markers

OBJECTIVES

To describe the characteristics of deaths that occur among HIV-positive individuals in the HAART era.

DESIGN

Observational database.

METHODS

Deaths were reviewed that occurred among HIV-positive individuals seen at the Royal Free Hospital, London between January 1998 and December 2003.

RESULTS

Over the study period, there were 121 deaths; death rates declined from approximately 2.0/100 person-years of follow-up in 1998-2000 to approximately 1.0/100 person-years of follow-up in 2001-2003. Approximately one half of deaths (45.5%) were from AIDS-related causes and 74 deaths (61.2%) occurred in individuals who had received HAART: patients had been exposed to a median of seven (range 2-14) antiretroviral drugs and two-fifths had started treatment in the pre-HAART era. Another 15 patients had received only non-HAART treatment regimens prior to death. The median pre-death CD4 cell counts were 68 and 167 cells/microl among those who had and had not received HAART; 23 (31.1%) and 4 (8.5%) had HIV RNA < 400 copies/ml, respectively. Of the patients exposed to HAART for at least 6 months and who experienced viral rebound, information was available on resistance for 26 (21.5% of the total deaths) and 19 of those tested had at least one resistance mutation (median 5, range, 1-16).

CONCLUSIONS

While mortality rates among HIV-infected individuals at our centre have fallen since 1988, the deaths that do now occur are more diverse and are the result of a number of factors, including late presentation, delayed uptake of HAART and the previous use of treatment combinations that are now viewed as suboptimal.

Effects of passive immunization in patients with the acquired immunodeficiency syndrome-related complex and acquired immunodeficiency syndrome

Infection with the human immunodeficiency virus type 1 (HIV-1) is usually followed by a vigorous immune response that temporarily protects against disease progression. After a variable asymptomatic period, acquired immunodeficiency syndrome (AIDS)-related complex (ARC) and AIDS develop in most infected individuals. We have demonstrated that healthy HIV-1-infected individuals have neutralizing antibodies and a high titer of antiviral antibodies. In contrast, AIDS patients have undetectable levels of neutralizing antibodies, low titers of antiviral antibodies, and, frequently, HIV p24 antigenemia. These observations prompted us to attempt passive immunization in ARC and AIDS patients. Ten consistently viral-antigen-positive patients (mean, greater than 6 months) were treated, resulting in sustained clearance of p24 antigen. Patients either maintained or increased their antiviral antibody titers. The raised titers result from increased antibody synthesis by the recipients. Circulating CD4+ cell counts were unchanged after 2 months. By the third month none of these patients remained in hospital. As this treatment was of minimal toxicity, it merits wider evaluation in ARC and AIDS patients.

Systemic acetyl-L-carnitine eliminates sensory neuronal loss after peripheral axotomy: a new clinical approach in the management of peripheral nerve trauma

Several hundred thousand peripheral nerve injuries occur each year in Europe alone. Largely due to the death of around 40% of primary sensory neurons, sensory outcome remains disappointingly poor despite considerable advances in surgical technique; yet no clinical therapies currently exist to prevent this neuronal death. Acetyl- L-carnitine (ALCAR) is a physiological peptide with roles in mitochondrial bioenergetic function, which may also increase binding of nerve growth factor by sensory neurons. Following unilateral sciatic nerve transection, adult rats received either one of two doses of ALCAR or sham, or no treatment. Either 2 weeks or 2 months later, L4 and L5 dorsal root ganglia were harvested bilaterally, in accordance with the Animal (Scientific Procedures) Act 1986. Neuronal death was quantified with a combination of TUNEL [TdT (terminal deoxyribonucleotidyl transferase) uptake nick end labelling] and neuron counts obtained using the optical disector technique. Sham treatment had no effect upon neuronal death. ALCAR treatment caused a large reduction in the number of TUNEL-positive neurons 2 weeks after axotomy (sham treatment 33/group; low-dose ALCAR 6/group, P=0.132; high-dose ALCAR 3/group, P<0.05), and almost eliminated neuron loss (sham treatment 21%; low-dose ALCAR 0%, P=0.007; high-dose ALCAR 2%, P<0.013). Two months after axotomy the neuroprotective effect of high-dose ALCAR treatment was preserved for both TUNEL counts (no treatment five/group; high-dose ALCAR one/group) and neuron loss (no treatment 35%; high-dose ALCAR -4%, P<0.001). These results provide further evidence for the role of mitochondrial bioenergetic dysfunction in post-traumatic sensory neuronal death, and also suggest that acetyl- L-carnitine may be the first agent suitable for clinical use in the prevention of neuronal death after peripheral nerve trauma.

The potential for CD4 cell increases in HIV-positive individuals who control viraemia with highly active antiretroviral therapy

OBJECTIVES

To study the long-term CD4 cell responses to highly active antiretroviral therapy (HAART) in treatment-naive patients whose viral loads remained below 500 copies/ml for prolonged periods.

DESIGN

A total of 237 patients whose viral loads remained below 500 copies/ml for one year or more. Median follow-up was 1.9 years.

METHODS

CD4 cell counts were analysed to investigate long-term immunological response using mixed-effects models with the slope allowed to change after 1, 12 and 24 months of HAART.

RESULTS

The median baseline CD4 cell count was 175 cells/mm3. After an initial rapid increase in the first month after HAART (97.2 cells/mm3 a month), increases in CD4 cell counts continued less rapidly (11.6 cells/mm3 a month). This increase slowed by 2.4 cells/mm3 a month after one year. CD4 cell counts continued increasing after 2 years, but the rate of increase again slowed (estimated slope at 2 years 5.4 cells/mm3 a month; decrease in slope from year 2 compared with years 1-2 3.7 cell/mm3 a month). A total of 198 out of 211 patients (94%) with measurements at baseline and one year experienced an increase in CD4 cell counts in this interval; 81 and 67% had an increasing slope between 1 and 2 and 2 and 3 years, respectively. By the end of follow-up, CD4 cell counts had increased by 319 cells/mm3, and were more than 500 cells/mm3 in 40% of patients.

CONCLUSION

Although the rate of immune recovery slowed after 2 years, CD4 cell counts rose in most and began to return to levels seen in HIV-negative individuals.