Antiretroviral activity of the anti-CD4 monoclonal antibody TNX-355 in patients infected with HIV type 1

BACKGROUND: We wished to determine the safety and anti-human immunodeficiency virus (HIV) type 1 activity of single doses of TNX-355, a humanized IgG4 anti-CD4 monoclonal antibody with potent activity against HIV-1 in vitro, in HIV-infected subjects. METHODS: Sequential cohorts of 6 HIV-1-infected subjects each received infusions of TNX-355. Data included plasma HIV-1 RNA level, CD4+ T cell count, TNX-355 coating of CD4+ T cells, and serum TNX-355 levels. RESULTS: Dose-related reductions in plasma HIV-1 RNA loads correlated with complete CD4+ T cell coating by TNX-355. Peak median decreases in plasma HIV-1 RNA loads were 0.56, 1.33, and 1.11 log10 copies/mL and occurred on days 4-7, 14, and 21 for the 3.0, 10, and 25 mg/kg doses, respectively. Dose-dependent increases in CD4+ T cell count occurred within 24 h of dosing. CONCLUSIONS: Single doses of TNX-355 reduced plasma HIV-1 RNA loads and increased CD4+ T cell counts in HIV-infected subjects. The further assessment of therapeutic potential awaits data from longer-duration trials.     

Persistent low-level viraemia and virological failure in HIV-1-infected patients treated with highly active antiretroviral therapy

OBJECTIVE: To assess the prognostic significance of persistent low-level viraemia (PLV, defined as persistent plasma viral loads of 51-1000 HIV-1 RNA copies/mL for at least 3 months) in patients who had achieved viral suppression on antiretroviral therapy (ART). METHODS: A retrospective cohort of HIV-infected patients who received ART, were followed-up for > or =12 months, made regular visits to the clinic during which blood tests were performed for an ultrasensitive HIV RNA assay every 3 months, and achieved viral loads <50 copies/mL were evaluated. Virological failure was defined as two consecutive viral load measurements >1000 copies/mL. RESULTS: Of 362 patients, 78 (27.5%) experienced PLV. The demographics of patients with and without PLV were similar. PLV occurred at a mean (+/-standard deviation) of 22.6+/-16.9 months after ART initiation and lasted for 6.4+/-3.4 months. During a median follow-up of 29.5 months, patients with PLV had a higher rate of virological failure (39.7% vs 9.2%; P < 0.001). The median time to failure was 68.4 months [95% confidence interval (CI) 37.0-99.7] for patients with PLV and >72 months for patients without PLV (log rank test, P < 0.001). By Cox regression, patients with PLV had a greater risk of virological failure [hazard ratio (HR) 3.8; 95% CI 2.2-6.4; P < 0.001]. Among patients with PLV, a PLV of >400 copies/mL (HR 3.3; 95% CI 1.5-7.1; P = 0.003) and a history of ART (HR 2.4; 95% CI 1.0-5.7; P = 0.042) predicted virological failure. CONCLUSIONS: PLV is associated with virological failure. Patients with a PLV >400 copies/mL and a history of ART experience are more likely to experience virological failure. Patients with PLV should be considered for treatment optimization and interventional studies.     

TREK-1 channels do not mediate nitrergic neurotransmission in circular smooth muscle from the lower oesophageal sphincter

Background and purpose:

The ionic mechanisms underlying nitrergic inhibitory junction potentials (IJPs) in gut smooth muscle remain a matter of debate. Recently, it has been reported that opening of TWIK-related K⁺ channel 1 (TREK-1) K⁺ channels contributes to the nitrergic IJP in colonic smooth muscle. We investigated the effects of TREK-1 channel blockers on nitrergic neurotransmission in mouse and opossum lower oesophageal sphincter (LOS) circular smooth muscle (CSM).

Experimental approach:

The effects of TREK-1 channel blockers were characterized pharmacologically in murine and opossum gut smooth muscle using conventional intracellular and tension recordings.

Key results:

In LOS, L-methionine depolarized the resting membrane potential (RMP) but did not inhibit the nitrergic IJP. Cumulative application of theophylline hyperpolarized the RMP and inhibited the nitrergic IJP concentration dependently. The induced membrane hyperpolarization was prevented by pre-application of caffeine, but not by 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one. 8-Br-cAMP significantly hyperpolarized membrane potential and increased the amplitude of the nitrergic IJP. In opossum LOS muscle strips, L-methionine increased resting tone but had no effect on nerve-mediated LOS relaxation. On the other hand, theophylline markedly inhibited tone. In CSM from mouse proximal colon, L-methionine caused modest inhibition of nitrergic IJPs.

Conclusions and implications:

TREK-1 channels were not involved in the nitrergic IJP in LOS CSM. Not only does L-methionine have no effect on the nitrergic IJP or LOS relaxation, but the effect of theophylline appears to be due to interruption of Ca²⁺-releasing pathways (i.e. caffeine-like effect) rather than via blockade of TREK-1 channels.     

Presentation and Mortality of Cryptococcal Infection Varies by Predisposing Illness: A Retrospective Cohort Study

BackgroundCryptococcal epidemiology is changing in the modern antiretroviral era, and immune status informs outcomes. We describe the differences in clinical presentation and mortality of cryptococcosis by immune status in the antiretroviral therapy era.MethodsWe conducted a single-center retrospective cohort study of patients diagnosed with cryptococcosis from 2002 through 2017. Data included demographics, clinical features, diagnostics, and mortality.ResultsWe identified 304 patients with Cryptococcus neoformans infections: 105 (35%) were people living with human immunodeficiency virus (HIV), 41 (13%) had a history of transplantation, and 158 (52%) were non-HIV nontransplant (NHNT). Age analysis showed that people living with HIV were younger (40 years) than transplant (53 years) and NHNT (61 years) (P < .001). Fevers and headache were more common in people living with HIV (70% and 57%) than in transplant (49% and 29%) and NHNT (49% and 38%) (P = .003 and P = .001), respectively. Meningitis was more common in people living with HIV (68%) than in transplant recipients (32%) or NHNT (39%, P < .001). Disseminated cryptococcosis was more common in people living with HIV (97%) as compared with transplant (66%) or NHNT (73%) (P < .001). Time to diagnosis from hospitalization was longer for transplant (median 2 days, interquartile range [IQR] ± 9 days) and NHNT patients (median 2 days, IQR ± 7 days) as compared with people living with HIV (median 1 day, IQR ± 2 days) (P = .003). NHNT patients had a higher risk of 90-day mortality (hazard ratio 3.3; 95% confidence interval, 1.9-5.8) as compared with people living with HIV.ConclusionsThe majority of cryptococcosis occurs in NHNT patients. NHNT patients had more localized pulmonary cryptococcosis and significantly higher 90-day mortality. Cryptococcosis in NHNT patients appears to be a distinct entity that needs further study and requires a higher level of clinical suspicion than it currently receives.     

Endocrine complications of human immunodeficiency virus infection: hypogonadism, bone disease and tenofovir-related toxicity

Treatment with highly active antiretroviral therapy (HAART) has revolutionized care of patients with HIV infection. The cost of increased survival has been antiretroviral toxicity and increasing age-related co-morbidities that include significant metabolic issues. Hypogonadism was first described in the setting of advanced AIDS and can be primary or secondary. Data regarding treatment largely concern patients with wasting. Varied syndromes involving bone have been described in patients with HIV including osteonecrosis, low bone mineral density (BMD) and osteoporosis, and rarely osteomalacia. Low BMD leading to osteoporosis is the most common bone pathology and may be as a result of HIV infection, drug toxicity or co-morbidities. However, increasingly fragility fractures are reported in HIV-infected patients, suggesting bone demineralization in this population is of clinical relevance. Further research is required to understand its pathogenesis and determine effective management; however, initiation of antiretroviral therapy seems to accelerate (in the short-term) bone demineralization. One particular antiretroviral agent, tenofovir is widely used and is potentially implicated as having a greater role in long-term bone and renal dysfunction. As this population ages, screening for low BMD will become increasingly more important.     

Vacuum-assisted closure as a surgical assistant in life-threatening necrotizing fasciitis in children

Necrotizing fasciitis is a severe soft tissue infection that can involve skin, subcutaneous fat, fascia and muscle. It can result in devastating sequelae including tissue necrosis, sepsis, toxic shock syndrome, cardiopulmonary collapse and death. To control rapidly spreading necrosis, early diagnosis and aggressive surgical treatment with extensive radical debridement of the affected areas is necessary, as well as systemic administration of broad-spectrum antimicrobials and, very often, intensive care support.The subatmospheric negative pressure dressing has been previously used in acute and complex wounds management. The concept of using vacuum-assisted closure dressing as another management component is presented in the current article.