A highly virulent variant of HIV-1 circulating in the Netherlands

We discovered a highly virulent variant of subtype-B HIV-1 in the Netherlands. One hundred nine individuals with this variant had a 0.54 to 0.74 log₁₀ increase (i.e., a ~3.5-fold to 5.5-fold increase) in viral load compared with, and exhibited CD4 cell decline twice as fast as, 6604 individuals with other subtype-B strains. Without treatment, advanced HIV-CD4 cell counts below 350 cells per cubic millimeter, with long-term clinical consequences-is expected to be reached, on average, 9 months after diagnosis for individuals in their thirties with this variant. Age, sex, suspected mode of transmission, and place of birth for the aforementioned 109 individuals were typical for HIV-positive people in the Netherlands, which suggests that the increased virulence is attributable to the viral strain. Genetic sequence analysis suggests that this variant arose in the 1990s from de novo mutation, not recombination, with increased transmissibility and an unfamiliar molecular mechanism of virulence.

The dolutegravir/valproic acid drug-drug interaction is primarily based on protein displacement

OBJECTIVES

The dolutegravir/valproic acid drug-drug interaction (DDI) is suggested to be caused by protein displacement. Here, we assess the underlying mechanism.

METHODS

Participants in a randomized controlled trial investigating valproic acid as an HIV latency reversing agent were recruited in a predefined pharmacokinetic substudy if they were on once-daily 50 mg dolutegravir-containing combination ART (cART) for >12 months with a plasma HIV-RNA <50 copies/mL (trial registration: ClinicalTrials.gov NCT03525730). Participants were randomized to receive 30 mg/kg/day valproic acid orally (divided into two equal doses) for 14 days or not. Total and unbound dolutegravir concentrations were measured on day 0 (before intake of valproic acid and 6 h after intake of valproic acid) and on days 1, 7, 14 and 42. Intra- and inter-subject dolutegravir concentrations and geometric means (GMs) were evaluated.

RESULTS

Six of 10 participants on dolutegravir were randomized to receive valproic acid. During 14 days of valproic acid treatment, the GM total dolutegravir concentration decreased sharply from 1.36 mg/L on day 0 to 0.85, 0.31 and 0.20 mg/L on days 0, 1, 7 and 14, respectively, while total dolutegravir concentrations in the controls remained comparable during the same period: 1.27-1.49 mg/L. We observed a parallel increase in unbound dolutegravir fractions ranging from 0.39% to 0.58% during valproic acid administration, compared with 0.25% to 0.28% without valproic acid. Unbound dolutegravir concentrations were above the established in vitro EC90 value for unbound dolutegravir in 85% of the tested samples.

CONCLUSIONS

This study confirms protein displacement as the main mechanism for this DDI, although additional mechanisms might be involved too. If dolutegravir is taken with food, this DDI is probably not clinically relevant.

How to: Establish and run a stool bank

BACKGROUND

Since 2013, several stool banks have been developed following publications reporting on clinical success of 'faecal microbiota transplantation' (FMT) for recurrent Clostridium difficile infections (CDI). However, protocols for donor screening, faecal suspension preparation, and transfer of the faecal suspension differ between countries and institutions. Moreover, no European consensus exists regarding the legislative aspects of the faecal suspension product. Internationally standardized recommendations about the above mentioned aspects have not yet been established.

OBJECTIVE

In 2015, the Netherlands Donor Feces Bank (NDFB) was founded with the primary aim of providing a standardized product for the treatment of patients with recurrent CDI in the Netherlands. Standard operation procedures for donor recruitment, donor selection, donor screening, and production, storage, and distribution of frozen faecal suspensions for FMT were formulated.

RESULTS AND DISCUSSION

Our experience summarized in this review addresses current donor recruitment and screening, preparation of the faecal suspension, transfer of the faecal microbiota suspension, and the experiences and follow-up of the patients treated with donor faeces from the NDFB.

Low prevalence of Blastocystis sp. in active ulcerative colitis patients

Ulcerative colitis (UC) is thought to originate from a disbalance in the interplay between the gut microbiota and the innate and adaptive immune system. Apart from the bacterial microbiota, there might be other organisms, such as parasites or viruses, that could play a role in the aetiology of UC. The primary objective of this study was to compare the prevalence of Blastocystis sp. in a cohort of patients with active UC and compare that to the prevalence in healthy controls. We studied patients with active UC confirmed by endoscopy included in a randomised prospective trial on the faecal transplantation for UC. A cohort of healthy subjects who served as donors in randomised trials on faecal transplantation were controls. Healthy subjects did not have gastrointestinal symptoms and were extensively screened for infectious diseases by a screenings questionnaire, extensive serologic assessment for viruses and stool analysis. Potential parasitic infections such as Blastocystis were diagnosed with the triple faeces test (TFT). The prevalence of Blastocystis sp. were compared between groups by Chi-square testing. A total of 168 subjects were included, of whom 45 had active UC [median age 39.0 years, interquartile range (IQR) 32.5–49.0, 49 % male] and 123 were healthy subjects (median age 27 years, IQR 22.0–37.0, 54 % male). Blastocystis sp. was present in the faeces of 40/123 (32.5 %) healthy subjects and 6/45 (13.3 %) UC patients (p = 0.014). Infection with Blastocystis is significantly less frequent in UC patients as compared to healthy controls.

Fecal transplant: a safe and sustainable clinical therapy for restoring intestinal microbial balance in human disease?

Recent studies have suggested an association between intestinal microbiota composition and human disease, however causality remains to be proven. With hindsight, the application of fecal transplantation (FMT) does indeed suggest a causal relation between interfering with gut microbiota composition and a resultant cure of several disease states. In this review, we aim to show the available evidence regarding the involvement of intestinal microbiota and human (autoimmune) disease. Moreover, we refer to (mostly case report) studies showing beneficial or adverse effects of fecal transplantation on clinical outcomes in some of these disease states. If these findings can be substantiated in larger randomized controlled double blind trials also implementing gut microbiota composition before and after intervention, fecal transplantation might provide us with novel insights into causally related intestinal microbiota, that might be serve as future diagnostic and treatment targets in human disease.

Struggling with recurrent Clostridium difficile infections: is donor faeces the solution?

Patients with recurrent Clostridium difficile infections (CDI) in hospitals and the community constitute an increasing treatment problem. While most patients with a first infection respond to either metronidazole or oral vancomycin, therapy in recurrent C. difficile infections tends to fail repeatedly. Lack of alternative treatment options can be a tremendous burden, both to patients and their treating physicians. Most guidelines recommend prolonged oral vancomycin pulse and or tapering schedules, but evidence-based treatment strategies are lacking. The role of immunoglobulins, whey prepared from vaccinated cows, probiotics or other antibiotics is unclear. Since 1958 several case series and case reports describe a treatment strategy where faecal infusions are successfully given for the treatment of recurrent CDI. Restoring intestinal flora has been historically thought of as the mechanism responsible for cure in these patients. In the literature, more than 150 patients have received faeces from a healthy donor, either infused through an enema, or through a nasoduodenal or nasogastric tube. We summarise the literature regarding treatment with donor faeces for recurrent CDI, and introduce the FECAL trial, currently open for inclusion.

[Treatment of recurrent Clostridium difficile-associated diarrhoea with a suspension of donor faeces]

OBJECTIVE

To study the effect of treating recurrent Clostridium difficile-associated diarrhoea (CDAD) with a suspension of donor faeces.

DESIGN

Uncontrolled interventional study.

METHOD

Patients that, despite adequate antibiotic therapy, had developed at least 2 recurrences ofCDAD, including at least one recurrence that had been treated with a vancomycin tapering regimen, were included in the study. Relatives or volunteers served as faeces donor. All donors were previously examined for the presence of HIV, hepatitis B- and C-virus, and acute infection with cytomegalovirus or Epstein-Barr virus. The donor faeces were examined for the presence of C. difficile, Yersinia, Campylobacter, Shigella, Salmonella, and parasites. Before the infusion of donor faeces, the patients were treated for 4 days with vancomycin 500 mg q.i.d., followed by colon lavage. The suspension of 150 g of donor faeces dissolved in 300-400 ml of NaCl was infused into the jejunum via a duodenal catheter or into the caecum via colonoscopy.

RESULTS

7 CDAD patients were included and treated, including 2 with the hypervirulent C. difficile-strain PCR ribotype 027, toxinotype III. In 5 patients, the defaecation frequency returned to normal almost immediately after treatment and the cultures and toxin tests for C. difficile were repeatedly negative. In the remaining 2 patients, the treatment was successful after a repeated infusion of faeces from a different donor.

CONCLUSION

Treatment with donor faeces seems promising for patients who develop repeated recurrences despite adequate therapy and could be valuable in the future during (local) epidemics of the PCR ribotype 027 strain. A randomised nationwide study (FECAL trial) has been started in order to determine the efficacy of this treatment.

Rat-bite fever

A 23-year-old woman presented with fever, arthralgias and a skin rash. She possessed nine pet rats, and denied that she had been bitten. Blood culture was positive for Streptobacillus moniliformis, which can cause rat-bite fever. The patient fully recovered after treatment with clarithromycin.

Flavonoids: a review of probable mechanisms of action and potential applications

The aim of this review, a summary of the putative biological actions of flavonoids, was to obtain a further understanding of the reported beneficial health effects of these substances. Flavonoids occur naturally in fruit, vegetables, and beverages such as tea and wine. Research in the field of flavonoids has increased since the discovery of the French paradox,ie, the low cardiovascular mortality rate observed in Mediterranean populations in association with red wine consumption and a high saturated fat intake. Several other potential beneficial properties of flavonoids have since been ascertained. We review the different groups of known flavonoids, the probable mechanisms by which they act, and the potential clinical applications of these fascinating natural substances.