Efficacy and safety of Bacillus clausii (O/C, N/R, SIN, T) probiotic combined with oral rehydration therapy (ORT) and zinc in acute diarrhea in children: a randomized, double-blind, placebo-controlled study in India

Background

Childhood diarrhea remains a major disease burden, particularly in developing countries, and is a leading cause of death in children aged < 5 years, worldwide. Treatment of acute diarrhea now includes probiotics to potentially reduce the duration and severity of the illness. This phase 3, randomized, placebo-controlled, double-blind study assessed the efficacy and safety of four strains (O/C, N/R, SIN, T) of Bacillus clausii probiotic (Enterogermina®) plus oral rehydration therapy (ORT) and zinc, versus placebo plus ORT and zinc, in infants and children in India with acute moderate diarrhea.

Methods

Patients aged 6 months to 5 years with acute moderate diarrhea (WHO 2005 definition) of < 48 h’ duration were randomly assigned to receive one mini bottle of either polyantibiotic-resistant B. clausii (oral suspension of 2 billion spores per 5 mL bottle) or matching placebo twice daily (morning and evening) for 5 days. Exclusion criteria included known hypersensitivity to B. clausii or excipients in the study treatment, or to other probiotics. Patients were admitted to hospital from Day 1 and discharged ≥6 h after diarrhea resolution, or a maximum of 5 days. The primary endpoint was duration of acute diarrhea from randomization to recovery. Secondary endpoints included frequency of stools, diapers with stools, or dehydration status.

Results

In total, 457 patients were randomized; 454 were treated. Similar proportions of patients showed recovery from diarrhea over the 120 h after randomization (97.0% in the B. clausii group [n = 227]; 98.0% on placebo [n = 227]). Median time to recovery was also similar: 42.83 (95% CI: 40.90–44.90) hours for B. clausii and 42.13 (95% CI: 39.80–43.87) hours for placebo. However, no statistically significant difference was observed between groups (hazard ratio = 0.93 [95% CI: 0.77–1.13]; p = 0.6968); nor were there statistically significant differences between groups for the secondary endpoints. Treatment with B. clausii was well tolerated with incidence of adverse events (9.7%) similar to that for placebo (12.3%).

Conclusions

No significant difference in efficacy between B. clausii and placebo was demonstrated. Sample size may have been inadequate to allow detection of a between-group difference in efficacy, given the mild/moderate severity (only ~ 20% of patients had nausea/vomiting or abdominal pains) and short duration of disease among subjects, the relatively late start of treatment (most were already on Day 2 of their disease episode when study treatment started) and the effectiveness of the standard of care with ORT and zinc in both treatment groups.

Trial registration

CTRI number CTRI/2018/10/016053. Registered on 17 October 2018. EudraCT number 2016-005165-31. Registered 14 May 2020 (retrospectively registered).

Supplementary Information

The online version contains supplementary material available at 10.1186/s40794-022-00166-6.

Efficacy and Safety of Sarilumab for the Treatment of Posterior Segment Noninfectious Uveitis (SARIL-NIU):: The Phase 2 SATURN Study

PURPOSE

To assess efficacy and safety of sarilumab, a human anti-interleukin-6 receptor antibody, for treatment of posterior segment noninfectious uveitis (NIU).

DESIGN

Randomized, double-masked, placebo-controlled, phase 2 study.

PARTICIPANTS

Fifty-eight patients (eyes) with noninfectious intermediate, posterior, or panuveitis.

METHODS

Eyes received treatment every 2 weeks for 16 weeks with subcutaneous sarilumab 200 mg or placebo.

MAIN OUTCOME MEASURES

The primary end point was the proportion of patients with ≥2-step reduction in vitreous haze (VH) on the Miami scale or with a reduction of systemic corticosteroids (prednisolone or equivalent) to a dose of <10 mg/day at week 16. Primary end point was based on VH evaluation by a central reading center. Investigator evaluation of VH was a prespecified, planned secondary analysis.

RESULTS

At week 16, proportion of patients taking sarilumab or placebo with ≥2-step reduction in VH or corticosteroid dose <10 mg/day was 46.1% vs. 30.0% (P = 0.2354) based on central reading center assessment of VH and 64.0% vs. 35.0% (P = 0.0372) based on investigator assessment of VH, respectively. In the subgroup of eyes with VH grade ≥2 at baseline, the mean VH reduction from baseline to week 16 was significantly greater with sarilumab vs. placebo regardless of assessment by the central reading center (-2.1 [n = 11] vs. -1.7 [n = 3], respectively; P = 0.0255) or investigator (-2.5 [n = 19] vs. -1.2 [n = 11], respectively; P = 0.0170). The mean best-corrected visual acuity gain from baseline to week 16 was greater with sarilumab vs. placebo in the overall population (8.9 vs. 3.6 letters, respectively; P = 0.0333) and in the subgroup of eyes with central subfield thickness (CST) ≥300 μm at baseline (12.2 [n = 13] vs. 2.1 [n = 7] letters, respectively; P = 0.0517). Corresponding changes in CST were -46.8 vs. +2.6 μm (P = 0.0683) in the overall population and -112.5 [n = 13] vs. -1.8 [n = 6] μm (P = 0.1317) in the subgroup of eyes with CST ≥300 μm at baseline, respectively. The most common ocular adverse events were worsening of uveitis (0 [placebo] and 3 [sarilumab] patients) and retinal infiltrates (1 [placebo] and 2 [sarilumab] patients).

CONCLUSIONS

Subcutaneous sarilumab may provide clinical benefits in the management of NIU of the posterior segment, especially in eyes with uveitic macular edema.

Intravitreous injection of AAV2-sFLT01 in patients with advanced neovascular age-related macular degeneration: a phase 1, open-label trial

BACKGROUND

Long-term intraocular injections of vascular endothelial growth factor (VEGF)-neutralising proteins can preserve central vision in many patients with neovascular age-related macular degeneration. We tested the safety and tolerability of a single intravitreous injection of an AAV2 vector expressing the VEGF-neutralising protein sFLT01 in patients with advanced neovascular age-related macular degeneration.

METHODS

This was a phase 1, open-label, dose-escalating study done at four outpatient retina clinics in the USA. Patients were assigned to each cohort in order of enrolment, with the first three patients being assigned to and completing the first cohort before filling positions in the following treatment groups. Patients aged 50 years or older with neovascular age-related macular degeneration and a baseline best-corrected visual acuity score of 20/100 or less in the study eye were enrolled in four dose-ranging cohorts (cohort 1, 2 × 10⁸ vector genomes (vg); cohort 2, 2 × 10⁹ vg; cohort 3, 6 × 10⁹ vg; and cohort 4, 2 × 10¹⁰ vg, n=3 per cohort) and one maximum tolerated dose cohort (cohort 5, 2 × 10¹⁰ vg, n=7) and followed up for 52 weeks. The primary objective of the study was to assess the safety and tolerability of a single intravitreous injection of AAV2-sFLT01, through the measurement of eye-related adverse events. This trial is registered with ClinicalTrials.gov, number NCT01024998.

FINDINGS

19 patients with advanced neovascular age-related macular degeneration were enrolled in the study between May 18, 2010, and July 14, 2014. All patients completed the 52-week trial period. Two patients in cohort 4 (2 × 10¹⁰ vg) experienced adverse events that were possibly study-drug related: pyrexia and intraocular inflammation that resolved with a topical steroid. Five of ten patients who received 2 × 10¹⁰ vg had aqueous humour concentrations of sFLT01 that peaked at 32·7-112·0 ng/mL (mean 73·7 ng/mL, SD 30·5) by week 26 with a slight decrease to a mean of 53·2 ng/mL at week 52 (SD 17·1). At baseline, four of these five patients were negative for anti-AAV2 serum antibodies and the fifth had a very low titre (1:100) of anti-AAV2 antibodies, whereas four of the five non-expressers of sFLT01 had titres of 1:400 or greater. In 11 of 19 patients with intraretinal or subretinal fluid at baseline judged to be reversible, six showed substantial fluid reduction and improvement in vision, whereas five showed no fluid reduction. One patient in cohort 5 showed a large decrease in vision between weeks 26 and 52 that was not thought to be vector-related.

INTERPRETATION

Intravitreous injection of AAV2-sFLT01 seemed to be safe and well tolerated at all doses. Additional studies are needed to identify sources of variability in expression and anti-permeability activity, including the potential effect of baseline anti-AAV2 serum antibodies.

FUNDING

Sanofi Genzyme, Framingham, MA, USA.

NMR solution structure of murine CCL20/MIP-3alpha, a chemokine that specifically chemoattracts immature dendritic cells and lymphocytes through its highly specific interaction with the beta-chemokine receptor CCR6

CCL20/MIP-3alpha is a beta-chemokine expressed in the thymus, skin, and intestinal epithelial cells that exclusively binds and activates the CCR6 receptor in both mice and humans. The strict receptor binding specificity of CCL20 is exceptional; other chemokines and their receptors bind promiscuously with multiple partners. Toward determining the structural basis for the selective receptor specificity of CCL20, we have determined its three-dimensional structure by 1H NMR spectroscopy. CCL20 exhibits the same monomeric structure previously described for other chemokines: a three-stranded beta-sheet and an overlying alpha-helix. The CCL20 receptor selectivity could arise from the rigid conformation of the N-terminal DCCL motif as well as the groove between the N-loop and the beta2-beta3 hairpin, which is significantly narrower in CCL20 than in other chemokines. Similar structural features are seen in human beta-defensin 2, a small nonchemokine polypeptide reported to selectively bind and activate CCR6, which stresses their importance for the specific binding of both CCL20 and beta-defensin 2 to CCR6. CCL20's structure will be useful to design tools aimed to modulate its important biological functions.

CCR6-deficient mice have impaired leukocyte homeostasis and altered contact hypersensitivity and delayed-type hypersensitivity responses

CCR6 expression in dendritic, T, and B cells suggests that this beta-chemokine receptor may regulate the migration and recruitment of antigen-presenting and immunocompetent cells during inflammatory and immunological responses. Here we demonstrate that CCR6-/- mice have underdeveloped Peyer's patches, in which the myeloid CD11b+ CD11c+ dendritic-cell subset is not present in the subepithelial dome. CCR6-/- mice also have increased numbers in T-cell subpopulations within the intestinal mucosa. In 2,4-dinitrofluorobenzene-induced contact hypersensitivity (CHS) studies, CCR6-/- mice developed more severe and more persistent inflammation than wild-type (WT) animals. Conversely, in a delayed-type hypersensitivity (DTH) model induced with allogeneic splenocytes, CCR6-/- mice developed no inflammatory response. The altered responses seen in the CHS and DTH assays suggest the existence of a defect in the activation and/or migration of the CD4(+) T-cell subsets that downregulate or elicit the inflammation response, respectively. These findings underscore the role of CCR6 in cutaneous and intestinal immunity and the utility of CCR6-/- mice as a model to study pathologies in these tissues. This article was published online in advance of the print edition. The date of publication is available from the JCI website, http://www.jci.org.

Down-regulation of the beta-chemokine receptor CCR6 in dendritic cells mediated by TNF-alpha and IL-4

Chemokines are involved in the control of dendritic cell (DC) trafficking, which is critical for the immune response. We have generated DC from human umbilical cord blood CD34+ progenitors cultured with granulocyte-macrophage colony-stimulating factor, tumor necrosis factor alpha (TNF-alpha), and stem cell factor. Using an anti-CCR6 monoclonal antibody, we observed that these cells showed maximum expression of this beta-chemokine receptor when they were immature, as determined by their relatively low expression of several DC maturation markers such as CD1a, CD11c, CD14, CD40, CD80, and CD83. Immature DC responded strongly to macrophage inflammatory protein-3alpha (MIP-3alpha), the CCR6 ligand, in migration and calcium mobilization assays. CCR6 expression decreased in parallel with the DC maturation induced by prolonged TNF-alphaq treatments. Interleukin-4 was also able to decrease CCR6 protein levels. Our findings suggest that the MIP-3alpha/CCR6 interaction plays an important role in the trafficking of immature DC to chemokine production sites such as injured or inflamed peripheral tissues, where DC undergo maturation on contact with antigens.

Cutting edge: identification of the orphan chemokine receptor GPR-9-6 as CCR9, the receptor for the chemokine TECK

Thymus-expressed chemokine (TECK) has been reported to chemoattract dendritic cells, thymocytes, and activated macrophages. Here, we show that TECK is a specific agonist for a human orphan receptor called GPR-9-6. We have determined the cDNA sequence of human GPR-9-6 and cloned the corresponding murine cDNA. Human and murine GPR-9-6 expression is very high in the thymus and low in lymph nodes and spleen. RT-PCR analysis of murine GPR-9-6 expression on murine FACS-sorted thymocyte subpopulations showed that this gene is expressed in both immature and mature T cells. Additions of human or murine TECK to HEK 293/human GPR-9-6 and HEK 293/murine GPR-9-6 transfectants provoked intracytoplasmic calcium mobilization. Human TECK also induced the in vitro migration of HEK 293/human GPR-9-6 cells. These results confirm that GPR-9-6 is a specific receptor for TECK. According to the established nomenclature system, we propose to rename GPR-9-6 as CC chemokine receptor 9 (CCR9).

Functional and phenotypic analysis of thymic B cells: role in the induction of T cell negative selection

The phenotype of mouse thymic B cells and their capacity to induce T cell negative selection in vitro were analyzed. Thymic B cells expressed B cell markers such as IgM, Fc gamma receptor, CD44, heat-stable antigen, LFA-1 and CD40. In addition, they were positive for the activation molecule CD69 and displayed high levels of B7-2. Although thymic B cells expressed CD5 on their surface, no CD5-specific mRNA was detected. Moreover, thymic B cells induced a stronger deletion of TCR-transgenic (TG) thymocytes than splenic B cells, which had low CD69 and B7-2 levels. Interestingly, CD40-activated splenic B cells up-regulated CD69 and B7-2 and acquired a capacity to induce T cell deletion comparable to that of thymic B cells. Moreover, thymic B cells from CD40-deficient mice displayed lower CD69 and B7-2 levels than control thymic B cells, and lower capacity to induce the deletion of TCR TG thymocytes. These results support the hypothesis that CD40-mediated activation of thymic B cells determines a high efficiency of antigen presentation, suggesting that within the thymus B cells may play an important role in the elimination of autoreactive thymocytes.

Molecular cloning, functional characterization and mRNA expression analysis of the murine chemokine receptor CCR6 and its specific ligand MIP-3alpha

We have cloned the murine CCR6 receptor and its ligand, the beta-chemokine mMIP-3alpha. Calcium mobilization assays performed with mCCR6 transfectants showed significant responses upon addition of mMIP-3alpha. Murine MIP-3alpha RNA is expressed in thymus, small intestine and colon, whereas mCCR6 RNA is expressed in spleen and lymph nodes. RT-PCR analysis of FACS-sorted lymphoid and antigen presenting cell subsets showed mCCR6 expression mainly in B cells, CD8- splenic dendritic cells and CD4+ T cells. The cloning and functional characterization of the mCCR6 and mMIP-3alpha will allow the study of the role of these proteins in mouse models of inflammation and immunity.

Identification of CCR8 as the specific receptor for the human beta-chemokine I-309: cloning and molecular characterization of murine CCR8 as the receptor for TCA-3

Chemokine receptor-like 1 (CKR-L1) was described recently as a putative seven-transmembrane human receptor with many of the structural features of chemokine receptors. To identify the ligand of CKR-L1, we have studied chemokine-induced calcium mobilization in 293 cells transfected with CKR-L1. Of 20 different chemokines tested, only I-309 was able to elicit a significant calcium mobilization. In addition, I-309 induced the transfectants to migrate in vitro. As expected for chemokine receptor-mediated effects, pertussis toxin, but not cholera toxin, inhibited both the calcium flux and migration of the CKR-L1 transfectants in response to I-309. All of these data support the conclusion that I-309 is a functional ligand for CKR-L1. According to the current chemokine receptor nomenclature, we have designated this gene as CCR8. The murine CCR8 (mCCR8) gene was cloned, and its predicted amino acid sequence showed a 71% identity with that of human CCR8. As human CCR8, mCCR8 is expressed in thymus. Both I-309 and its murine homologue TCA-3 were able to induce calcium mobilization in transiently transfected 293-EBNA cells expressing mCCR8. The affinity of the binding of 125I-labeled TCA-3 to mCCR8 was high (Kd approximately 2 nM); the binding was prevented completely by an excess of cold TCA-3, and only partially competed (40%) by I-309. The identification of I-309 and TCA-3 as the functional ligands for CCR8 receptors will help to unravel the role of these proteins in physiologic and pathologic situations.

Molecular cloning and RNA expression of two new human chemokine receptor-like genes

Two new human genes encoding putative G protein-coupled receptors were cloned from genomic DNA following a degenerate PCR strategy. The predicted amino acid sequences of the proteins encoded by these genes have the characteristic motifs of chemokine receptors. This prompted us to name these genes CKR-L1 and CKR-L3. Nevertheless, the identification of their ligands has not been possible using 16 human chemokines in three different assays. The RNA expression pattern of CKR-L1 and CKR-L3 is also similar to that generally found for chemokine receptors. To a different extent, these genes are expressed in spleen, lymph nodes, and CD4+, CD8+ and CD19+ lymphocytes. CKR-L1 expression was also detected in monocyte/macrophages. The homology to chemokine receptors suggests that CKR-L1 belongs to the family of beta chemokine receptors, while CKR-L3 is more similar to alpha chemokine receptors.

Papulacandin B resistance in budding and fission yeasts: isolation and characterization of a gene involved in (1,3)beta-D-glucan synthesis in Saccharomyces cerevisiae

Papulacandin B, an antifungal agent that interferes with the synthesis of yeast cell wall (1,3)beta-D-glucan, was used to isolate resistant mutants in Schizosaccharomyces pombe and Saccharomyces cerevisiae. The resistance to papulacandin B always segregated as a recessive character that defines a single complementation group in both yeasts (pbr1+ and PBR1, respectively). Determination of several kinetic parameters of (1,3)beta-D-glucan synthase activity revealed no differences between S. pombe wild-type and pbr1 mutant strains except in the 50% inhibitory concentration for papulacandin B of the synthases (about a 50-fold increase in mutant activity). Inactivation of the synthase activity of both yeasts after in vivo treatment with the antifungal agent showed that mutant synthases were more resistant than the corresponding wild-type ones. Detergent dissociation of the S. pombe synthase into soluble and particulate fractions and subsequent reconstitution indicated that the resistance character of pbr1 mutants resides in the particulate fraction of the enzyme. Cloning and sequencing of PBR1 from S. cerevisiae revealed a gene identical to others recently reported (FKS1, ETG1, CWH53, and CND1). Its disruption leads to reduced levels of both (1,3)beta-D-glucan synthase activity and the alkali-insoluble cell wall fraction. Transformants containing the PBR1 gene reverse the defect in (1,3)beta-D-glucan synthase. It is concluded that Pbr1p is probably part of the (1,3)beta-D-glucan synthase complex.