Effect of pembrolizumab on CD4+ CD25+ , CD4+ LAP+ and CD4+ TIM-3+ T cell subsets.

Tumor immune evasion involves the expansion of avidly proliferating immunosuppressive cells and inhibition of effector T cell proliferation. Immune checkpoints (IC) block the activation pathways of tumor-reactive T cells. IC pathways are often exploited by tumor cells to evade immune destruction, and blocking these pathways through IC inhibitors (ICI) has shown promising results in multiple malignancies. In this study, we investigated the effects of an ICI, pembrolizumab, on various T cell subsets in vitro. We compared the suppressive activity of CD4+ CD25+ regulatory T cells (conventional Treg ) with T cells expressing T cell immunoglobulin-3+ (TIM-3+ ) and latency-associated peptide (LAP)+ T cells. We found that LAP-expressing T cells were more suppressive than conventional Treg , but TIM-3-expressing T cells were not suppressive. Our results show that pembrolizumab does not modulate functions of Treg and mediates its immunostimulatory effects via the release of effector T cells from suppression. These findings may assist in the development of agents designed to intervene in IC pathways to overcome Treg resistance to ICI.

In-vitro effect of pembrolizumab on different T regulatory cell subsets.

Programmed death-1 (PD-1) and interactions with PD-ligand 1 (PD-L1) play critical roles in the tumour evasion of immune responses through different mechanisms, including inhibition of effector T cell proliferation, reducing cytotoxic activity, induction of apoptosis in tumour-infiltrating T cells and regulatory T cell (Treg ) expansion. Effective blockade of immune checkpoints can therefore potentially eliminate these detrimental effects. The aim of this study was to investigate the effect of anti-PD-1 antibody, pembrolizumab, on various Treg subpopulations. Peripheral blood mononuclear cells (PBMC) from healthy donors (HD) and primary breast cancer patients (PBC) were treated in vitro with pembrolizumab, which effectively reduced PD-1 expression in both cohorts. We found that PD-1 was expressed mainly on CD4+ CD25+ T cells and pembrolizumab had a greater effect on PD-1 expression in CD4+ CD25- T cells, compared to CD4+ CD25+ cells. In addition, pembrolizumab did not affect the expression levels of Treg -related markers, including cytotoxic T lymphocyte antigen-4 (CTLA-4), CD15s, latency-associated peptide (LAP) and Ki-67. Moreover, we report that CD15s is expressed mainly on forkhead box P3 (FoxP3)- Helios+ Treg in HD, but it is expressed on FoxP3+ Helios- Treg subset in addition to FoxP3- Helios+ Treg in PBC. Pembrolizumab did not affect the levels of FoxP3+/- Helios+/- Treg subsets in both cohorts. Taken together, our study suggests that pembrolizumab does not affect Treg or change their phenotype or function but rather blocks signalling via the PD-1/PD-L1 axis in activated T cells.

Familial neck-tongue syndrome.

Neck-tongue syndrome is an uncommon clinical entity characterized by brief attacks of intense unilateral stabbing pain in the upper neck or occipital region upon sudden rotation of the head, accompanied by ipsilateral numbness of the tongue. Eight patients, 5 teenagers and 3 adults, with neck-tongue syndrome are presented. Each of the 5 adolescents had normal examinations and normal neuroimaging. The 3 adults were parents of the affected children and had experienced transient symptoms during their adolescence suggesting an autosomal dominant inheritance pattern.

Children's ibuprofen suspension for the acute treatment of pediatric migraine.

OBJECTIVE: To compare the efficacy of a single over-the-counter dose (7.5 mg/kg, p.o.) of children's ibuprofen suspension vs. placebo for the acute treatment of pediatric migraine. BACKGROUND: Migraine occurs in 4% of young children. There is a paucity of controlled clinical research in the treatment of childhood migraine and there are currently no approved drugs in the USA for treatment of migraine in children < or = 12 years of age. The purpose of this study is to assess the efficacy and tolerability of a single OTC dose of ibuprofen suspension for the acute treatment of childhood migraine. METHODS: Prospective, double-blind, placebo-controlled, parallel group, randomized study of children 6-12 yrs with migraine (I.H.S.-R 1997) treating 1 attack with a 7.5 mg/kg liq. ibuprofen vs matching placebo. Efficacy measures: (1). Headache severity based upon a 4 pt scale (severe, mod., mild, no headache) at 30, 60, 90, 120, 180 and 240 minutes post dose, and (2). nausea, vomiting, and photo/phonophobia at 120 min. The 1 degrees endpoint was cumulative % of responders (severe or mod. headache reduced to mild or none) by 120 minutes. Secondary endpoints were headache recurrence within 4-24 hours and need for rescue medicines within 4 hours. RESULTS: 138 enrolled; 84 treated/completed diary. 45 active agent, 39 placebo. The 2 groups were comparable (active: placebo) - Ages: 9: 9.1, gender boy/girl - 1.25: 1.6, and diagnosis: migraine w/o aura - 86%: 79%. Concomitant use of prophylactic Rx: 24%: 10% (Table 3). Nausea was eliminated in 60% of the ibuprofen treated patients and 39% of the placebo group (p<0.001). Vomiting, photophobia and phonophobia had marginal, but not statistically significant, decreases at 2 hours. A striking gender difference was noted (Table 4): No AE's were reported. CONCLUSION: Children's ibuprofen suspension at an OTC dose of 7.5 mg/kg is an effective and well-tolerated agent for pain relief in the acute treatment of childhood migraine, particularly in boys. There is a striking difference in gender response rates and placebo responder rates between girls and boys. The boys responded at a statistically significant rate, and girls failed to do so because of a very high placebo responder rate. Multi-center trials are recommended.