Continuous Infusion Interleukin-2 and Antihistamines in Metastatic Kidney Cancer

Histamine in cancer immunology and immunotherapy. Current status and new perspectives

Cancer is the second leading cause of death globally and its incidence and mortality are rapidly increasing worldwide. The dynamic interaction of immune cells and tumor cells determines the clinical outcome of cancer. Immunotherapy comes to the forefront of cancer treatments, resulting in impressive and durable responses but only in a fraction of patients. Thus, understanding the characteristics and profiles of immune cells in the tumor microenvironment (TME) is a necessary step to move forward in the design of new immunomodulatory strategies that can boost the immune system to fight cancer. Histamine produces a complex and fine-tuned regulation of the phenotype and functions of the different immune cells, participating in multiple regulatory responses of the innate and adaptive immunity. Considering the important actions of histamine-producing immune cells in the TME, in this review we first address the most important immunomodulatory roles of histamine and histamine receptors in the context of cancer development and progression. In addition, this review highlights the current progress and foundational developments in the field of cancer immunotherapy in combination with histamine and pharmacological compounds targeting histamine receptors.

Pathophysiological Roles of Histamine Receptors in Cancer Progression: Implications and Perspectives as Potential Molecular Targets

High levels of histamine and histamine receptors (HRs), including H1R~H4R, are found in many different types of tumor cells and cells in the tumor microenvironment, suggesting their involvement in tumor progression. This review summarizes the latest evidence demonstrating the pathophysiological roles of histamine and its cognate receptors in cancer biology. We also discuss the novel therapeutic approaches of selective HR ligands and their potential prognostic values in cancer treatment. Briefly, histamine is highly implicated in cancer development, growth, and metastasis through interactions with distinct HRs. It also regulates the infiltration of immune cells into the tumor sites, exerting an immunomodulatory function. Moreover, the effects of various HR ligands, including H1R antagonists, H2R antagonists, and H4R agonists, on tumor progression in many different cancer types are described. Interestingly, the expression levels of HR subtypes may serve as prognostic biomarkers in several cancers. Taken together, HRs are promising targets for cancer treatment, and HR ligands may offer novel therapeutic potential, alone or in combination with conventional therapy. However, due to the complexity of the pathophysiological roles of histamine and HRs in cancer biology, further studies are warranted before HR ligands can be introduced into clinical settings.

Histamine type 2 receptor expression on peripheral blood regulatory lymphocytes in patients with allergic rhinitis treated with specific immunotherapy

BACKGROUND

Both histamine H1- and H2-receptors (H2R) were found on regulatory T (Treg) cells; however, there is a paucity of information regarding the role of H2R in Treg function. This study aimed to investigate the effects of natural allergen stimulation and specific immunotherapy (SIT) on H2R expression in Treg cells in patients with allergic rhinitis (AR).

METHODS

In this prospective, double-blind, placebo-controlled study 41 patients with AR were screened for 1 year and treated with SIT (n = 21) or placebo (n = 20) for the next 2 years. Fifteen healthy subjects were included as a control. Subsets of Treg cells that expressed H2R were assessed annually in the blood by flow cytometry: before, at the height of the pollen season, and after, at the end of the pollen season. In addition, total nasal symptom score, the use of rescue medication, and nasal eosinophilia were evaluated.

RESULTS

Treg cells of AR patients slightly up-regulate H2R out of the pollen season. Natural allergen stimulation results in prompt up-regulation of H2R within these cells. SIT significantly decreased the number of Treg cells with increased expression of H2R in the blood exclusively at the height of pollen season, which, however, had no impact on the expression of H2R in Treg cells. SIT improved significantly the symptom score, rescue medication use, and decreased nasal eosinophilia.

CONCLUSION

Natural pollen exposure results in up-regulation of H2R in Treg cells. Immunotherapy might transiently decrease the number of Treg-H2R(+) cells in the blood, which may be associated with their migration to the peripheral tissues. This study was part of the clinical trial registered in www.clinicaltrials.gov.

Continuous infusion interleukin-2 and famotidine in metastatic kidney cancer

Infusional interleukin-2 (IL-2) is able to elicit lymphokine-activated killer cell (LAK) cytotoxicity against kidney cancer in vitro and in vivo. Famotidine may be able to augment LAK cytotoxicity against neoplastic cells. Fifteen (15) patients were treated with continuous-infusion IL-2 (9-18 MIU/m2/24 hours) for 72 hours and famotidine 20 mg intravenously twice per day. Cycles were repeated every 3 weeks. These patients had a median age of 60 years (range, 29-72), had a median performance status of 1 (range, 0-1), and had metastatic sites, including lung, bone, lymph node, and liver. The most common toxicities of this regimen were hypophosphatemia, fever, nausea/emesis, rigors, elevated creatinine, and hypomagnesemia. One (1) complete and 6 partial responses have been seen (47% response rate). The median duration of response is 9 months. The median survival for all patients is 20 months. Five (5) patients are alive at a median of 36+ months. This combination of infusional IL-2 with famotidine is active in metastatic kidney cancer.