Dipeptidyl peptidase-4 inhibitor might exacerbate Graves' disease: A multicenter observational case-control study.

Dipeptidyl peptidase-4 (DPP-4), namely CD26, is expressed on the surface of immune cells, suggesting that inhibition of DPP-4 might affect the immune system. The current multicenter observational case-control study was carried out to investigate the effects of DPP-4 inhibitor (DPP-4i) administration on Graves' disease (GD) activity. This study comprised patients with GD and type 2 diabetes, who were administered an oral hypoglycemic agent including DPP-4i. Exacerbation of GD was defined as an increase of antithyroid drug dose by 6 months after oral hypoglycemic agent administration. A total of 80 patients were enrolled and divided into an exacerbation group or a non-exacerbation group. The frequency of DPP-4i administration was significantly higher in the exacerbation group (88%) than that in the non-exacerbation group (31%). In multivariate logistic regression analysis, there was a significant association between DPP-4i administration and GD exacerbation (odds ratio 7.39). The current study suggests that DPP-4i administration is associated with GD exacerbation.

Cytokine storm modulation in COVID-19: a proposed role for vitamin D and DPP-4 inhibitor combination therapy (VIDPP-4i).

A dysregulated immune response characterized by the hyperproduction of several pro-inflammatory cytokines (a.k.a. 'cytokine storm') plays a central role in the pathophysiology of severe coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this Perspective article we discuss the evidence for synergistic anti-inflammatory and immunomodulatory properties exerted by vitamin D and dipeptidyl peptidase-4 (DPP-4) inhibitors, the latter being a class of antihyperglycemic agents used for the treatment of Type 2 diabetes, which have also been reported as immunomodulators. Then, we provide the rationale for investigation of vitamin D and DPP-4 inhibitor combination therapy (VIDPP-4i) as an immunomodulation strategy to ratchet down the virulence of SARS-CoV-2, prevent disease progression and modulate the cytokine storm in COVID-19.

Lay abstract The so-called 'cytokine storm' that drives the hyperproduction of pro-inflammatory mediators, plays a central role in the pathophysiology of severe coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Vitamin D has increasingly been shown to play anti-inflammatory and immunomodulatory properties beyond its role in the regulation of bone homeostasis. Similarly, dipeptidyl peptidase-4 inhibitors (DPP-4i) ­ a class of antihyperglycemic agents used for the treatment of Type 2 diabetes ­ have been reported as immunomodulators regardless of their glucose-lowering properties. We, therefore, discuss the role of vitamin D and DPP-4 inhibitor combination therapy (VIDPP-4i) as a potential immunomodulation strategy to prevent the development and/or halt the progression of the COVID-19-induced cytokine storm, particularly in patients with diabetes and cardiovascular disease.

Begelomab for severe refractory dermatomyositis: A case report.

RATIONALE: Severe refractory idiopathic inflammatory myopathy (IIM) represents a challenge for the clinician. The lack of efficacy of available tools reflects our incomplete insight into the molecular events sustaining the inflammatory tissue damage in these patients. We present the first case of refractory IIM treated with anti-dipeptidyl peptidase-4 (DPP-4)/cluster of differentiation 26 (CD26) monoclonal antibody. PATIENT CONCERNS: A 55-year old man presented with proximal muscle weakness, diffuse erythematous skin lesions which rapidly evolved into ulcerations, dysphagia and dysphonia. DIAGNOSIS: Increased serum creatine kinase levels and histological findings at muscle and skin biopsies were compatible with the diagnosis of dermatomyositis (DM). Several lines of treatment failed to control the disease including steroids, mycophenolate mofetil, tacrolimus, intravenous immunoglobulins and rituximab. Despite therapy, the patient also had recurrent intestinal vasculitis causing bowel perforation. Concurrently, DPP-4/CD26 expression in the patient's skin and skeletal muscle was observed. INTERVENTIONS: The patient was treated with begelomab, a murine immunoglobulin G2b monoclonal antibody against DPP-4/CD26. OUTCOMES: Dysphagia, skin lesions and intestinal vasculitis resolved and the patient experienced a significant improvement of his quality of life. CONCLUSION: Blockade of DPP-4/CD26, which is expressed on T cells and mediates T cell activation and function, is safe and might be effective in patients with refractory DM.

Dipeptidyl peptidase 4 inhibitors and their potential immune modulatory functions.

Dipeptidyl peptidase 4 (DPP4) inhibitors (DPP4is) are oral anti-diabetic drugs (OADs) for the treatment of type 2 diabetes mellitus (T2DM) through inhibiting the degradation of incretin peptides. Numerous investigations have been focused on the effects of DPP4is on glucose homeostasis. However, there are limited evidences demonstrating their Potential modulatory functions in the immune system. DPP4, originally known as the lymphocyte cell surface protein CD26, is widely expressed in many types of immune cells including CD4(+) and CD8(+) T cells, B cells, NK cells, dendritic cells, and macrophages; and regulate the functions of these cells. In addition, DPP4 is capable of modulating plenty of cytokines, chemokines and peptide hormones. Accordingly, DPP4/CD26 is speculated to be involved in various immune/inflammatory diseases and DPP4is may become a new drug class applied in these diseases. This review focuses on the regulatory effects of DPP4is on immune functions and their possible underlying mechanisms. Further clinical studies will be necessitated to fully evaluate the administration of DPP4is in diabetic patients with or without immune diseases.

Preferential Reactivity of Dipeptidyl Peptidase-IV Inhibitor-Associated Bullous Pemphigoid Autoantibodies to the Processed Extracellular Domains of BP180.

Bullous pemphigoid (BP) is a common autoimmune blistering disease in which autoantibodies target the hemidesmosomal components BP180 and/or BP230 in basal keratinocytes. In BP, 80 to 90% of autoantibodies target the juxtamembranous extracellular non-collagenous 16th A (NC16A) domain of BP180. Recently, the administration of dipeptidyl peptidase-IV inhibitors (DPP4i), which are widely used as antihyperglycemic drugs, has been recognized to be a causative factor for BP. DPP4i-associated BP (DPP4i-BP) autoantibodies tend to target epitopes on non-NC16A regions of BP180, and the pathomechanism for the development of the unique autoantibodies remains unknown. To address the characteristics of DPP4i-BP autoantibodies in detail, we performed epitope analysis of 18 DPP4i-BP autoantibodies targeting the non-NC16A domains of BP180 using various domain-specific as well as plasmin-digested polypeptides derived from recombinant BP180. Firstly, Western blotting showed that only one DPP4i-BP serum reacted with the epitopes on the intracellular domain of BP180, and no sera reacted with the C-terminal domain of the molecule. In addition, only 2 DPP4i-BP sera reacted with BP230 as determined by enzyme-linked immunosorbent assay. Thus, DPP4i-BP autoantibodies were found to mainly target the non-NC16A mid-portion of the extracellular domain of BP. Interestingly, Western blotting using plasmin-digested BP180 as a substrate revealed that all of the DPP4i-BP sera reacted more intensively with the 97-kDa processed extracellular domain of BP180, which is known as the LABD97 autoantigen, than full-length BP180 did. All of the DPP4i-BP autoantibodies targeting the LABD97 autoantigen were IgG1, and IgG4 was observed to react with the molecule in only 7 cases (38.9%). In summary, the present study suggests that IgG1-class autoantibodies targeting epitopes on the processed extracellular domain of BP180, i.e., LABD97, are the major autoantibodies in DPP4i-BP.

Drug fever and acute inflammation from hypercytokinemia triggered by dipeptidyl peptidase-4 inhibitor vildagliptin.

A 69-year-old man started taking the dipeptidyl peptidase-4 inhibitor, vildagliptin. One week later, C-reactive protein and plasma immunoglobulin E levels were markedly elevated, and the vildagliptin was stopped. After the patient's laboratory findings were normalized, we decided to restart vildagliptin with the patient's agreement. The next day, he had a high fever, and C-reactive protein and procalcitonin levels were elevated. Although we failed to find a focus of infection, we started antibiotics therapy. Two days later, the high fever had improved, and the C-reactive protein level had decreased. A drug lymphocyte stimulation test showed a positive result for vildagliptin. We examined various kinds of cytokine and infection markers just before and after the treatment with vildagliptin. Finally, we diagnosed the patient with vildagliptin-induced drug fever, probably based on the increase of various inflammatory cytokine levels and the response to this. Taken together, we should be aware of the possibility of vildagliptin inducing drug fever and/or acute inflammation.