The influence of serial 50 μL microsampling on rats administered azathioprine, the immunosuppressive drug

Yoichi Tanaka; Kazuaki Takahashi; Norimichi Hattori; Hideaki Yokoyama; Koki Yamaguchi; Yusuke Shibui; Sayaka Kawaguchi; Taishi Shimazaki; Keiko Nakai; Hiroyuki Kusuhara; Yoshiro Saito

doi:10.1016/j.toxrep.2023.02.016

The influence of serial 50 μL microsampling on rats administered azathioprine, the immunosuppressive drug

Toxicol Rep. 2023 Mar 1:10:334-340. doi: 10.1016/j.toxrep.2023.02.016. eCollection 2023.

Authors

Affiliations

¹ Division of Medicinal Safety Science, National Institute of Health Sciences, 3-25-26, Tonomachi, Kawasaki-ku, Kasasaki-shi, Kanagawa, Japan.
² LSIM Safety Institute Corporation., 14-1 Sunayama, Kamisu-shi, Ibaraki, Japan.
³ Ajinomoto Fine-Techno Co., Inc., 1-1, Suzuki-cho, Kawasaki-ku, Kwasaki-shi, Kanagawa, Japan.
⁴ Japan Tobacco Inc., 1-13-2, Fukuura, Kanazawa-ku, Yokohama-shi, Kanagawa, Japan.
⁵ Laboratory of Molecular Pharmacokinetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.

Abstract

According to the ICH S3A Q&A, microsampling is applicable to pharmaceutical drugs and toxicological analysis. Few studies have reported the effect of microsampling on the toxicity of immunotoxicological drugs. The aim of this multicenter study was to evaluate the toxicological effects of serial microsampling on rats treated with azathioprine as a model drug with immunotoxic effects. Fifty microliters of blood were collected from the jugular vein of Sprague-Dawley rats at six time points from day 1 to 2 and 7 time points from day 27 to 28. The study was performed at three organizations independently. The microsampling effect on clinical signs, body weights, food consumption, hematological parameters, biochemical parameters, urinary parameters, organ weights, and tissue pathology was evaluated. Azathioprine-induced changes were observed in certain hematological and biochemical parameters and thymus weight and pathology. Microsampling produced minimal or no effects on almost all parameters; however, at 2 organizations, azathioprine-induced changes were apparently masked for two leukocytic, one coagulation, and two biochemical parameters. In conclusion, azathioprine toxicity could be assessed appropriately as overall profiles even with blood microsampling. However, microsampling may influence azathioprine-induced changes in certain parameters, especially leukocytic parameters, and its usage should be carefully considered.

Keywords: A/G, albumin/globulin; ALP, alkaline phosphatase; ALT, alanine transaminase; APTT, activated partial thromboplastin time; AST, aspartate transaminase; Azathioprine; BUN, blood urea nitrogen; CPK, creatine phosphokinase; Ca, calcium; Cl, chloride; Cre, creatinine; GLDH, glutamate dehydrogenase; Hematological parameter; ICH, International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use; Jugular vein; K, potassium; LDH, lactate dehydrogenase; MCH, mean corpuscular hemoglobin; MCHC, mean corpuscular hemoglobin concentration; MCV, mean corpuscular volume; Microsampling; Na, sodium; P, inorganic phosphorus; PT, prothrombin time; RBC, red blood cell; Rat; TK, toxicokinetics; Toxicokinetics; WBC, leukocyte/white blood cell; γGT, γ-glutamyltranspeptidase.