International Science Community Association International Research Journal of Biological Sciences 15 1 2026 02 10 Therapeutic monitoring and adverse effects of immunosuppressants in kidney transplant patients: a prospective immunoassay study at Batna University Hospital (Algeria) 1 7 EN Soumaya Boudjemaa 1 University Hospital Centre, Batna, Algeria and Medical faculty, University of Batna, Algeria Said Nadji 2 University Hospital Centre, Constantine, Algeria Chahrazed Rajai 3 University Hospital Centre, Batna, Algeria Hannen Benaldjia 4 University Hospital Centre, Batna, Algeria and Medical faculty, University of Batna, Algeria Berkahoum Alamir 5 National Toxicology Centre, Algeirs, Algeria > Research Paper 2025 11 9 2026 02 10 The preferred course of treatment for end-stage renal failure is kidney transplantation, but its success depends on efficient and balanced immunosuppression. When taken with mycophenolate mofetil, calcineurin inhibitors (tacrolimus, ciclosporin) show significant pharmacokinetic variability and a high risk of toxicity, necessitating careful therapeutic monitoring. This study aims to assess plasma concentrations and side effects related to these compounds' use in kidney transplant recipients. A prospective, descriptive study was realised at the Benflis Touhami University Hospital in Batna (Algeria) between March 2014 and December 2019. It included 246 patients who had received renal transplantation from living donors ; 210 on tacrolimus and 36 on cyclosporine, all receiving mycopenolic acid (MMF) and corticosteroids, the residual (C₀) and post-dose (C₂) concentrations were mesured by electrochemiluminescence. Kidney function and side effects were assessed over a 12-month period. In patients treated with tacrolimus, mean concentrations decreased from 11.8 ng/mL at the beginning of the transplantto 8.5 ng/mL at the end of the first year after transplantation, with stable renal function. In patients treated with cyclosporine, a gradual increase in creatinine and a decrease in glomerular filtration rate were observed. Adverse skin effects (particularly acne) were significantly more frequent with cyclosporine (36.1%, p < 0.001), while neurological disorders (tremors 15.5%) predominated with tacrolimus. Strong correlations were found between plasma concentrations and renal function parameters, particularly for cyclosporine (r = 0.859 between C₀ and creatinine at 12 months). Therapeutic monitoring using immunological methods is a reliable and effective tool for the individualised monitoring of immunosuppressants in renal transplant patients. Tacrolimus has a better renal tolerance profile, while cyclosporine is more often associated with skin effects. These results highlight the importance of personalised pharmacological monitoring in order to optimise post-transplant care. Copyright@ International Science Community Association