Immunosuppressive Therapy and Off-Target Tissue Effects in Organ Transplant Recipients: A Systematic Literature Review

Immunosuppressive therapy is critical for averting graft rejection in organ transplant patients, but its systemic impact on non-targeted tissues is still not well comprehended, which creates major clinical difficulties. This systematic literature review investigates the complex effects of immunosuppression on non-graft tissues while filling gaps in existing understanding and uncovering possible mechanisms responsible for these detrimental outcomes. We performed an extensive review of published research, with particular attention directed toward five principal areas: nanotechnology applications in transplantation, protocols for immunosuppression, therapies based on cells, advancements in technology, and specialized subjects within transplantation. The review indicates that immunosuppressive agents, especially calcineurin inhibitors and mTOR inhibitors, often cause metabolic disturbances, renal dysfunction, and cardiovascular complications, and recent evidence points to epigenetic modifications as a potential underlying mechanism. Importantly, the relationship between immunosuppression and off-target tissue toxicity differs depending on the type of medication, amount administered, and individual patient attributes, which underscores the necessity for tailored treatment approaches. Although progress in nanotechnology and cell-based therapies holds potential for reducing these effects, the transition to clinical application is constrained by inadequate long-term evidence. Our results highlight the necessity of achieving equilibrium between immunosuppressive effectiveness and systemic adverse effects, emphasizing the need for additional investigation into precise delivery mechanisms and monitoring guided by biomarkers. This review consolidates existing evidence to inform clinical practice and guide future investigations into optimizing transplant outcomes while minimizing off-target tissue damage.