Introduction: Non-adherence to immunosuppressive treatment after renal transplantation is a major cause of graft failure. It is unknown whether the histology in protocol renal biopsies in non-adherent renal transplant patients differs from that adherent patients. 
Among strategies to evaluate adherence to immunosuppression are adherence tests. The Basel Assessment of Adherence with Immunosuppressive Medication Scale-BAASIS® was used, validated in spanish language for use in kidney transplant patients. Cardoso BD reported non-adherence in 72% of brazilian kidney transplants. 
Einecke G mentions that ah Banff scores remain less than 1 until approximately 500 days post-transplant.
Method: Observational, analytical, transversal and prospective study from January 2018 to February 2023. Were included all G5 KDIGO chronic kidney patients who were transplanted at Central Military Hospital, Mexico. When patients were 3 years post-transplant, they underwent renal biopsy protocol, which was histologically analyzed using the Banff score and at the same time the Scale-BAASIS® was applied. The Kolmogorov-Smirnov test was performed to determine the normality of the variables, analytical statistics were performed with Xi²and Mann-Whitney tests; p< 0.05 was statistically significant.
Results: Were included 200 kidney transplant recipients. Using Scale-BAASIS®, non-compliance prevalence 3 years post-transplant was 40.5%. There weren´t subtherapeutic tacrolimus levels.

Subclinical humoral rejection (acute or chronic) was diagnosed in 35% of the patients, microvascular inflammation in 32.7%. 

There wasn´t correlation between microvascular inflammation or calcineurinic toxicity with the dichotomous variable of adherence, but when performing a sub-analysis comparing adherence vs. BAASIS score ≥2, these were the Banff results: g=0.179, ptc=.479, g+ptc=0.208, c4d=0.370, i=0.524, t=0.606, IFTA =0.281, aah=0.062, ah=0.022, v=0.641, cv=0.629. 
This finding was associated with a higher score on test´s questions 3 and 4, which shows that non-adherent patients overcompensate for non-ingested doses of immunosuppression, increasing toxicity from calcineurin inhibitors.
Discussion:  Our results are similar to reported in 2019 by Al-Sheyyab A et al, where 39% were non-compliance and there weren´t differences in the presence of antibody-mediated rejection between both groups, but his adherent group had a higher IFTA. Lerut E et al concluded that non-adherent patients have greater interstitial infiltrate (p=0.0100), interstitial fibrosis (p=0.0277) and tubular atrophy (p=0.0197); similar results found by Cardoso, BD: non-adherent group had higher IFTA (95% CI 15.16-20.53) (p = 0.015).
Conclusion: Non-compliance rate in our transplant population was 40.5%. We find a statistically significant association between treatment adherence measured by BAASIS© scale and hyalinosis lesions determined in protocol renal biopsies.