Different Patterns of Foxp3 Gene Expression in Pre-and Post-Transplantation Kidney Biopsies and the Effect of Use Mammalian Target of Rapamycin Inhibitors.

BACKGROUND: Trafficking of regulatory T cells (Tregs) modulates the inflammatory response after kidney transplantation (KTx). There is scarce information on whether circulating and intragraft Tregs are similarly affected by immunosuppressive drugs and the type of deceased kidney donor. METHODS: FOXP3 gene expression was measured in the pretransplant kidney biopsies (PIBx) from donors who met extended (ECD) and standard (SCD) criteria donors. In the third month after KTx, the patients were divided according to tacrolimus (Tac) or everolimus (Eve) and the type of kidney they had received. FOXP3 gene expression in the peripheral blood (PB) and kidney biopsies (Bx) was analyzed using real-time polymerase chain reaction. RESULTS: FOXP3 gene expression in the PIBx was higher in ECD kidneys. FOXP3 gene expression in the PB and Bx was greater in Eve- than in Tac-treated patients. However, SCD recipients treated with Eve (SCD/Eve) had higher FOXP3 expression than ECD/Eve. CONCLUSION: Pretransplant kidney biopsies from ECD kidneys had higher FOXP3 gene expression than SCD, and the use of Eve may affect the expression of the FOXP3 gene only in SCD kidneys.

Distinct global DNA methylation and NF-κB expression profile of preimplantation biopsies from ideal and non-ideal kidneys.

BACKGROUND: Epigenetic mechanisms may affect the ideal and non-ideal kidneys selected for transplantation and their inflammatory gene expression profile differently and may contribute to poor clinical outcomes. OBJECTIVE: Study the Global DNA methylation and the expression profiles of the DNA methyltransferases (DNMTs) and nuclear factor kappa B (NF-κB) in preimplantation kidney biopsies from ideal and non-ideal kidneys (expanded criteria donor (ECD) and with KDPI > 85%). METHODS: In a sample consisting of 45 consecutive pre-implantation biopsies, global DNA methylation levels were detected by LINE-1 repeated elements using bisulfite pyrosequencing. DNMT gene expression was assessed by real-time quantitative polymerase chain reaction, and NF-κB protein expression by immunofluorescence. RESULTS: ECD kidneys displayed increased methylation levels in LINE-1, and DNMT1 and DNMT3B expression was upregulated when comparing ECD to standard criteria donor kidneys. Similarly, kidneys with KDPI > 85% exhibited increased LINE-1 methylation and DNMT1 upregulation when compared to a KDPI ≤ 85%. NF-κB protein expression levels were greatly increased in both types of non-ideal kidneys compared to ideal kidneys. Moreover, hypermethylation of LINE-1 was associated with cold ischemia time > 20 h and ECD kidney classification. CONCLUSIONS: This study shows that global DNA hypermethylation and high expression of NF-κB occurred in both types of non-ideal kidneys and were associated with prolonged cold ischemia time. Global DNA methylation can be a useful tool to assess non-ideal kidneys and hence, could be used to expand the pool of kidneys donors.

Kidney complications of parasitic diseases.

Parasitic agents have been known to cause human disease since ancient times and are endemic in tropical and subtropical regions. Complications of parasitic diseases, including kidney involvement, are associated with worse outcomes. Chagas disease, filariasis, leishmaniasis, malaria and schistosomiasis are important parasitic diseases that can damage the kidney. These diseases affect millions of people worldwide, primarily in Africa, Asia and Latin America, and kidney involvement is associated with increased mortality. The most common kidney complications of parasitic diseases are acute kidney injury, glomerulonephritis and tubular dysfunction. The mechanisms that underlie parasitic disease-associated kidney injury include direct parasite damage; immunological phenomena, including immune complex deposition and inflammation; and systemic manifestations such as haemolysis, haemorrhage and rhabdomyolysis. In addition, use of nephrotoxic drugs to treat parasitic infections is associated with acute kidney injury. Early diagnosis of kidney involvement and adequate management is crucial to prevent progression of kidney disease and optimize patient recovery.

Lipoprotein glomerulopathy associated with the Osaka/Kurashiki APOE variant: two cases identified in Latin America.

BACKGROUND: Lipoprotein glomerulopathy (LPG) is a rare autosomal dominant disease caused by mutations in APOE, the gene which encodes apolipoprotein E. LPG mainly affects Asian individuals, however occasional cases have also been described in Americans and Europeans. Herein we report two unrelated Brazilian patients with LPG in whom genetic analyses revealed the APOE-Osaka/Kurashiki variant. CASE PRESENTATION - CASE 1: A 29-year-old Caucasian male sought medical attention with complaints of face swelling and foamy urine for the last 3 months. He denied a family history of kidney disease, consanguinity, or Asian ancestry. His tests showed proteinuria of 12.5 g/24 h, hematuria, serum creatinine 0.94 mg/dL, albumin 2.3 g/dl, total cholesterol 284 mg/dL, LDL 200 mg/dL, triglycerides 175 mg/dL, and negative screening for secondary causes of glomerulopathy. A kidney biopsy revealed intraluminal, laminated deposits of hyaline material in glomerular capillaries consistent with lipoprotein thrombi. These findings were confirmed by electron microscopy, establishing the diagnosis of LPG. His apolipoprotein E serum level was 72 mg/dL and genetic analysis revealed the APOE pathogenic variant c.527G > C, p.Arg176Pro in heterozygosis, known as the Osaka/Kurashiki mutation and positioned nearby the LDL receptor binding site. CASE 2: A 34-year-old Caucasian man sought medical assessment for renal dysfunction and hypertension. He reported intermittent episodes of lower-limb edema for 3 years and a family history of kidney disease, but denied Asian ancestry. Laboratorial tests showed BUN 99 mg/dL, creatinine 10.7 mg/dL, total cholesterol 155 mg/dL, LDL 79 mg/dL, triglycerides 277 mg/dL, albumin 3.1 g/dL, proteinuria 2.7 g/24 h, and negative screening for secondary causes of glomerulopathy. His kidney biopsy was consistent with advanced chronic nephropathy secondary to LPG. A genetic analysis also revealed the Osaka/Kurashiki variant. He was transplanted a year ago, displaying no signs of disease relapse. CONCLUSION: We report two unrelated cases of Brazilian patients with a diagnosis of lipoprotein glomerulopathy whose genetic assessment identified the APOE-Osaka/Kurashiki pathogenic variant, previously only described in eastern Asians. While this is the second report of LPG in Latin America, the identification of two unrelated cases by our medical team raises the possibility that LPG may be less rare in this part of the world than currently thought, and should definitely be considered when nephrotic syndrome is associated with suggestive kidney biopsy findings.

Angiotensin involvement in kidney injury induced by rheumatoid arthritis in rat.

Renal injury induced by rheumatoid arthritis is not clear and may be related to the angiotensin II. We aim to investigate the adjuvant-induced arthritis (AIA) injury in rat kidney, focusing the angiotensin II/AT1 pathway. Male Wistar rats were allocated in to three groups: Control, AIA and AIA plus losartan. The AIA was induced by injection of 100 µL of an emulsion of dissected Mycobacterium tuberculosis (50 mg/mL) on the paw. Treatment with losartan was initiated on the first day of immunization (daily subcutaneous injection, 1 mg/kg). After 60 days post immunization, we evaluated kidney function by plasma creatinine, urea and uric acid levels and creatinine depuration; kidney injury by apoptosis analysis and inflammation markers such as macrophages, transforming growth factor beta (TGF-ß) and inducible nitric oxide synthase (iNOS) expression; oxidative stress by plasma thiobarbituric acid reactive substances (TBARS); renal expression of angiotensin receptors subtype 1 (AT1 ) and 2 (AT2 ) and plasma concentration of angiotensin II. AIA rats showed elevated plasma levels of creatinine, urea, uric acid, TBARS and Ang II and reduced creatinine depuration, and enhanced kidney macrophage number, TGF-ß, caspase-3, iNOS and AT1 /AT2 receptors expression. The losartan reduced plasma creatinine and its clearance, reduced macrophages and the expression of TGF-ß and iNOS in renal tissues, and reduced plasma TBARS. We conclude that AIA causes kidney injury by a physiopathological mechanism that involves AT1  stimulation in renal tissue, elevating the presence of macrophages, the expression of TGF-ß and iNOS, as well the local oxidative stress, which contribute to renal function deterioration.

Therapeutic potential of human induced pluripotent stem cells and renal progenitor cells in experimental chronic kidney disease.

BACKGROUND: Chronic kidney disease (CKD) is a global public health problem. Cell therapy using pluripotent stem cells represents an attractive therapeutic approach for the treatment of CKD. METHODS: We transplanted mitomycin C (MMC)-treated human induced pluripotent stem cells (hiPSCs) and renal progenitor cells (RPCs) into a CKD rat model system. The RPC and hiPSC cells were characterized by immunofluorescence and qRT-PCR. Untreated 5/6 nephrectomized rats were compared to CKD animals receiving the same amount of MMC-treated hiPSCs or RPCs. Renal function, histology, and immunohistochemistry were evaluated 45 days post-surgery. RESULTS: We successfully generated hiPSCs from peripheral blood and differentiated them into RPCs expressing renal progenitor genes (PAX2, WT1, SIX2, and SALL1) and podocyte-related genes (SYNPO, NPHS1). RPCs also exhibited reduced OCT4 expression, confirming the loss of pluripotency. After cell transplantation into CKD rats, the body weight change was significantly increased in both hiPSC and RPC groups, in comparison with the control group. Creatinine clearance (CCr) was preserved only in the hiPSC group. Similarly, the number of macrophages in the kidneys of the hiPSC group reached a statistically significant reduction, when compared to control rats. Both treatments reduced positive staining for the marker α-smooth muscle actin. Histological features showed decreased tubulointerstitial damage (interstitial fibrosis and tubular atrophy) as well as a reduction in glomerulosclerosis in both iPSC and RPC groups. CONCLUSIONS: In conclusion, we describe that both MMC-treated hiPSCs and RPCs exert beneficial effects in attenuating CKD progression. Both cell types were equally efficient to reduce histological damage and weight loss caused by CKD. hiPSCs seem to be more efficient than RPCs, possibly due to a paracrine effect triggered by hiPSCs. These results demonstrate that the use of MMC-treated hiPSCs and RPCs improves clinical and histological CKD parameters, avoided tumor formation, and therefore may be a promising cell therapy strategy for CKD.

Clinical and laboratorial profiles of dengue virus infection in kidney transplant recipients: Report of a single center.

Dengue infection (DI) is the most important arboviral infection in the world. The majority of immunocompetent patients will have asymptomatic or mild infections, but the degree of dengue severity in kidney transplant recipients (KTx) is unknown. In this study, we report the clinical profile and outcomes of 39 dengue cases in KTx. From a total of 1,186 KTx outpatients in follow-up we reviewed clinical and laboratory records of 60 (5%) patients admitted with suspected DI initially screened by NS-1, IgM, and when possible, multiplex nested PCR. The prevalence of DI in KTx was 3% (39/1,118), with symptoms leading to hospital admission being fever, myalgia, malaise, and headache. Laboratory tests showed leucopenia, thrombocytopenia, and liver enzyme elevation. DI was confirmed by positivity of NS-1 (33%), IgM (69%), and/or RT-PCR (59%). Twenty-three patients (59%) had dengue with warning signs, and 15% had severe dengue, 2 of them with a fatal course. Acute graft dysfunction occurred in 59% (mean nadir serum creatinine: 2.9 ± 2.6mg/dL), 4 of them requiring dialysis. CMV coinfection diagnosed in 19% of the cases and patients was associated with worse clinical presentation. Our results suggest that KTx with DI presented initial physical and laboratorial profile similar to the general population. However, DI in KTx seems to have a higher risk for graft dysfunction, severe dengue, and death. Because CMV coinfection aggravates the DI clinical presentation and recovery, it must be evaluated in all cases.

Induced Pluripotent Stem Cells Reduce Progression of Experimental Chronic Kidney Disease but Develop Wilms' Tumors.

The therapeutic effect of induced pluripotent stem cells (iPSs) on the progression of chronic kidney disease (CKD) has not yet been demonstrated. In this study, we sought to assess whether treatment with iPSs retards progression of CKD when compared with bone marrow mesenchymal stem cells (BMSCs). Untreated 5/6 nephrectomized rats were compared with CKD animals receiving BMSCs or iPSs. Renal function, histology, immunohistochemistry, and gene expression were studied. Implanted iPSs were tracked by the SRY gene expression analysis. Both treatments minimized elevation in serum creatinine, significantly improved clearance, and slowed down progression of disease. The proteinuria was reduced only in the iPS group. Both treatments reduced glomerulosclerosis, iPSs decreased macrophage infiltration, and TGF-ß was reduced in kidneys from the BMSC group. Both types of treatments increased VEGF gene expression, TGF-ß was upregulated only in the iPS group, and IL-10 had low expression in both groups. The SRY gene was found in 5/8 rats treated with iPSs. These 5 animals presented tumors with histology and cells highly staining positive for PCNA and Wilms' tumor protein antibody characteristics of Wilms' tumor. These results suggest that iPSs may be efficient to retard progression of CKD but carry the risk of Wilms' tumor development.

Validation of an Experimental Model to Study Less Severe Chronic Renal Failure.

PURPOSE: The 5/6 nephrectomy, mimics the stages of human chronic renal failure (CRF), but the procedure causes severe renal functional and morphological damage that could interfere with the evaluation of therapies for slowing the progression of the disease. This study summarizes the results of renal function, histology, and immunohistochemical findings in rats undergoing a 2/3 nephrectomy. METHODS: The rats were distributed in groups according to the type of nephrectomy: CRF5/6: induced by a 5/6 renal mass reduction and CRF2/3: less severe CRF. The body weight and blood pressure were monitored, and the serum creatinine (SCr), creatinine clearance (CCr), urine osmolality, and 24-h proteinuria (PT24h) were measured. CRF progression was evaluated by the rate of decline of CCr (RCCr). Histology and immunohistochemistry were performed in the remnant kidneys. Statistical analysis was done by unpaired t-test, and a P-value < 0.05 was taken as a statistical significance. RESULTS: Compared to the CRF5/6 group, the CRF2/3 model had a lower SCr, PT24h, CCr, and variations of the SCr from baseline. The disease progression was also significantly slower. The renal histopathological findings revealed fewer chronic lesions in rats with CRF2/3. Similarly, we observed less macrophage accumulation as well as lower proliferative activity and expression of fibronectin and a-smooth muscle-actin in the CRF2/3 model. CONCLUSIONS: The CRF2/3 model presented with a pattern of less severe CRF, functionally and morphologically, compared to the classical CRF5/6 model, and the CRF2/3 model may be useful for evaluating therapeutic interventions that target the early stages of CRF.

Fatores sociodemográficos e clínicos associados à qualidade de vida relacionada à saúde dos pacientes transplantados renais / Demographic and clinical factors associated with health-related quality of life of kidney-transplanted patients / Factores demográficos y clínicos asociados a la calidad de vida relacionada con la salud de los pacientes trasplantados renales

Objetivo: identificar os fatores sociodemográficos e clínicos dos pacientes com doença renal crônica (DRC) que realizaram transplante renal e correlacioná-los à qualidade de vida. Método: estudo descritivo e transversal realizado com 49 pacientes transplantados renais em acompanhamento ambulatorial. A coleta de dados foi realizada por meio de entrevista e o questionário WHOQOL-BREF e analisados pelo programa Epi Info™ 7. O projeto de pesquisa foi aprovado pelo Comitê de Ética em Pesquisa, CAAE nº 252214. Resultados: 77,55% dos pacientes eram homens, com idade média de 46,5±14,3 anos, 95,92% eram alfabetizados e 63,26% moravam com companheiros. Os principais motivos da DRC foram: hipertensão arterial (28,57%); e nefrite (20,41%). Na qualidade de vida, os domínios mais afetados foram o físico e o ambiental. Conclusão: o perfil sociodemográfico caracterizou-se por homems, em idade produtiva, brancos, alfabetizados e com companheiros. Os domínios da qualidade de vida mais afetados foram o físico e o ambiental.(AU)

Objective: to identify the demographic and clinical factors of patients with chronic kidney disease (CKD) who underwent kidney transplantation, and correlate them to the quality of life. Method: descriptive, crosssectional study conducted with 49 kidney-transplanted patients attending outpatient follow-up appointments. The data were collected by means of interviews and the questionnaire WHOQOL-BREF, and analyzed using the Epi Info™ 7 software. The research project was approved by the Research Ethics Committee, CAAE No. 252214. Results: 77.55% of the patients were men with an average age of 46.5±14.3 years, 95.92% were literate, and 63.26% lived with a partner. The main reasons of CKD were: arterial hypertension (28.57%); and nephritis (20.41%). Regarding quality of life, the most affected domains were the physical and the environment. Conclusion: the demographic profile was characterized by men, of productive age, white, literates, and with partners. The most affected domains of quality of life were the physical and the environment.(AU)

Objetivo: identificar los factores demográficos y clínicos de los pacientes con enfermedad renal crónica (ERC) que realizaron trasplante renal y correlacionarlos con la calidad de vida. Método: estudio descriptivo y transversal realizado con 49 recipientes trasplantados renales en seguimiento ambulatorio. Los datos fueron recogidos mediante entrevistas y con el cuestionario WHOQOL-BREF y analizados usando el software Epi Info™ 7. El proyecto de investigación fue aprobado por el Comité de Ética en Investigación, CAAE N° 252214. Resultados: el 77,55% de los pacientes eran hombres; con edad promedio de 46,5±14,3 años, el 95.92% era alfabetizado y el 63,26% vivía con compañero. Las principales razones de la ERC fueron: hipertensión arterial (28,57%); y nefritis (20,41%). Con respecto a la calidad de vida, los dominios más afectados fueron el físico y el ambiente. Conclusión: el perfil demográfico estaba constituido por hombres, en edad productiva, blancos, alfabetizados y con compañeros. Los dominios de la calidad de vida más afectados fueron el físico y el ambiente.(AU)

Comparative effects of mesenchymal stem cell therapy in distinct stages of chronic renal failure.

BACKGROUND: The therapeutic potential of adult stem cells in the treatment of chronic diseases is becoming increasingly evident. In the present study, we sought to assess whether treatment with mesenchymal stem cells (MSCs) efficiently retards progression of chronic renal failure (CRF) when administered to experimental models of less severe CRF. METHODS: We used two renal mass reduction models to simulate different stages of CRF (5/6 or 2/3 mass renal reduction). Renal functional parameters measured were serum creatinine (SCr), creatinine clearance (CCr), rate of decline in CCr (RCCr), and 24-h proteinuria (PT24h). We also evaluated renal morphology by histology and immunohistochemistry. MSCs were obtained from bone marrow aspirates and injected into the renal parenchyma of the remnant kidneys of both groups of rats with CRF (MSC5/6 or MSC2/3). RESULTS: Animals from groups MSC5/6 and CRF2/3 seemed to benefit from MSC therapy because they showed significantly reduction in SCr and PT24h, increase in CCr and slowed the RCCr after 90 days. Treatment reduced glomerulosclerosis but significant improvement did occur in the tubulointerstitial compartment with much less fibrosis and atrophy. MSC therapy reduced inflammation by decreasing macrophage accumulation proliferative activity (PCNA-positive cells) and fibrosis (α-SM-actin). Comparisons of renal functional and morphological parameters responses between the two groups showed that rats MSC2/3 were more responsive to MSC therapy than MSC5/6. CONCLUSION: This study showed that MSC therapy is efficient to retard CRF progression and might be more effective when administered during less severe stages of CRF.

Supplementation with omega-3 polyunsaturated fatty acids and experimental tacrolimus-induced nephrotoxicity.

OBJECTIVES: Calcineurin inhibitors are effective immunosuppressive agents, but associated adverse effects such as nephrotoxicity may limit efficacy. Dietary fish oil may minimize nephrotoxicity caused by long-term use of calcineurin inhibitors. The purpose of the present study was to evaluate the effects of omega-3 fatty acids on calcineurin inhibitor nephrotoxicity in rats that had normal kidney function or chronic kidney failure. MATERIALS AND METHODS: Rats that had normal kidney function or chronic renal failure that was induced by mass reduction surgery were treated with tacrolimus without or with fish oil, fish oil alone, or olive oil. Kidney function and histology were evaluated after 14 days. RESULTS: Mean body weight loss, serum creatinine, change in serum creatinine, and rate of decrease in creatinine clearance were greater in normal rats that received than did not receive tacrolimus. Tacrolimus nephrotoxicity was greater in rats that had chronic renal failure than normal kidney function, but the mean change in serum creatinine was significantly lower in rats with chronic renal failure that were treated with tacrolimus and fish oil than tacrolimus alone. Fish oil supplementation was associated with fewer abnormal histopathologic lesions in the kidneys of tacrolimustreated rats that had normal kidney function or chronic renal failure (not signifant). CONCLUSIONS: Fish oil may be protective against the development of kidney dysfunction and histopathologic changes in rats treated with tacrolimus.

Effects of polyunsaturated fatty acids (PUFAs) in the treatment of experimental chronic renal failure.

PURPOSE: A diet with polyunsaturated fatty acid (PUFA) supplementation has been reported to reduce renal and cardiac diseases. This study sought to elucidate whether PUFAs derived from plant or marine oils could have beneficial effects on the progression of experimental chronic renal failure (CRF). METHODS: Experimental CRF was achieved by a 5/6 nephrectomy model. Male Wistar rats were divided into groups and given daily supplements of fish oil (group FO), flaxseed oil (group FXO), or soybean oil (control-group SO) for 30 days. Serum creatinine (sCr), 24-h proteinuria, total cholesterol, triglycerides, and creatinine clearance (CLcr) were measured at day 0 and 30 days after surgery when the rats were euthanized for histological analysis of the remnant kidney. RESULTS: After 30 days, we observed lower levels of sCr in the groups supplemented with PUFA when compared with the control group (FO: 0.92 ± 0.13; FXO: 1.06 ± 0.28; SO: 1.32 ± 0.47 mg/dL) and significantly slower variations of sCr (ΔsCr) in the groups treated with PUFAs (FO = 0.35 ± 0.16; FXO = 0.47 ± 0.31; OS = 0.72 ± 0.43; mg/dL, P = 0.041). Similarly, the CLcr of both of the groups that received PUFAs was significantly slower than the rats in the control group (FO: 0.45 ± 0.15; FXO: 0.60 ± 0.09; SO: 0.28 ± 0.06 mL/min/day; P = 0.01). The rats that received PUFA supplements also presented significantly less histological lesions compared with the control group. CONCLUSIONS: These results suggest a beneficial effect of dietary supplementation with flaxseed or fish oil in rats with CRF.

Effect of cyclosporine a on glucose interstitial concentration in renal cortex and medulla from rats.

AIM: To standardize microdialysis in rat kidneys and address cyclosporine A (CsA) effects on renal cortex and medulla interstitial glucose. METHODS: Munich-Wistar rats were treated with vehicle or CsA (15 mg/kg/day) for 3 weeks. Glucose was assessed by spectrophotometry in dialysate samples from cortex, medulla and arterial plasma. Plasma insulin was measured by radioimmunoassay. Renal blood flow (RBF) was measured by Doppler ultrasound. Creatinine and urea were measured by spectrophotometry. RESULTS: CsA significantly increased the plasma levels of urea and creatinine (1.5 +/- 0.20 vs. 0.73 +/- 0.03 mg/dl in controls, p < 0.05). Medullary glucose in control was 44% lower than arterial glucose (56 +/- 6 vs. 101 +/- 8 mg/dl, p < 0.05). At the same time, CsA increased arterial (163 +/- 35 vs. 101 +/- 8 mg/dl in controls, p < 0.05) and medullary interstitial glucose (100 +/- 18 vs. 56 +/- 6 mg/dl in controls, p < 0.05), but did not affect cortical glucose (114 +/- 21 vs. 90 +/- 11 mg/dl in controls). These changes occurred in the presence of a decreased plasma insulin level (2.7 +/- 0.2 vs. 9.3 +/- 0.4 microU/ml in controls, p < 0.05). The increment in medullary glucose in CsA group occurred despite a reduction in RBF (4.6 +/- 0.8 vs. 6.5 +/- 1.0 ml/min/kidney in controls, p < 0.05). CONCLUSIONS: Microdialysis was an adequate tool to investigate in vivo regulation of renal glucose metabolism. Renal glucose uptake was dependent on medullary cells and CsA treatment induced diabetogenic effects on renal medulla in situ.

Hiper-homocisteinemia em pacientes submetidos a transplante renal / Hyperhomocysteinemia in renal transplant recipients

A doença vascular do transplante apresenta fisiopatogenia semelhante a do processo de envelhecimento vascular e da aterosclerose. Consequentemente, genes cujas enzimas estão ligadas a esse processo, como a enzima metilenotetrahidrofolato redutase (MTHFR) que participa do metabolismo da homocisteína e formação da placa aterosclerótica, passaram a ser valorizados no processo etiopatológico da disfunção crônica do transplante (DCTx). Neste estudo, as frequências dos polimorfismo MTHFR (C677T e A1298C) e os níveis plasmáticos de homocisteína (Hcy) foram avaliados em 45 pacientes submetidos a transplante renal no mínimo há 12 meses, 21 com DCTx e 24 com função renal normal (FN). A quantificação da hemocisteína foi realizada por cromatografia líquida/espectrometria de massas sequencial (LC-MS/MS) e a investigação dos polimorfismo MTHFR pela análise de comprimento de fragmentos de restrição (PCR-RFLP). O genótipo 677CT/1298AC foi associado ao nível moderado de Hcy em pacientes com DCTx