Should post kidney transplantation hyperlipidemia considered a risk factor for graft function?

BACKGROUND

Hyperlipidemia is a common problem after kidney transplantation.

OBJECTIVE

To uncover the real impact of post kidney transplantation hyperlipidemia on graft function and survival, and to determine whether it is just a biochemical phenomenon after using immunosuppressant or a part of disease pathology.

METHODS

330 kidney transplants were managed in Sina Hospital Kidney Transplantation Unit affiliated to Tehran University of Medical Sciences, Tehran, Iran from September 1994 till February 2010. The demographic characteristics of the patients, causes of chronic kidney diseases, history of pretransplantation dialysis, pretransplantation comorbidities (e.g., hypertension, diabetes mellitus [DM], hyperlipidemia and coronary artery disease), rejection episodes, status of infection with cytomegalous virus [CMV], post-transplantation DM, hyperlipidemia, ischemic heart disease [IHD], and graft and patient survival were recorded. A serum creatinine level >2 mg/dL was considered as "graft deterioration," and return to dialysis as "graft loss." According to the presence or absence of post kidney transplantation hypercholesterolemia (>200 mg/dL) or hypertriglyceridemia (>200 mg/dL), the patients were classified into "hyperlipidemic" or "non-hyperlipidemic." The presence of clinical or paraclinical coronary artery disease was also determined in both groups.

RESULTS

The incidence of hyperlipidemia elevated from 8% to 50% before and after transplantation. 2.7% developed clinical IHD. 13% of hyperlipidemics and 22% of non-hyperlipidemics developed graft deterioration. Among hyperlipidemics with deteriorated grafts 40% had premorbid diseases, 68% had CMV infection and 82% had hypertension. Only 22% had previous acute rejection and 27% received deceased kidney transplant.

CONCLUSIONS

post kidney transplantation hyperlipidemia is just an associated phenomenon secondary to the use of immunosuppressant medications, which have no obvious impact on renal graft function and can be easily controlled by instituting dietary modifications and use of modern antilipid medications. Post kidney transplantation CMV infection and hypertension are considered as the main threatening risk for renal graft-even more dangerous than acute or chronic rejections.

Microchimerism and renal transplantation: doubt still persists

OBJECTIVE

We sought to study microchimerism in a group of kidney transplant recipients.

MATERIALS AND METHODS

In this study, the peripheral blood microchimerism (PBM) after renal transplantation was retrospectively evaluated in 32 male-to-female recipients of living unrelated or cadaveric donor renal transplants. Using a nested polymerase chain reaction (PCR) amplification specific for SRY region of the Y chromosome, microchimerism was detected with a sensitivity of 1:1,000,000. Recipients were compared according to the presence of PBM, acute and chronic rejection episodes, type of allotransplant, recipient and donor age at transplantation, previous male labor or blood transfusion, allograft function (serum creatinine level), and body mass index.

RESULTS

Among 32 recipients, 7 (21.9%) were positive for PBM upon multiple testing at various posttransplant times. All microchimeric recipients had received kidneys from living unrelated donors. No significant difference was observed with regard to other parameters. In addition the acute rejection rate in the microchimeric group was 3 (42%) versus 4 (16%) in the nonmicrochimeric recipients (not significant).

CONCLUSION

Our results suggested better establishment of microchimerism after living donor kidney transplantation. However, doubt persists concerning the true effect of microchimerism after renal transplantation. It seems that microchimerism alone has no major protective role upon renal allograft survival.

Does donor nephron mass have any impact on graft survival?

OBJECTIVES

Functioning nephron mass namely, the number of nephrons in the grafted kidney, is one of the nonimmunologic factors that may have some impact on long-term graft survival. The aim of this study was to assess the impact of donor nephron mass on graft outcome in the recipient.

MATERIALS AND METHODS

From 1989 to 2005, 1000 renal transplants were performed at our center. The 217 studied cases were followed for an average of 8 years. All patients received grafts from living donors. The weight of the grafted kidney (donor nephron mass) as well as the recipient's body mass index (BMI) were measured at the time of operation. Nephron mass index (NMI) was defined as the ratio of donor nephron mass to recipient BMI. Associations between variables were tested by logistic regression and Pearson correlation using the SAS system and S-plus statistical software. To evaluate graft function, we determined serum creatinine values, acute rejection episodes and chronic nephropathy.

RESULTS

Mean NMI was 8.07 +/- 0.2 and mean creatinine level was 1.43 +/- 0.4 mg/dL. There were 32 cases (14.7%) of acute rejection, who were managed successfully with antithymocyte globulin (ATG) in 28 cases. Four patients lost their grafts. There were 15 cases (7%) of graft loss due to chronic rejection. Using Pearson correlation, we observed no association between NMI and mean serum creatinine level. Logistic regression showed a significant relation between NMI and acute rejection (P<.05) with an odds ratio of 2.0. There was no significant correlation between NMI and chronic rejection.

CONCLUSIONS

The lower the NMI, the greater the short-term graft loss. However, in the long term, no significant correlation was found between graft survival and NMI. Also, mean creatinine level was not significantly different among patients regardless of NMI.

Pelvic nerve neuropathy after kidney transplantation

OBJECTIVES

We examined the relation of various age, gender, diabetes, hypertension, and graft function with the prevalence of femoral and lateral cutaneous nerves sensory and/or motor disturbances after kidney transplantation.

MATERIALS AND METHODS

Among 129 patients who underwent kidney transplantation from April 2001 to March 2002. We excluded, 10 due to preoperative sensory disturbances. We evaluated the prevalence of sensory and/or motor disturbances preoperatively by physical examination and postoperatively by both physical and electromyography examinations. The clinical findings were correlated with the following risk factors: age, gender, preoperative dialysis duration, background diseases. (e.g., diabetes, hypertension), graft weight, nephron mass index, operative and retraction time, and rejection episodes.

RESULTS

At 1 to 9 days postoperatively, 31 ng (26%) patients, suffered neuropathy of the lateral cutaneous nerve and 4 (3.3%), femoral neuropathy. No meaningful relation was detected between the incidence of neuropathy and these risk factors. The probability of neuropathy was greater among diabetics, hypertensives, women, and those with graft rejection episodes. All of these complaints were temporary.

CONCLUSIONS

Post-kidney transplant femoral and/or lateral cutaneous nerve neuropathy is a prevalent complication particularly in diabetic, hypertensive, and female patients. Neuropathy is also more evident after graft rejection.

Does Renal Transplantation Improve Erectile Dysfunction in Hemodialysed Patients? What is the Role of Associated Factors?

OBJECTIVE

To assess the effect of successful renal transplantation on improvement of erectile function in hemodialysis (HD) patients and the relationship between the degree of patient response and other factors.

MATERIALS AND METHODS

From September 2002 to November 2005, erectile function of 64 patients on HD for at least 6 months was evaluated pretransplantation and 6 months posttransplantation by International Index of Erectile Function, version 5 (IIEF-5). Sixty four age-matched persons without renal impairment were enrolled as control group to compare erectile dysfunction (ED) prevalence with the HD group. We evaluated duration of HD, age, and site of arterial anastomosis. In an attempt to find predictors of improvement of ED, after kidney transplantation, we performed linear regression analysis with a backward method.

RESULTS

The prevalence of ED in HD patients was 87.5%. Although there were some differences in the prevalence of ED between patients older versus younger than 50 years, the difference was not statistically significant. There was no relationship between the duration of dialysis and the severity of ED in HD group. Compared to the pretransplant IIEF-5 score (13.59), there was significant improvement (19.16). In an attempt to find predictors of ED improvement, we used a linear regression analysis with backward method. Pretransplant IIEF-5 score, age at the time of transplant, and anastomosis to the common iliac artery showed significant associations with improvement, but the duration of dialysis and anastomosis to internal iliac or external iliac artery did not.

CONCLUSION

The incidence of ED among hemodialyzed patients is high. Kidney transplantation is the key treatment for this complaint. ED has a major negative impact on the quality of life and family relations. Its treatment is associated with improvement of psychogenic factors. ED is a sensitive topic and many patients will not spontaneously discuss it with their physician, so better to include potency evaluation in posttransplantation list evaluations.

The relationship between lipid profile and erectile dysfunction

The objective of this study is to investigate the relation between serum lipids (cholesterol, LDL, HDL, triglyceride (TG)) and erectile dysfunction (ED). The experimental methods involved comparison of 100 patients with organic ED (mean age of 43.59+/-10.51 y), with 100 healthy individuals (mean age of 43.72+/-9.76 y) regarding their lipid profile from January 2000 to June 2003 (cholesterol, TG, HDL, LDL). The results showed that there was a significant difference between mean plasma cholesterol and LDL levels in the individuals suffering from ED and the control group (P=0.04 and 0.02, respectively). The TG and HDL mean plasma level differences were not significant (P=0.583 and 0.299, respectively). Odds ratios for high plasma cholesterol level (>240 mg/dl) and high plasma LDL level (>160 mg/dl) were 1.74 and 1.97. The R2 was 0.04 for both cholesterol and LDL. Applying linear regression, the coefficient for cholesterol and LDL reduced the International Index of Erectile Function questionnaire scores by -0.036 and -0.035. In conclusion, this study, the correlation of cholesterol and LDL levels with ED strongly supports the role of hyperlipidemia treatment in both the prevention and management of ED.