Pediatric kidney dimensions and risk of persistent albuminuria in Mexican adolescents

In Mexico, chronic kidney disease of unknown origin is highly prevalent. Screening studies in adolescents have shown persistent microalbuminuria (pACR), adaptive podocytopathy and decreased kidney volume (KV). Here, we sought to develop normality tables of kidney dimensions by ultrasound in the Mexican state of Aguascalientes pediatric population (0 to 18y) and evaluate the relationship between the KV and pACR among the region's adolescents in a cross-sectional study. Kidney length (KL) and KV were determined by ultrasound. Our findings were compared with those in international literature of different populations where tables and graphs of normal kidney dimensions by ultrasound were reported. We compared organ dimensions in individuals above the age of 11 without albuminuria with those in patients with pACR recruited through screening studies in adolescents in Aguascalientes. This included 1068 individuals to construct percentile tables and graphs of the KL. Kidney dimensions were significantly lower when compared with all international comparisons. From a total 14,805 screen individuals, we compared 218 adolescents with pACR and 377 individuals without significant albuminuria. The Total KV adjusted to body surface (TKVBS) was significantly associated with pACR (odds ratio 1.03, 95% confidence interval 1.02-1.03). The upper quartile of TKVBS was highly associated with pACR (7.57, 4.13-13.87), hypertension (2.53, 1.66-3.86), and hyperfiltration (26 vs 11.5%). Thus, TKVBS is directly associated with pACR while greater KV, arterial hypertension, and hyperfiltration in patients with pACR suggest that the increase in volume is secondary to kidney hypertrophy. Additionally, the adaptative podocytopathy with low fibrosis seen on kidney biopsy which was performed in a subset of patients, and the smaller kidney dimensions in our population point to prenatal oligonephronia as the primary cause of the detected kidney disease.

Chronic Kidney Disease Risk Profile in Renal Donors in Aguascalientes, Mexico: A Retrospective Cohort Study

BACKGROUND

In the last decade, kidney donation has been recognized as a risk factor for end-stage renal disease (ESRD). ESRD risk calculators have been recently perfected in North American populations. In Mexico, the rates of overweight, obesity, and diabetes mellitus (DM) are among the highest worldwide; nevertheless, most kidney transplants are obtained from living donors. This study aims to describe the risk profile for chronic kidney disease (CKD) development in kidney donors in a highly active transplant center in Central Mexico.

METHODS

We conducted a retrospective, observational, descriptive cohort study of kidney donors followed at the Hospital Centenario Miguel Hidalgo (CHMH). We used the pretransplant CKD risk calculator at 15 years and over a lifetime (www.transplantmodels.com/esrdrisk). Aside from the calculator of kidney failure risk, we also used the calculator for postdonation CKD risk (www.transplantmodels.com/donesrd/). Factors associated with a glomerular filtration rate (GFR) <60 mL/min were evaluated by univariate and multivariate analysis.

RESULTS

The study included 543 donors. The average follow-up period was 1.7 years (±2.7) with a median of 0.7 years (interquartile range, 0.2-2.1). The average predicted risk for ESRD development at 15 years was 0.08% (±0.1); 25.6% had a risk >0.1%, and only 1 patient had a risk >1%. The lifetime ESRD risk was 0.62% (±0.5); 15% had a risk >1%, and the greatest risk was 3.5%. The median of patients at risk of developing postdonation ESRD was 1 in 10,000 donors (0.6-1.5) at 5 years, 5.7 in 10,000 donors (3.5-8.8) at 10 years, 15 in 10,000 donors (9.1-23.2) at 15 years, and 31 in 10,000 donors (18.9-47.7) at 20 years. During the follow-up period, 52 patients developed a GFR of <60 mL/min. Both risk estimation formulas were significantly associated with a GFR of <60 mL/min. Among the individual factors, the GFR (hazard ratio 0.96, 95% confidence interval 0.94-0.97, P < .001) and the urinary albumin to creatinine ratio (hazard ratio 1.009, 95% confidence interval 1.005-1.01, P < .001) remained statistically significant.

CONCLUSION

The risk of ESRD in kidney donors in Aguascalientes, Mexico, is similar to that described in the United States. Risk calculators are an indispensable decision-making tool to better understand kidney donors in our milieu.

Changes in the commercial brand of tacrolimus lead to subtherapeutic trough levels and acute rejection in renal transplant recipients

BACKGROUND

The vigilance of tacrolimus (TAC) trough levels is an essential part of renal transplant follow up. Reduced TAC trough levels and high variability are related to adverse outcomes. The aim of this study was to evaluate the impact of brand changes on tacrolimus (TAC) subtherapeutic (SubT) trough levels, acute rejection (AR), and kidney function.

METHODS

This is a prospective, observational cohort study of renal transplant recipients, between January 2016 and October 2018. Tacrolimus trough levels and brand used by the patient were both registered at every consult. Tacrolimus values ≤3.5 ng/mL were considered SubT.

RESULTS

445 patients were included. The median number of TAC brand changes was 2 (IQR, 1-4). Patients were grouped according to the number of brand changes: Group 1 = 0 (n = 107), Group 2 = 1-4 (n = 236), and Group 3 = ≥5 (n = 102). Patients with the greatest number of brand changes had a greater proportion and number of SubT TAC trough levels (Group 1 = 36.4%, average 0.53; Group 2 = 39.8%, average 0.65, Group 3 = 59.8%, average 1.17, P < .001) and AR (Group 1 = 0.9%, Group 2 = 11%, Group 3 = 14.7%, P < .001). On multivariate analysis, SubT levels and the number of brand changes were related to AR.

CONCLUSIONS

In Mexico, changes in TAC brand are associated with an elevated frequency of SubT levels. Brand changes and SubT levels are independently associated with acute rejection. The supply policies on TAC brands in Mexico require revision to avoid changing brands as much as possible.

[Renal transplantation program at the Centenario Hospital Miguel Hidalgo in Aguascalientes, Mexico]

INTRODUCTION

Miguel Hidalgo Hospital in Aguascalientes is dependent from the Federal Secretary of Health and operates in integrity with State health system in Aguascalientes. It capacity is based on 132 censored beds and 71 no censored beds. Is considered a specialty hospital in the region of Bajío. Renal transplant program activity was initiated in 1990 and gives care for adult and pediatric population.

MATERIAL AND METHODS

Retrospective, comparative and longitudinal study to describe and analyze our experience. Data base and clinical charts of renal transplant recipients were reviewed. Age, gender, date of transplant, etiology of renal disease, type of donor, HLA compatibility and PRA, immunosuppressive therapy, acute rejection, serum creatinina, graft loss and mortality were registered. Statistical analysis included 2, unpaired Student T test and Kaplan-Meier survival analysis with Log Rank test. Cox Analysis was also done.

RESULTS

1050 renal transplants were done from November 1990 to June 2011. 50 were excluded because follow-up was not longer than 3 months. 1000 consecutive renal transplant patients from January 1995 to June 2011 were included for analysis. Patients were divided in 2 groups: group A transplanted January 1995 to December 2004; group B transplanted January 2005 to June 2011. Etiology for end stage renal disease is unknown in 61% of cases, 11% developed renal disease to diabetes mellitus. 93% patient survival was observed at median follow-up and 84.9% graft survival at median follow-up (6 years). Biopsy proven acute rejection in group A 19.9 vs. 10% in group B. Two haplotype matching shows 92% graft survival. Diabetic patients exhibit 73% graft survival vs. other as hypertension (87%). PRA >0 and serum creatinine > 2.0 mg/dL increase risk for graft loss according to Cox analysis. CONCLUSION. Results are comparable to international data. Importance of developing regional transplant centers is emphasized.

[Prevalence of posttransplant hypertension in pediatric kidney transplant recipients: effect on long term allograft survival]

BACKGROUND

Arterial hypertension after renal transplantation has been identified as an adverse factor over the long term allograft function, thus identification and treatment of this entity has an impact on graft survival, as in patient survival. Studies about pediatric receptor populations have reported a prevalence of hypertension after renal transplantation ranging from 58 to 90%. In Mexico, the pre-valence of arterial hypertension after renal transplantation has been reported as 71% for an adult population attending a main hospital center in Mexico. No pediatric receptor studies in Mexico have reported the prevalence of hypertension after renal transplantation so far. The purpose of our study was to document the prevalence of arterial hypertension after renal transplantation in pediatric receptors, as well as its impact on allograft survival on a long term basis.

MATERIAL AND METHODS

We performed a retrospective analysis among pediatric patients who underwent renal transplantation at our center, Centenario Hospital Miguel Hidalgo, between years 2000 to 2006.

RESULTS

A total of 111 pediatric renal transplantation receptors were included, among whom 56 patients were classified as hypertensive (HT) and 54 patients were classified as nomotensive (NT) (one patient had to be excluded due to early allograft dysfunction). The mean age at the time of transplantation for the population under study was 14 +/- 3 years, with a predominance of male gender over females (1.5:1). In 89% of the transplantations, the source of the allograft was a living donor. The prevalence of arterial hypertension after renal transplantation in our population was 50.5%. Among patients in the HT group at least an episode of acute rejection presented in 8.9% (n=5) of the cases, compared to only 3.7% (n=2) of patients in the NT group with an episode of acute rejection. Likewise, the prevalence of chronic allograft nephropathy detected in the HT group was 11% (n=6) vs. 7% (n=4) in the NT group. The mean serum creatinine levels were 1.0 +/- 0.4 mg/dL for the HT group and 0.9 +/- 0.3 mg/dL for the NT group at the first month followup, however mean serum creatinine levels addressed at the last consult were different among groups: 1.7 +/- 1.8 mg/dL for the HT group versus 1.1 +/- 0.5 mg/dL for the NT group. Patient survival was similar for both groups (98%) and the follow-up period was also similar, being 39 +/- 12 months for the HT group and 39 +/- 17 months for the NT group. The multivariate Cox proportional hazard analysis demonstrated that the number of antihypertensive drugs needed to achieve the control of blood pressure, and the presence of chronic allograft nephropathy, were the independent risk factors associated to a graft loss at long term.

CONCLUSION

The prevalence of hypertension after renal transplantation in our pediatric population was 50.5%, which is clearly towards the inferior limit of the reported prevalence in other studies (50-90%). The tight control of blood pressure is an intervention that may have a significant impact on graft survival at long term. In our study, the severity of arterial hypertension after renal transplantation represented as the number of antihypertensive drugs needed to achieve control of blood pressure, as well as the presence of chronic allograft nephropathy, were the factors associated to long term graft loss.

[Systemic hypertension after kidney transplantation: associated risk factors and influence on graft survival]

Systemic hypertension after kidney transplant (HAPT) has been associated with a reduction in graft survival and increased morbidity and mortality of kidney transplant recipients. With the use of calcinuerin inhibitors, prevalence of HAPT has increased to 60-80%. The purpose of this study was to document the prevalence of HAPT in kidney transplant recipients attending the Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán" associated risk factors and the effect of hypertension in long term graft survival. We retrospectively reviewed the clinical charts of all the patients that underwent kidney transplant from 1984 to 1994. The following risk factors were studied: age, gender, cause of renal failure, presence of hypertension before kidney transplant, histocompatibility, acute rejection episodes, chronic rejection, serum creatinine values and use of cyclosporine. We divided subjects in two groups: normotensive (NT) and hypertensive (HT). HAPT included 3140/90 mmHg blood pressure level observed at least during two consecutive evaluations or the use of antihypertensive medication. We analyzed 215 grafts from 205 patients (10 patients had two kidney transplants); mean age at transplant of 30 +/- 9 years, 131 subjects were female and 84 male. One hundred and eighty eight patients (88%) displayed pretransplant hypertension. The mean follow up was 56+/-32 months. In the postransplant period 152 (71%) were HT and 63 (29%) NT. The HT group had significantly higher blood pressure and serum creatinine values than the NT group (P < 0.001), in spite of an adequate blood pressure control in 65% of the patients from the HT group. The NT group displayed a higher graft survival than the HT group; 60 +/- 30 months vs. 51 +/- 32 months respectively (p<0.01). Multivariate analysis did not show any risk factors independently associated with the development of HAPT. The prevalence of HAPT in our series is similar to the one reported in the literature. During the postransplant period there was a reduction of hypertensive patients (88% pretransplant vs. 71% postransplant). HAPT is a significant risk factor associated with long term survival of the graft.

In vivo IL-10 and TGF-beta production by PBMC from long-term kidney transplant recipients with excellent graft function: a possible feedback mechanism participating in immunological stability

BACKGROUND

Interleukin-10 (IL-10) and transforming growth factor-beta (TGF-beta) are Th2-derived multifunctional cytokines that exhibit potent immunoregulatory and anti-inflammatory properties which might prolong graft survival. The aim of this study was to explore whether spontaneous production of IL-10 and TGF-beta by blood mononuclear cells correlates with excellent long-term graft function.

METHODS

A cross-sectional study was carried out in 32 kidney transplant recipients, without albuminuria, treated with azathioprine and prednisone. Spontaneous IL-10 and TGF-beta were measured by enzyme-linked immunosorbent assay in supernatants from 24 h cultured unstimulated peripheral blood mononuclear cells. Both cytokines were also determined in 10 healthy kidney donors.

RESULTS

There was no correlation between IL-10 or TGF-beta with any variable tested, namely age, SCr, histocompatibility, and post-transplant follow-up. In vivo IL-10 production displayed a statistical trend to be higher in transplant recipients than in controls (362.3 +/- 465, range 12.5-1929.3 pg/ml, and 189 +/- 170, range 4.17-485.7 pg/ml, respectively; p = 0.08), whereas no difference was observed in TGF-beta among the same groups (134.7 +/- 79.2, range 68-421 pg/ml, and 121.4 +/- 25.8, range 75-151 pg/ml, respectively). Interestingly, a statistically significant inverse correlation was observed between IL-10 and TGF-beta in kidney transplant recipients (p = 0.03).

CONCLUSIONS

The higher IL-10 production observed in long-term kidney transplant recipients supports the notion that this cytokine contributes in decreasing allogenic immune responses and allows prolongation of allograft survival. The balance between TGF-beta and IL-10 may be of paramount importance in graft acceptance.

[Renal graft survival in patients with systemic lupus erythematosus]

BACKGROUND

End-stage renal disease is an important cause of morbidity and mortality in patients with systemic lupus erythematosus (SLE). In 1975, the US Renal Transplant Registry reported the first lupus patients, who received a renal transplant. This study reported 60% and 55% patient/graft survival respectively at a mean time of two years; these results were similar to those of non-lupus transplanted patients in this same post-transplant lapse time. Renal transplantation is a world wide accepted therapeutic option in the treatment of SLE patients.

PATIENTS AND METHODS

In order to identify the risk factors associated to renal graft loss in SLE patients and to compare graft survival between these patients and control transplant patients, matched by age, gender, haplotype match, and transplant date (+/- three years), we performed a retrospective analysis of all SLE patients that received a renal transplant in our Institute.

RESULTS

From 1967 to March 1997, 25 (5.5%) out of 452 renal transplants were performed in 22 SLE patients, mean age 29 +/- 10 years, 20 were female (90%). In 18 patients (85.7%) we obtained pre-transplant histological diagnosis: 13 (72%) type IV glomerulonephritis according to the OMS classification, three (17%) type VI, and two (11%) type III. Twelve patients (57%) were subjected to hemodialysis in the pre-transplant period and none (43%) to peritoneal dialysis. The time elapsed between the diagnosis of SLE and the start of dialysis was 50 +/- 70 months, the time on dialysis was 18 +/- 17 months, the post-transplant renal follow-up 46.9 +/- 41.5 months, and the graft source: 18 (78%) from living related (three sharing 0 haplotypes, 12 sharing 1 haplotype, and three sharing 2 haplotypes), and five (22%) from cadaver donors. Triple drug immunosuppresive therapy (cyclosporine, azathioprine, and prednisone) was employed in 17 patients and double drug therapy (azathioprine and prednisone) in the remaining six cases. We registered seven acute rejection episodes in five patients (30%), one of them lost the graft. Five patients presented a post-transplant thrombotic event, two of these were in the graft's artery. In two patients post-transplant SLE activity was documented, one case in with renal activity in the graft and the other with extrarenal activity. Risk factors analyzed for graft loss: number of pre-transplant thrombosis events, time elapsed between diagnosis of SLE at start of dialysis (< or = 6 months), time on dialysis (< or = 12 months), graft source, chronic rejection, and follow-up were not significant; in contrast, post-transplant thrombosis was the only identified risk factor for graft loss. Graft survival analysis at 50 months in SLE transplanted patients versus control non-SLE transplanted patients did not show significant differences (74% vs. 83%, log rank 0.11).

CONCLUSIONS

Post-transplant thrombosis was identified as a risk factor for graft loss. In concordance with recent studies, pre-transplant thrombosis, time elapsed between diagnosis of SLE at start of dialysis and time on dialysis were not risk factors for graft loss in this study. Graft survival in renal transplants recipients with SLE was not different from that of the general renal transplant population.

[Clinical course and prognostic factors in lupus nephropathy]

BACKGROUND

The present study was designed to know the clinical course of lupus nephritis and the risk factors associated with the development of end stage renal disease.

METHODS

This a retrospective study performed in a cohort of 154 patients with biopsy proven lupus nephritis that were seen in our hospital between 1984 and 1990. The clinical records of all patients were reviewed in order to collect the following information at the time of the biopsy: age, sex, number and type of lupus criteria according with the American College of Reumathology, mean arterial pressure, serum creatinine, BUN, and albumin, as well as urinary protein excretion. The follow up was registered from the day the biopsy was performed to one of the following end points: end stage renal disease (defined as requirement of chronic dialysis), death or the end of study. All biopsies were analyzed by light microscopy to obtain the hystological subtype of lupus nephritis (WHO classification) and when type IV was diagnosed, the activity and chronicity indexes were also assessed. Kaplan-Meier survival tables were constructed. The association of clinical and laboratory variables with the development of end stage renal disease was obtained by log rank analysis. Variables obtained as significant were used to evaluate their individual impact using either the Cox multivariate proportional hazard method.

RESULTS

Follow up was complete in 144 patients with a follow up time of 68 +/- 38 months. Ninety three patients were female with mean age of 28 +/- 9 years. At the time of the biopsy, renal manifestations had been present for 35 +/- 38 months and the number of lupus criteria per patient were 4 +/- 1. The clinical picture at the time of the biopsy was: nephrotic syndrome in 60%, non nephrotic proteinuria in 40%, and nephritic syndrome in only 2%. The hystological type of lupus nephritis was: I in 2%, II in 8%, III in 6%, IV in 71% and V in 11%. At the end of the study 28 patients developed end stage renal disease. For the whole group the survival of renal function was 85% at 70 months and 70% at 140 months. All, but one patient that developed end stage renal disease exhibited type IV nephropathy. In this subpopulation the mean activity and chronicity indexes were 8.5 +/- 3.5 and 3.1 +/- 2.4, respectively. By multivariate analysis the strongest predictors of end stage renal disease were the serum creatinine at the time of the biopsy, chronicity index, and age. The higher the serum creatinine and chronicity index at the time of biopsy, the higher the probability of developing end stage renal disease.

CONCLUSIONS

We conclude that the clinical course of lupus nephritis in our population is similar to that seen in other series. The variables indicating advanced renal disease, such as high serum creatinine and chronicity index, were the strongest predictors of end stage renal disease.

[Percutaneous kidney biopsy, analysis of 26 years: complication rate and risk factors; comment]

Percutaneous renal biopsy is an invasive procedure that can result in major and minor complications. The objective of this study was to know the frequency and type of complications in relation with this procedure, as well as the efficacy to obtain enough material for diagnosis.

METHODS

Retrospective study. We review the charts of patients to whom a percutaneous renal biopsy of native kidneys was done between January 1970 and March 1996. The following data were obtained: age, gender, clinical and histopathological diagnosis, complications associated with the procedure (minor: hematuria, local infections, hematoma; major: transfusions, severe infections, surgery, nephrectomy, arteriography, embolism and death).

RESULTS

We analyzed 1,005 renal biopsies in 840 patients, mean age 37.7 +/- 13.1 years, 67% female. There were no complications in 88.8% (893 biopsies), minor complications in 8.65% (87 biopsies) and only in 2.4% of the procedures major complications. We divided the cases in two groups: percutaneous renal biopsy without complications (n = 893, 89%) and with complications (n = 112, 11%). The most frequent complications were hematuria (91 cases, 9.1%) and perirenal hematoma (29 cases, 2.7%). In these cases transfusion was required in 2.4% (26). Infectious complications were: urosepsis in 7 cases (0.7%), bacteremia, sepsis and perirenal abscesses (1 case each, 0.1%). One patient died because of multiple complications (0.1%). We observed greater risk of major complications on patients in those who biopsy was done because of acute renal failure (OR 4.03, p < 0.003).

DISCUSSION

In our experience percutaneous renal biopsy is a low risk procedure. Most complications are minor and without clinical repercussion. There must be a strict selection criteria of the patients to whom percutaneous renal biopsy is going to be done because of the risk of severe complications.

[Four cases of parathyroid cancer]

Parathyroid carcinoma is a rare cause of primary hyperparathyroidism with a prevalence ranging between 0.5 and 4%. Because of their aggressiveness, prompt diagnosis and treatment are mandatory. A parathyroid carcinoma was found in four patients (4.5%) of 88 patients who underwent surgical cervical exploration for primary hyperparathyroidism at the Institute Nacional de la Nutrición in a period of seven years. Our paper gives the clinical characteristics, diagnosis, treatment and outcome of the four patients.

[Clear-cell eccrine carcinoma of the plantar region. Follow-up of a case using histochemistry, immunohistochemistry, and flow cytometry]

Clear cell eccrine carcinomas of the skin are rare and have been reported with several names. Of the 47 cases found in the literature, only one had the lesion in the sole. The present case is a 38 year old woman with an 18 year history of a 3.2 cm lesion in the lateral portion of the sole in the right foot. The patient developed inguinal metastases four and five months after the plantar resection, and suffered a local recurrence on two occasions. The histopathologic analysis of the sole lesion showed a neoplasm with more than 80% of clear cells, and less clear cells in the metastatic and recurrent lesions. Clear cells showed diffuse positivity to PAS with diastase lability. PAS reactivity was related to the presence of clear cells. Focal reactivity of mucin and colloidal iron in sebaceous-like cells and tubular structures was seen. Also, we found diffuse cytoplasmic and membrane surface positivity of epithelial membrane antigen in the clear cells, and focal in poroid and sebaceous cells and in tubular structures. The carcinoembryonic antigen showed a focal positivity in poroid and sebaceous cells and in tubular structures. We also identified focal positivity of S-100 protein in the sebaceous-like cells. Cytophotometric measurement of the nuclear DNA showed euploid cells in the primary and metastatic lesions. We conclude that clear cell eccrine carcinomas comprise a heterogeneous group of lesions with variable biological behavior, but with morphological, histochemical and immunohistochemical markers useful in their diagnosis.