Peripheral Blood Regulatory T Cells Are Diminished in Kidney Transplant Patients With Chronic Allograft Nephropathy.

BACKGROUND: Our aim in this study was to assess peripheral blood CD4+CD25+FOXP3+ regulatory T cell (Treg) levels in patients with chronic allograft nephropathy (CAN) 1 year after kidney transplantation. METHODS: Twelve renal transplant patients with an initial onset of CAN, 12 patients with chronic kidney disease (CKD) stage G5 on dialysis, and 13 healthy control individuals were evaluated regarding the proportion of Tregs in their peripheral blood via flow cytometry. RESULTS: The renal transplant patients with CAN had a significantly lower proportion of Tregs than the hemodialysis CKD patients and healthy controls (P < .0001). In contrast, the hemodialysis CKD patients showed higher levels of Tregs than the renal transplant patients with CAN and the healthy controls (P < .0001). CONCLUSION: The high level of peripheral blood Tregs in the hemodialysis CKD patients suggests a chronic inflammatory state. However, the low frequency of Tregs in the peripheral blood from the renal transplant patients with CAN suggests an unfavorable prognosis for allograft immune tolerance.

Analysis of PTPN22, ZFAT and MYO9B polymorphisms in Turner Syndrome and risk of autoimmune disease.

Turner syndrome (TS) is one of the most common sexual chromosome abnormalities and is clearly associated with an increased risk of autoimmune diseases, particularly thyroid disease and coeliac disease (CD). Single-nucleotide polymorphism analyses have been shown to provide correlative evidence that specific genes are associated with autoimmune disease. Our aim was to study the functional polymorphic variants of PTPN22 and ZFAT in relation to thyroid disease and those of MYO9B in relation to CD. A cross-sectional comparative analysis was performed on Mexican mestizo patients with TS and age-matched healthy females. Our data showed that PTPN22 C1858T (considered a risk variant) is not associated with TS (X2  = 3.50, p = .61, and OR = 0.33 [95% CI = 0.10-1.10]). Also, ZFAT was not associated with TS (X2  = 1.2, p = .28, and OR = 1.22 [95% CI = 0.84-1.79]). However, for the first time, rs2305767 MYO9B was revealed to have a strong association with TS (X2  = 58.6, p = .0001, and OR = 10.44 [95% C = 5.51-19.80]), supporting a high level of predisposition to CD among TS patients. This report addresses additional data regarding the polymorphic variants associated with autoimmune disease, one of the most common complications in TS.

New genetic abnormalities in non-21α-hydroxylase-deficiency congenital adrenal hyperplasia.

Congenital adrenal hyperplasia comprises a group of autosomal recessive disorders of sexual differentiation and development that occur due to deficiencies in steroidogenic enzymes within the adrenal gland. Using clinical, biochemical, and sequencing data, we describe non-21α-hydroxylase deficiencies in 6 individuals from 4 families originating from endogamic regions in Mexico. Three individuals had 11ß- hydroxylase deficiencies caused by 2 hitherto unreported mutations (P442L substitution and an 11-bp insertion in exon 5 of CYP11B1), while 3 individuals had 17α-hydroxylase/17,20-lyase deficiencies. Sequence-tagged site analysis of 8 individuals from 1 endogamic region suggested that the mutations likely occurred as a result of a founder effect. Although non-21α-hydroxylase enzymatic defects are rare in most populations, characterization of new mutations is important in order to understand the demographic, clinical, biochemical, and molecular variations that exist, and for both active and preventative management in individuals and their communities.

Alteraciones en el gasto energético en reposo y parámetros respiratorios en pacientes con síndrome de Prader-Willi / Abnormalities in energy expenditure and respiratory parameters in patients with Prader Willy syndrome

Introducción: El síndrome de Prader Willi (SPW) es un trastorno genético complejo relacionado con insuficiencia hipotalámica. Una de las manifestaciones clínicas es la obesidad asociada a un desequilibrio entre la ingesta y el gasto energético, debido a la hiperfagia y a la baja tasa metabólica que presentan estos pacientes. Distintos procedimientos e intervenciones han sido utilizadas para tratar de limitar el consumo de alimentos, pero no hay resultados contundentes al respecto. Objetivo: Comparar el gasto energético en reposo (GER) de pacientes con SPW con pacientes obesos sin el Síndrome. Sujetos y métodos: Se realizó un estudio comparativo observacional, transversal y descriptivo en pacientes con SPW y pacientes obesos sin SPW pareados por edad, sexo e IMC. Se midió por medio de calorimetría indirecta el GER de los pacientes, así como por antropometría, IMC, pliegue cutáneo de tríceps y bíceps. Se utilizó una prueba T de Student para muestras independientes que comprobara la homogeneidad de los pacientes y se realizó una serie de análisis de ANCOVA sobre cada uno de los parámetros de la calorimetría indirecta. Resultados: Se analizó 20 pacientes mestizo-mexicanos entre 2 y 26 anos: 10 pacientes con SPW y 10 controles obesos. Se identificó una diferencia estadísticamente significativa en el GER, resultando 17.67% menor en los sujetos con SPW; así también en el volumen de oxígeno (mil/min) y volumen TIDAL (p < 0.05). Conclusión: Pacientes con SPW per se producen modificaciones en el GER a lo largo de la vida en comparación con los pacientes con obesidad.

Introduction: Prader Willi Syndrome (PWS) is a complex genetic disorder with many manifestations relating to hypothalamic insufficiency. One such feature is obesity associated with an imbalance between caloric intake and expenditure due to hyperphagia and slow metabolic rate. Different procedures, as the use of appetite suppressants, surgical interventions and change in behavioral techniques have been used to try to limit food intake, but there is not convincing results about it. Aim: To compare the resting energy expenditure (REE) in PWS patients with obese patients without the syndrome matched by age and BMI (Body Mass Index). Subjects and methods: We conducted a comparative, observational and descriptive study in PWS and obese patients, matched for age, sex and BMI. RER was measured by indirect calorimerty and by anthropometry (BMI, skin-fold triceps and bíceps). A t-Student test for independent samples was used to demonstrate homogeneity between subjects and a series of ANCOVA analysis was performed on each of the parameters displayed by the indirect calorimetry. Results: Twenty mestizo-mexican patients, 10 with PWS and 10 with obesity were analyzed matched by age, BMI and gender. We found a statistically significant difference in the REE, the volume of oxygen (ml/min) and tidal volume (p <0.05). Conclusions: Prader Willy Syndrome per se produces changes in the REE in comparison with patients with only obesity.

Mix gonadal dysgenesis associated with ring Y chromosome mosaics in a phenotypic male.

Ring chromosomes are present in 1 in 25,000 human fetuses; 99% arise de novo while less than 1% of rings are inherited. This chromosomal rearrangement may arise through a cytogenetic mechanism involving breaks in chromosome arms and fusion of the proximal broken ends, leading to a loss of distal material. Most patient Y ring chromosomes are present in a 45,X/46,X,r(Y) mosaic karyotype; molecular analyses of infertile men have shown that it is not rare to find r(Y) in these patients. However, the clinical spectrum in those cases with a 45,X cell line is broad and depends on the percentage of the monosomic cell line in different tissues. Y chromosome abnormalities and 45,X mosaic karyotypes are often associated with disorders of sex determination. Here, we report a male patient with hypospadias, cryptorchidism and a mosaic karyotype containing a low proportion of 45,X monosomic cells and multiple ring Y chromosomes in peripheral blood. Clinical, surgical, and molecular evidence was sufficient for a diagnosis of mixed gonadal dysgenesis. We suggest that a detailed cytogenetic and molecular analysis should be done in all males with bilateral descended testes and infertility.

Intracranial germ cell tumors: association with Klinefelter syndrome and sex chromosome aneuploidies.

Intracranial germ cell tumors (ICGCTs) occur mainly in male children and adolescents. Polyploidy of the X chromosome and X hypomethylation have been suggested as mechanisms of malignant transformation independently of the histological tumor type. On the other hand, several reports associate these tumors with Klinefelter's syndrome (KS). Recent reports indicate that KS patients have an increased relative risk for development of malignant mediastinal germ cell tumors and also around 8% of male patients with primary mediastinal tumors have KS. In an attempt to explore the frequency of KS amongst patients with ICGCTs and to confirm the presence of X chromosome polyploidies in these tumors, we studied 13 young male patients with ICGCTs. Paraffin-embedded tumoral and normal tissues were studied by FISH. KS was found in 15% of the cases, demonstrating that this constitutive aneuploidy may be related to carcinogenesis. When tumor and non-tumor tissues were compared, statistically significant X and Y chromosome polyploidies in tumors were revealed. These results emphasize that aneuploidies are involved in ICGCT tumorigenesis.

Sex hormone-binding globulin stimulates chorionic gonadotrophin secretion from human cytotrophoblasts in culture.

The effects of sex hormone-binding globulin (SHBG) on the secretion of human chorionic gonadotrophin (HCG) and cAMP by cultured human cytotrophoblasts were investigated. Cytotrophoblasts obtained from normal term placentae were cultured in serum-free medium with or without the addition of human SHBG. The presence of SHBG in the medium increased the release of HCG and the accumulation of cAMP. Ligand-free SHBG was able to raise both HCG and cAMP concentrations and the maximal response was observed with 1 nM of the steroid-binding globulin. Addition of either oestradiol or 5alpha-dihydro-testosterone (DHT) to cultures previously incubated with SHBG in a final molar ratio of 1:10 resulted in a further increase of HCG and cAMP concentrations. This effect was blocked when cultured placental cells were exposed to SHBG that was previously saturated with DHT or when incubated in the presence of steroids only. The results of the present study provide evidence for the in-vitro regulation of HCG secretion by SHBG and further support the concept that this steroid-binding protein may act as a mediator of steroid action at the cellular level. Finally, the increase in cAMP suggests that SHBG receptor located in the surface of syncytiotrophoblast membranes is coupled to adenylate cyclase as part of the G-protein receptor family. Our results may provide new insights into the biological implications of extracellular steroid-binding proteins as well as new perspectives on the endocrinology of pregnancy.

A bioactive 60-kilodalton prolactin species is preferentially secreted in cultures of mitogen-stimulated and nonstimulated peripheral blood mononuclear cells from subjects with systemic lupus erythematosus.

We have evaluated the production of PRL by human peripheral mononuclear cells (PBMNC) from normal subjects and patients with systemic lupus erythematosus (SLE). Conditioned medium prepared from basal and Con-A-stimulated PBMNC was assessed for the presence of PRL-like by its ability to stimulate growth of PRL-responsive Nb2 rat lymphoma cells. In the presence or absence of Con-A, SLE PBMNC secrete significantly higher (P < 0.001) amounts of bioactive PRL-like species than normal cells. Growth of Nb2 cells by conditioned medium was inhibited with specific antiserum to human PRL. Western blotting using a polyclonal antibody to human PRL revealed a single 60-kDa PRL-like species in both normal and SLE PBMNC extracts, the immunoreactivity of which was preferentially found in SLE subjects. With the use of reverse transcription-PCR an expected 633-bp band was observed, and its similarity to pituitary PRL was further confirmed by Southern blot analysis with human PRL complementary DNA as a probe. We conclude that a high molecular mass PRL-like species is synthesized and secreted by PBMNC, and patients with SLE have an increased secretion of lymphocyte-derived PRL-like material.

Biologically active steroid and thyroid hormones stimulate secretion of sex hormone-binding globulin by human term placenta in culture.

In this study, the influence of steroid and thyroid hormones and epidermal growth factor on the production of SHBG by placental tissue explants was investigated. Explants of trophoblastic tissue obtained from normal term placentas were cultured for 48 h in serum free culture medium, and then for an additional 24 h period in the presence or absence of various concentrations of either estradiol (0.25-5 nM), testosterone (0.5-500 nM), triiodothyronine (0.01-100 nM) or EGF (2-40 microM), respectively. Human SHBG concentration in culture media was estimated on each day by specific two-site time-resolved fluoroimmunometric assay and the results expressed as pmol/mg tissue protein. Binding characteristics and molecular structure of secreted SHBG were determined by [3H]5 alpha-DHT binding assays and Western blot analysis, respectively. Estradiol and triiodothyronine but not testosterone increased significantly (p < 0.05 vs. control) the secretion of SHBG into the culture media. Addition of EGF did not significantly change the production of SHBG at the various concentrations studied. [3H] 5 alpha-DHT binding assays and Western blot analysis of placental SHBG resulted in identical binding affinities (Kd 2.0 +/- 0.16 x 10(-9)M) and molecular structure to those obtained in serum from normal pregnant women. These findings support and extend previous observations by our laboratory indicating that SHBG gene is expressed in the placenta and provide further evidence on the hormonal regulatory characteristics of this steroid-binding protein in cultured placenta.

Steroid 5 alpha-reductase activity in the harderian glands of male and female Syrian hamster (Mesocricetus auratus).

The activity of the enzyme steroid 5 alpha-reductase in Harderian glands of adult syrian hamsters was assessed by measuring the conversion of testosterone (T) to 5 alpha-dihydrotestosterone (DHT). The optimal conditions for this reaction were determined in vitro using whole gland homogenates and [3H]testosterone as substrate. Enzyme activity was maximal at pH 5.5. The Michaelis-Menten constant of the Harderian enzyme for T was 4.6 +/- 1.2 x 10(-6) M in females and 4.2 +/- 0.39 x 10(-6) M in males, estimated by Eadie-Hofstee plots. On the basis of relative maximum velocity values, there was 9 or 10 times more 5 alpha-reductase in females (2.8 +/- 0.67 nmol/mg protein/hr) than in males (0.289 +/- 0.029 nmol/mg protein/hr). Consistently, glands of intact male hamsters had lower 5 alpha-reductase activities than those of females. Castration of males significantly increased the enzymatic activity, which within 4 weeks reached female-like values. The levels of 5 alpha-reductase mRNA also increased with castration. There was a direct correlation between activity and mRNA levels of the enzyme in castrated male glands. Further, the administration of T or DHT to ovariectomized hamsters led to intact male values in the enzymatic activity of the gland. The sex differences in 5 alpha-reductase activity may be of relevance to the differential regulation exerted by androgen upon the physiology of male and female glands. The results are consistent with the view that 5 alpha-dihydrotestosterone is the active androgen in the Harderian gland.