Umbilical cord blood transplantation in hematologic diseases in patients over 15 years old: long-term experience at the Pontificia Universidad Católica de Chile.

Most patients who require a sibling stem cell transplantation do not have a matched donor. In our experience, only 1/3 patients have a matched unrelated donor (MUD); therefore, the majority of the patients will require umbilical cord blood (UCB). Patients treated for hematologic diseases with UCB transplants were included. UCB selection and conditioning regimens were performed according to the Minnesota group. Graft-versus-host disease (GVHD) prophylaxis, infection prevention, and patient care were performed according to institutional guidelines. We analyzed patients and graft demography, neutrophil and platelet recovery, chimerism kinetics, GVHD incidence, overall (OS), progression-free survival (PFS) and transplant-related mortality (TRM). We included 29 patients with a median age of 34.8 years (range 15-55). Eighteen were male and the median weight was 72.6 kg (range 54-100). Nineteen patients had acute leukemia. Myeloablative (MA) conditioning was used in 27 patients. Seventeen received double UCB (DUCB) grafts. Median total nucleated cell (10(7)/kg) was 4.2 (range 3.9-4.9) and 4.4 (range 2.8-6.3) for single UCB (SUCB) and DUCB transplants, respectively. Median time for neutrophil engraftment was 24.7 (range 14-43) and 25.8 days (range 14-52) after SUCB and DUCB transplants, respectively. Median time for platelet engraftment was 147 (range 30-516) and 81 days (range 37-200) after SUCB and DUCB transplants, respectively. All the patients receiving MA conditioning had >95% chimerism shortly after transplant. Cumulative incidence of grades II-IV and III-IV acute GVHD was 41% and 20%, respectively. Localized chronic GVHD was seen in 14% of the patients. Median follow-up was 16.7 months (range 1-63). Five-year OS and PFS were 38% and 39%, respectively. One-year TRM was 42%. UCB transplantation is associated with potential cure of hematologic malignancies and our results are similar to other series. Studies are needed to decrease mortality and improve immune reconstitution.

Large mitochondrial DNA deletion in an infant with addison disease.

BACKGROUND: Mitochondrial diseases are a group of disorders caused by mutations in nuclear DNA or mitochondrial DNA, usually involving multiple organ systems. Primary adrenal insufficiency due to mitochondrial disease is extremely infrequent and has been reported in association with mitochondrial DNA deletion syndromes such as Kearns-Sayre syndrome. AIM: To report a 3-year-old boy with Addison disease, congenital glaucoma, chronic pancreatitis, and mitochondrial myopathy due to large mitochondrial DNA deletion. METHOD: Molecular analysis of mitochondrial DNA samples obtained from peripheral blood, oral mucosa, and muscle tissue. RESULTS: A novel large mitochondrial DNA deletion of 7,372bp was identified involving almost all genes on the big arch of mtDNA. CONCLUSIONS: This case reaffirms the association of adrenal insufficiency and mitochondrial DNA deletions and presents new evidence that glaucoma is another manifestation of mitochondrial diseases. Due to the genetic and clinical heterogeneity of mitochondrial disorders, molecular analysis is crucial to confirm diagnosis and to allow accurate genetic counseling.

Testicular adrenal rest tumors and Leydig and Sertoli cell function in boys with classical congenital adrenal hyperplasia.

CONTEXT: Infertility observed in adult males with congenital adrenal hyperplasia (CAH) has been associated with testicular adrenal rest tumors (TART) that may originate during childhood. OBJECTIVE: Our objective was to describe the prevalence of TART and Sertoli and Leydig cell function in a group of boys aged 2-10 yr with CAH and to compare prevalence with that of a control group. DESIGN: From August 2005 to January 2007, 19 patients with classical CAH (CAH group) were referred from seven endocrinology centers. METHODS: We studied 19 subjects in the CAH group and, as a control group, 13 boys from the community that did not have testicular diseases. A complete physical exam was performed. High-resolution ultrasound was used to determine TART prevalence. Inhibin B and anti-Müllerian hormone were used as Sertoli cell markers. The ratio between basal testosterone levels and testosterone levels 72 h after beta-human chorionic gonadotropin (5000 U/m2) treatment [(T72- T0)/T0] was used to evaluate Leydig cell response. RESULTS: CAH and control groups were comparable in chronological age (5.9 vs. 5.6 yr; P = 0.67) and bone age/chronological age ratio (1.09 vs. 1.03; P = 0.09). TART prevalence was four of 19 (21%) in the CAH group. Lower values for inhibin B (49.2. vs. 65.2 pg/ml; P = 0.018), anti-Müllerian hormone (70.1 vs. 94.2 ng/ml; P = 0.002), and (T72- T0)/T0 (5.6 vs. 13.6; P < 0.01) were observed in the CAH group. CONCLUSION: TART in prepubertal males with classic CAH could be found during childhood. We also report differences in markers of gonadal function in a subgroup of patients, especially in those with inadequate control.

Y chromosome sequences in Turner's syndrome: association with virilization and gonadoblastoma.

UNLABELLED: The presence of Y chromosome fragments in patients with Turner's syndrome is known to increase the risk of gonadoblastoma and virilization. Y chromosome material is detected in up to 6% of patients with Turner's syndrome by karyotype. By DNA analysis, Y chromosome sequences have been reported in 0-60% of patients. The putative gonadoblastoma gene has been mapped to the pericentromeric region of the Y chromosome increasing the interest in studying these sequences. AIMS: 1. To determine the frequency of occult Y chromosome sequences in patients with Turner's syndrome. 2. To analyze the clinical implications of Y sequences detected by karyotype and occult Y sequences. STUDY DESIGN: Cross-sectional study of 58 patients with Turner's syndrome (30 45,X; two with structural anomalies; 26 mosaic [two of whom were 45,X/46,XY]). SRY, TSPY and DYZ3 sequences were amplified by PCR using genomic DNA from peripheral blood. RESULTS: All three Y chromosome sequences were found in one out of 56 patients whose karyotype was not suggestive of having Y chromosome material and in one patient with 45,X/46,Xr(X) karyotype. The patients with the ring chromosome and 45,X/46,XY karyotype underwent surgery and were found to have a gonadoblastoma and dysgerminoma. The four patients with Y chromosome material had non-virilized female genitalia. CONCLUSIONS: Analysis by PCR was more sensitive in detecting Y chromosome sequences than conventional karyotype. The presence of Y material was not associated with virilization. We confirmed the association of Y fragments and gonadoblastoma at an early age.

[Identification of mutation in the gene cystic fibrosis transmembrane regulator (CFTR) in Chilean patients with cystic fibrosis]. / Identificación de mutaciones en el gen CFTR en pacientes chilenos con fibrosis quística.

BACKGROUND: Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the CFTR gene, that codes for a chloride channel located in the apical surface of epithelial cells. The main role of this protein is the regulation of chloride transport, and secondarily, of sodium and water to the extracellular space. More than 900 gene mutations have been described, and their relative frequency in different populations depends on their ethnic origin. AIM: To report the findings of Chilean patients with cystic fibrosis, in whom the presence of 20 common mutations was analyzed. PATIENTS AND METHODS: Fifty seven patients with established diagnosis or suspicion of CF were studied. The simultaneous identification of 20 mutations and the normal delta F508 allele was done using polymerase chain reactions with a commercial assay. RESULTS: Eight mutations were found. Fifty patients fulfilled diagnostic criteria proposed by the Consensus Panel of the CF Foundation and 66% of alleles were identified in this group. delta F508 mutation was found in 45%. We did not identify mutations in any of the remaining 7 patients. CONCLUSIONS: Our results suggest that the majority of undetected mutations are associated with atypical phenotypes or that some patients in this series could have other diseases. We recommend to include mutation analysis in the evaluation of Chilean patients with CF. It is useful to establish prognosis and genetic counselling.

[High prevalence of subclinical thyroidal disease among individuals attended in health control]. / Alta prevalencia de enfermedad tiroidea subclínica en sujetos que concurren a control de salud.

BACKGROUND: There is no information about the prevalence of thyroidal diseases in the general Chilean population. AIM: To assess the prevalence of thyroidal diseases in individuals attended in occupational health examinations. SUBJECTS AND METHODS: Four hundred seventy two individuals were examined between 1998 and 1999. In all, serum levels of thyroid hormones, TSH and anti thyroidal antibodies (anti microsomal, anti thyroid peroxidase and anti thyroglobulin) were measured. RESULTS: Forty four subjects were excluded from the study due to an incomplete medical record and 18 due to a personal history of thyroidal disease. Abnormal serum levels of thyroid hormones or TSH were detected in 28 subjects (6.8%). Four (1%) had hypothyroidism, 23 a subclinical hypothyroidism (5.6%) and one (0.2%) had hyperthyroidism. In 87 subjects (21.2%) at least one of the antibodies was positive. Positive anti thyroid antibodies were found in 14 of 28 subjects (50%) with abnormal thyroid hormone levels, compared with 73 of 382 subjects (19.1%) with normal thyroid hormone levels. Thyroid dysfunction was twice as frequent in women than in men. CONCLUSIONS: In this sample, a 6.8% prevalence of abnormal thyroid function tests was detected.

Mutations in the CYP21 B gene in a Chilean population with simple virilizing congenital adrenal hyperplasia.

Steroid 21-hydroxylase deficiency (21OHD) compromises about 95% of all cases of congenital adrenal hyperplasia. We have characterized the disease-causing mutations in the steroid 21-hydroxylase genes of 19 Chilean patients (12 females and 7 males) with the simple virilizing (SV) form of 21OHD and compared them with other SV-populations. Using allele-specific polymerase chain reaction, we identified lesions in 28 chromosomes out of 38 tested (73.7%). The most frequent finding was the mutation I173N=12/38 (31.6%) similar as described in Caucasian, Asian and other Hispanic populations, where this mutation represents around 20-40% of the genetic defects in the CYP21B gene. The mutation V282L=4/38 (10.5%) and deletion (Del) or large gene conversion (LGC)=3/38 (7.9%) were also frequently detected. Only 2 alleles carried the mutation I2 splice (5.3%), this frequency is lower than that reported in Caucasian or in Mexican populations. We did not find alleles with the mutations R357W, Cluster E6, P31L and P454S in these patients. The complete genotype was determined in 11/19 patients (58%) and one allele in 6/19 patients (31.6%). In summary, about 30% of the Chilean population with SV 21OHD presented the missense mutation I173N as described in other populations. The frequency of the other lesions showed differences even between populations with similar genetic background.

[Measurement of 17 OH progesterone in blood in Chilean newborns: antecedents for implementing a grogram for the neonatal detection of congenital adrenal hyperplasia]. / Medición de 17-OH progesterona sanguínea en recién nacidos chilenos: antecedentes para implementar un programa de detección neonatal de hiperplasia suprarrenal congénita.

BACKGROUND: The early diagnosis and therapy of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency can prevent adrenal crises and erroneous gender assignment in affected newborns. To achieve this goal neonatal mass-screening programs have been developed, measuring blood 17 alpha-hydroxyprogesterone (17OHP). In Chile there is no experience with this type of screening. AIM: To develop a method for measuring 17OHP in filter paper blood specimens. To obtain reference ranges and determine neonatal 17OHP threshold levels according to gestational age and birth weight. To analyze factors affecting the cost-efficiency ratio and suggest recommendations for the organization of a neonatal screening program for CAH in Chile. MATERIAL AND METHODS: Nine hundred twenty two newborns were studied. 17OHP was measured using double antibody radioimmunoassay in filter paper blood samples obtained 48 h after birth. Reference ranges were determined according to gestational age and birth weight and a cutoff point of 25 ng/ml was established. RESULTS: Seventeen newborns had 17OHP over the cutoff value. They were assessed by a pediatric endocrinologist and in none of them, CAH was confirmed. Therefore the false positive rate of the determination was 1.8%. Among these newborns with elevated 17OHP, 66% had a birth weight below 1.5 kg and 5.8%, a birth weight between 1.5 and 2.5 kg. The cost per reported result was US $ 1. Timing of the recall was between the 3 and 10 days of life. No newborn missed the follow-up. DISCUSSION: To increase the cost-efficiency ratio of an eventual neonatal screening program, newborns with birth weights below 1.5 kg should be excluded and cutoff points should be defined according to birth weight (Rev Méd Chile 2000; 128: 1113-18).

[Detection of thyroglobulin autoantibodies and potential interference with serum thyroglobulin measurement]. / Autoanticuerpos anti-tiroglobulina: detección y posible interferencia en la medición de tiroglobulina en suero.

BACKGROUND: Thyroglobulin measurement is useful for the follow up of patients subjected to total thyroidectomy for differentiated thyroid carcinoma. Thyroglobulin autoantibodies may interfere with its determination. AIM: To measure thyroglobulin autoantibodies and their interference with thyroglobulin determination. MATERIAL AND METHODS: The presence of thyroglobulin autoantibodies was investigated in 801 serum samples sent to the laboratory for measurement of thyroglobulin levels. A serum was considered positive for these autoantibodies when radioactivity corresponding to 125I-thyroglobulin bound to thyroglobulin autoantibodies, precipitated with human gamma globulin, exceeded in 1.4 times that of a negative sera pool. In positive sera, thyroglobulin autoantibody concentration was measured and its interference with thyroglobulin radioimmunoassay was assessed through a recuperation test using exogenous thyroglobulin. RESULTS: Thyroglobulin autoantibodies were detected in 149 sera (18.6%). Of these, 65 had a recuperation that fluctuated between 1 and 80%. Thyroglobulin autoantibody concentration was negatively correlated with recuperation percentages (r = -0.64; p < 0.001) but not with thyroglobulin concentrations (r = 0.08). Thyroglobulin was higher in positive sera with a recuperation over 80% than in sera with a recuperation of less than 80% (12.7 +/- 1.7 and 5.9 +/- 0.6 ng/ml, respectively; p < 0.001). CONCLUSIONS: Thyroglobulin autoantibodies interfere with thyroglobulin measurement by radioimmunoassay, sequestering variable amounts of thyroglobulin. The presence of these autoantibodies must be investigated prior to thyroglobulin determination.

Salt-wasting congenital adrenal hyperplasia: detection of mutations in CYP21B gene in a Chilean population.

The steroid 21-hydroxylase deficiency (21OHD) is the most frequent cause of congenital adrenal hyperplasia. We have characterized the disease-causing mutations in the 21-hydroxylase genes of 63 patients with salt-wasting congenital adrenal hyperplasia from a Chilean population of Hispanic origin, a group that has been scarcely evaluated. Using allele-specific PCR, lesions were identified in 97 chromosomes out of 126 tested (77%). The most frequent findings were the gene deletion or large gene conversion (LGC) = 22.9%, I2 splice = 19%, R357W = 12.7%, and Q319X = 10.5%. We did not find alleles with the mutation F308insT and we found three alleles with the cluster E6. The frequency of the point mutation R357W was at least two times more frequent than the one found in Caucasians populations, but similar to that communicated in Asian populations; this finding may be explained by the Asian ancestry of our South-Amerindian population. The frequency of Q319X was also high, similar only to those patients studied in Italy and in a neighboring Argentinian population. In summary, this is a genetic characterization of 21OHD made in an almost pure Hispanic population in Latin America. The high frequency of deletion of CYP21B gene, I2 splice, R357W, and Q319X mutations probably reflects the European-Caucasian-Spanish influence of the conquerors, mixed with Amerindians of Asian ancestry and modulated by other European immigrations.

[Molecular diagnosis of salt wasting congenital adrenal hyperplasia, caused by deficit of 21-hydroxylase, in the Chilean population]. / Diagnóstico molecular de hiperplasia suprarrenal congénita por déficit de 21-hidroxilasa, variedad perdedora de sal, en población chilena.

BACKGROUND: The most frequent cause of congenital adrenal hyperplasia, manifested as virilization and salt wasting, is the deficit of 21-hydroxylase. This disease is originated by mutations of the gene CYP21 that codifies this enzyme, mostly recombination between this gene and its inactive pseudogene called CYP21P. AIM: To study the molecular origin of this enzyme deficiency in Chilean patients. PATIENTS AND METHODS: Twenty five patients with salt wasting congenital adrenal hyperplasia, that had 17-hydroxyprogesterone levels above 30 ng/ml, were studied. In all patients, a polymerase chain reaction (PCR) with selective primers was done with extracted genomic DNA, to amplify the active gene and specific primers for normal or mutated alleles (Allele-specific PCR). RESULTS: The affected allele was identified in 39 (78%) of the 50 chromosomes of the 25 patients. The higher frequency affected the ASIn2 in 26% of cases, followed by mutations Arg357Trp in 22% of cases and Gln319Stop in 12% and deletion in 12%. The identification of two affected alleles in a same patient was achieved in 17 cases (68%). The most frequent genotypes were homozygosity for ASIn2 (16%), homozygosity for Arg357Trp (12%) and the homozygote deletion of the gene in 12%. CONCLUSION: The most frequent mechanisms of genetic damage in this population of patients with salt wasting congenital adrenal hyperplasia due to deficiency of 21-hydroxylase were the mutations ASIn2 and Arg357Trp. This type of studies allows prenatal diagnosis and genetic counseling.