Patterns of red blood cell utilization: Harnessing electronic health records data from the Information Standard for Blood and Transplant (ISBT) 128 system within the Biologics Effectiveness and Safety (BEST) initiative.

BACKGROUND: Current hemovigilance methods generally rely on survey data or administrative claims data utilizing billing and revenue codes, each of which has limitations. We used electronic health records (EHR) linked to blood bank data to comprehensively characterize red blood cell (RBC) utilization patterns and trends in three healthcare systems participating in the U.S. Food and Drug Administration Center for Biologics Evaluation and Research Biologics Effectiveness and Safety (BEST) initiative. METHODS: We used Information Standard for Blood and Transplant (ISBT) 128 codes linked to EHR from three healthcare systems data sources to identify and quantify RBC-transfused individuals, RBC transfusion episodes, transfused RBC units, and processing methods per year during 2012-2018. RESULTS: There were 577,822 RBC units transfused among 112,705 patients comprising 345,373 transfusion episodes between 2012 and 2018. Utilization in terms of RBC units and patients increased slightly in one and decreased slightly in the other two healthcare facilities. About 90% of RBC-transfused patients had 1 (~46%) or 2-5 (~42%)transfusion episodes in 2018. Among the small proportion of patients with ≥12 transfusion episodes per year, approximately 60% of episodes included only one RBC unit. All facilities used leukocyte-reduced RBCs during the study period whereas irradiated RBC utilization patterns differed across facilities. DISCUSSION: ISBT 128 codes and EHRs were used to observe patterns of RBC transfusion and modification methods at the unit level and patient level in three healthcare systems participating in the BEST initiative. This study shows that the ISBT 128 coding system in an EHR environment provides a feasible source for hemovigilance activities.

ABO Blood Groups Are Not Associated With COVID-19 Disease Incidence and Severity When Correcting for Ethnicity Differences in Blood Type.

OBJECTIVES: To determine if blood type is a risk factor for coronavirus disease 2019 (COVID-19) disease incidence and severity after correcting for ethnicity differences between novel infections and known ABO blood type frequency differences. METHODS: We performed a retrospective analysis on all severe acute respiratory system coronavirus 2 (SARS-CoV-2) infections and disease severity across two major testing sites in Colorado. We evaluated all individuals with a SARS-CoV-2 nucleic acid test (NAT) and a known blood type between March 1, 2020, and June 1, 2020. We then created a prediction algorithm based on the corrected blood types by ethnicity using data from the Colorado Department of Health and established blood types by ethnicity. We applied this prediction algorithm to all patients in our sample. RESULTS: Of 8,676 patients, 485 (5.6%) had a positive SARS-CoV-2 NAT test and 8,191 (94.4%) had a negative test. All patients had ABO blood types that mirrored the expected blood type distribution within the state of Colorado (P = .15, χ 2 statistic = 5.31). No differences in expected blood groups were present between ethnicity-adjusted SARS-CoV-2-negative and SARS-CoV-2-positive patients (χ 2 = 3.416313, P = .332). CONCLUSIONS: Blood type is not associated with COVID-19 disease incidence or severity after correcting for ethnicity differences in expected blood type frequencies.

Heterogeneity in Approaches for Switching From Universal to Patient ABO Type-Specific Blood Components During Massive Hemorrhage.

CONTEXT.­: ABO mistransfusions are rare and potentially fatal events. Protocols are required by regulatory agencies to minimize this risk to patients, but how these are applied in the context of massive transfusion protocols (MTPs) is not specifically defined. OBJECTIVE.­: To evaluate the approaches used by transfusion services for switching from universally compatible to patient ABO type-specific blood components during massive hemorrhage. DESIGN.­: We added 1 supplemental multiple-choice question to address the study objective to the 2019 College of American Pathologists proficiency test J-survey (J-A 2019). We also reviewed the available literature regarding this topic. RESULTS.­: A total of 881 laboratories responded to the supplemental question. Approximately 80% (704 of 881) reported a policy for ABO-type switching during an MTP. Policies varied considerably between responding laboratories, but most (384 of 704, 55%) required 2 ABO types to match before switching from universal to recipient-specific blood components. Additional safety measures used in a minority of these protocols included reaction strength criteria (103 of 704, 15%), on-call medical director approval (41 0f 704, 5.8%), universal red cell unit number limits (12 of 704, 1.7%), or the presence of a mixed field (3 of 704, 0.4%). CONCLUSIONS.­: This survey reveals that significant heterogeneity exists regarding the available approaches for ABO-type switching during an MTP. Specific expert guidance regarding this issue is very limited, and best practices have not yet been established or rigorously investigated.

Blood type change identifies late dominance reversal of chimerism after double umbilical cord blood transplantation with review of the literature.

BACKGROUND: A 30-year-old man underwent double umbilical cord blood transplantation (UCBT) for acute myeloid leukemia (AML) with reduced intensity conditioning. The cords had identical HLA types and were each a 5/6 match to the patient. Following transplantation, cord 2 initially dominated all tested cell populations. At day +306, we observed an unusual reversal of dominance chimerism pattern in which cord 1 instead dominated all tested populations. STUDY DESIGN & METHODS: Polymerase chain reaction (PCR)-based short tandem repeat (STR) assays were performed on the peripheral blood and bone marrow samples. The white blood cell (WBC) populations from the peripheral blood were manipulated for testing to create subpopulations enriched for CD3, CD33, and CD56. RESULTS: Chimerism studies on day +77 showed the following: cord 1: 44%-CD3; 0%-CD33; 16%-CD56; cord 2: 56%-CD3; 100%-CD33; 84%-CD56. Cord 2 initially dominated in all tested cell populations. Chimerism studies performed on post-transplantation day +306 uncovered a reversal of dominance chimerism pattern in which cord 1 now dominated in all cell populations (cord 1: 82%-CD3; >95%-CD33; 67%-CD56; cord 2: 18%-CD3; <5%-CD33; 33%-CD56). Between days +127 and +244, the patient's blood type shifted from B Rh-positive to A Rh-negative. CONCLUSION: The change in the patient's blood type identified a late reversal of dominance chimerism pattern. This is a rare occurrence, previously cited only once, which is inconsistent with published data that early high CD3 counts and unseparated bone marrow chimerism predominance at day +100 predict long-term cord dominance in double UCBT in the vast majority of cases.

The Crossmatch/Issue Ratio: Use of a Novel Quality Indicator and Results of an International Survey on RBC Crossmatching and Issuing Practices.

OBJECTIVES: To understand the worldwide scope of RBC crossmatching and issuing practices and measure efficiency using a novel quality indicator, the crossmatch/issue (C/I) ratio. METHODS: An electronic survey was disseminated to hospital transfusion services collecting details about RBC crossmatching and issuing practices. Respondents were asked to enumerate the number of RBCs crossmatched and issued at their institutions during the 2014 calendar year to calculate the C/I ratio. RESULTS: Fifty-two survey responses were received, mostly from North American transfusion services (28/52, 54%). The electronic crossmatch was the most common technique (n = 29), and most respondents performed the crossmatch at the time that an order for RBCs was received in the transfusion service (even if an order to issue the RBCs was not received). Data to calculate the C/I ratio were supplied by 22 respondents, and the mean ± SD was 1.30 ± 0.34. There was no difference in C/I ratios between services that use the electronic or serologic crossmatch techniques (P = .49). The ratio was the same at the four sites that crossmatch RBCs at the time of issue compared with the time of order receipt (mean ± SD, 1.11 ± 0.09 vs. 1.35 ± 0.36, respectively; P = .19). CONCLUSIONS: Electronic crossmatching is common, and the C/I ratio can be an indicator of efficiency.

The role of lipoprotein(a) in clotting reactions during lipoprotein apheresis--A case report.

In individuals with familial hypercholesterolemia (FH) who are unable to reach a target low-density lipoprotein level on a drug regimen, lipoprotein apheresis (LA) may be the treatment of choice. Severe reactions involving clotting during LA are not well described in the literature. We report a case of a 63-year-old woman with FH and markedly elevated lipoprotein(a) (Lp[a]) levels who experienced such a reaction while undergoing LA with a dextran-sulfate cellulose column on the Kaneka MA-01 Liposorber system. Owing to the clotting as well as a blood pressure drop to <100 mm Hg systolic, the procedure was stopped early. Before her second procedure, she was given an increased loading dose of unfractionated heparin. She did not develop clotting during this second procedure. A growing body of literature on the role of Lp(a) in atherothrombotic complications and hemostasis supports a possible mechanism by which clotting in the instrument could occur during apheresis. Our patient's initial pretreatment Lp(a) was 3.5 times greater than the mean Lp(a) levels in patients with FH. This theory is consistent with our case in that the patient's Lp(a) levels progressively declined with each procedure, and she had no subsequent clotting.

Venous access for hematopoietic progenitor cell collection: An international survey by the ASFA HPC donor subcommittee.

PURPOSE: Hematopoietic Progenitor Cell (HPC) collection by apheresis is performed in patients and donors to obtain HPCs for transplantation. Although studies have shown these procedures to be safe, successful collection cannot be performed without establishment of venous access. This project's objective was to ascertain the current practices of donor vein assessment and central venous catheter (CVC) usage. METHODS: The American Society for Apheresis (ASFA) HPC subcommittee created an electronic survey about precollection vein assessment and line placement, care, and removal in autologous and allogeneic donors. It was distributed to >5,000 possible participants, with one response analyzed per institution. RESULTS: One hundred centers performing autologous and/or allogeneic procedures provided adequate responses for analysis. Donor vein assessment is most often performed by apheresis staff more than 1 week prior to collection. For patients with questionable access, the next step performed most often is secondary assessment for autologous procedures and CVC placement for allogeneic procedures. Most centers use interventional radiology to place CVCs in jugular veins on collection day with placement verification through electronic medical records. Verbal and written postinsertion CVC care instructions are routinely provided. The apheresis team frequently provides postinsertion CVC care for autologous patients. Heparin is used most often for CVC lock. When used, tissue plasminogen activator is usually instilled for up to 60 min. CONCLUSION: These data summarize the largest single survey of donor vein assessment at institutions performing HPC collections by apheresis. The variations identified in donor venous access practice warrant further investigation and consensus to establish best practices. J. Clin. Apheresis 31:529-534, 2016. © 2015 Wiley Periodicals, Inc.

Preventing hypothermia in elective arthroscopic shoulder surgery patients: a protocol for a randomised controlled trial.

BACKGROUND: Patients having arthroscopic shoulder surgery frequently experience periods of inadvertent hypothermia. This common perioperative problem has been linked to adverse patient outcomes such as myocardial ischaemia, surgical site infection and coagulopathy. International perioperative guidelines recommend patient warming, using a forced air warming device, and the use of warmed intraoperative irrigation solutions for the prevention of hypothermia in at-risk patient groups. This trial will investigate the effect of these interventions on patients' temperature, thermal comfort, and total recovery time. METHOD/DESIGN: The trial will employ a randomised 2 x 2 factorial design. Eligible patients will be stratified by anaesthetist and block randomised into one of four groups: Group one will receive preoperative warming with a forced air warming device; group two will receive warmed intraoperative irrigation solutions; group three will receive both preoperative warming and warmed intraoperative irrigation solutions; and group four will receive neither intervention. Participants in all four groups will receive active intraoperative warming with a forced air warming device. The primary outcome measures are postoperative temperature, thermal comfort, and total recovery time. Primary outcomes will undergo a two-way analysis of variance controlling for covariants such as operating room ambient temperature and volume of intraoperative irrigation solution. DISCUSSION: This trial is designed to confirm the effectiveness of these interventions at maintaining perioperative normothermia and to evaluate if this translates into improved patient outcomes. AUSTRALIAN NEW ZEALAND CLINICAL TRIALS REGISTRY NUMBER: ACTRN12610000591055.

Preventing inadvertent hypothermia: comparing two protocols for preoperative forced-air warming.

Preoperative forced-air warming is one way of preventing inadvertent perioperative hypothermia. There is scant evidence, however, on the best warming method or the acceptability of these methods to patients. This pilot study compared two warming protocols: one that commenced at maximum temperature and was titrated down as requested (A) and one that commenced at near body temperature and was titrated up as tolerated (B). A crossover design was used in which each participant (n=10) received both protocols sequentially. The mean device temperature and length of time spent at maximum settings were greater for protocol A (43°C±0°C vs 41°C±1°C, P=.003; and 60±0 vs 41.5±2.8 minutes, P=.004). There was no difference in thermal comfort scores, participant temperature, or sweating between the two protocols. When asked, participants preferred protocol A to B (70% to 30%). Starting at higher device settings appears the more favorable of the two approaches.

Colonic angiolymphoid hyperplasia with eosinophilia masquerading as malignancy: a case report and review of the literature.

Angiolymphoid hyperplasia with eosinophilia (AHE) of the colon is a rare entity. Since 1997, to our knowledge only 2 similar cases have been documented in the literature. Here, we report a third case that presented as a transverse colonic mass mimicking cancer both clinically and radiologically. Microscopically classic morphologic criteria of this entity were observed, which consisted of both a vascular proliferation and an inflammatory component rich in eosinophils without any malignant features. Whether AHE is a reactive process or a neoplastic process (either a benign vascular neoplasm or a T-cell lymphoproliferative disorder) is still under debate. However, it is important to recognize this entity as a cause of colonic mass to avoid a misdiagnosis of malignancy.

Increased cyclin D3 expression significantly correlates with p27 nuclear positivity in gastrointestinal stromal tumors.

Gastrointestinal stromal tumors, the most common mesenchymal tumors of the gastrointestinal tract, are characterized by strong expression of c-Kit protein. Recently, it has been shown that gastrointestinal stromal tumors may also contain alterations of genes involved in the regulation of cell cycle. In this study, we evaluate the prevalence and clinical significance of cyclin D1 and D3, Ki-67, p27, and retinoblastoma protein expression in a group of 50 human gastrointestinal stromal tumors selected from the files of the Moffitt Cancer Center. Tissue sections from each case were subjected to immunostaining using the avidin-biotin complex method. Cyclin D1 nuclear positivity was detected in 21 of 50 (42%) and cyclin D3 in 24 of 50 (48%) cases. p27 high immunoreactivity and negative or decreased retinoblastoma protein expression were identified in 33 of 50 (66%) gastrointestinal stromal tumors. In 19 of 50 (38%) tumors, Ki-67 had high labeling index. Direct correlation was observed between cyclin D3 and p27 expression (P < .0001), and between cyclin D1 and retinoblastoma protein (P = .03). Coexpression of cyclin D3 and p27 was demonstrated by immunofluorescence. The p27 protein expression inversely correlated with tumor size (P = .004), but was not correlated with tumor grade (P = .12). Ki-67 directly correlated with both tumor size (P = .03) and tumor grade (P = .008). We report a direct correlation between cyclin D3 and p27 expression in gastrointestinal stromal tumors. Additional alterations in cyclin D1, Ki-67, and retinoblastoma protein expression indicate a disregulated cell cycle in these tumors.

Dispermic chimerism identified during HLA typing for stem cell transplantation.

BACKGROUND: Chimerism is defined as the presence of two genetically distinct cell populations in an organism. Few cases of phenotypically normal dispermic chimeras have been reported and most showed abnormalities on blood typing. CASE REPORT: A 32-year-old man was diagnosed with acute myelomonocytic leukemia. He clearly typed as group A, D-. No abnormalities of sexual development were identified on multiple physical exams, previous exploratory surgery, or CT scans. Molecular HLA typing (sequence-specific primers) in preparation for stem cell transplant showed the patient to have three HLA-B* and three HLA-Cw* alleles. Initial serologic HLA typing reported two haplotypes, but on subsequent review reactions for a third HLA-B antigen that were initially deemed to be false-positive reactions were identified. Two of 10 microsatellite short tandem repeat (STR) loci also showed three distinct alleles in blood and buccal samples. In all studies the third allele was attributable to a dual paternal contribution. CONCLUSION: This case represents dispermic chimerism, with one maternal and two paternal haplotypes variably distributed throughout body tissues in a phenotypically normal man without abnormalities in blood typing. The presence of additional alleles that may have been undetected or dismissed by serologic typing should be carefully investigated and verified by molecular techniques. Molecular HLA typing may increase the accurate identification of phenotypically normal chimeras and aid in selecting proper donors for transplantation to reduce graft-versus-host disease and transplant rejection in these patients.

Identification of SNPs, or mutations in sequence chromatograms.

With the completion of the human genome sequencing project in 2001, the identification of novel markers is rapidly gaining importance. It is increasingly recognized that SNPs (single nucleotide polymorphisms) are good markers for disease susceptibility. SNPs are DNA sequence variations that occur when a single nucleotide in the genome sequence is altered in at least 1 % of the population. SNPs may have no effect on cell function, but scientists believe that they could predispose people to disease or influence their response to a drug. This chapter describes the method of using fluorescent based sequencing to detect SNPs and mutations. Sequencing provides information on the type and location of the SNPs with high accuracy. Researchers will need to provide information on the area of the genome they wish to sequence to design primers to PCR amplify the specific region.

Dermatologic perivascular hemophagocytosis: a report of two cases.

Hemophagocytic syndrome includes fever, hepatosplenomegaly, cytopenias, coagulopathy, and abnormal liver function tests, with some patients developing lymphadenopathy and cutaneous eruptions. Herein we report two cases of dermal perivascular hemophagocytosis identified in skin biopsies of two patients with no additional symptoms attributable to hemophagocytic syndrome. Biopsies showed capillary ectasia with dermal perivascular infiltrates. The overlying epidermis and adjacent subcutaneous fat was unremarkable. The infiltrate consisted of perivascular neutrophils and benign histiocytes with predominately phagocytized erythrocytes and occasional engulfed karyorrhectic debris. Perivascular nuclear dust (leukocytoclasia) and extravasated erythrocytes were present, but other factors typically found in leukocytoclastic vasculitis were absent, namely fibrin deposition and endothelial hypertrophy and/or necrosis. This appears to be hemophagocytosis, possibly associated with late lesions of leukocytoclastic vasculitis. Both hemophagocytosis and leukocytoclastic vasculitis are associated with activated immunity with increased cytokines and/or immune complexes. It is important to consider this uncommon finding in the evaluation of indeterminate cutaneous eruptions.

Variants implicated in cortisone reductase deficiency do not contribute to susceptibility to common forms of polycystic ovary syndrome.

OBJECTIVE: There are close phenotypic similarities between cortisone reductase deficiency (CRD), a rare abnormality of cortisone metabolism, and polycystic ovary syndrome (PCOS). As there is evidence that CRD results from digenic mutations involving the genes encoding 11beta-hydroxysteroid dehydrogenase type 1 (HSD11B1) and hexose-6-phosphate dehydrogenase (H6PD), we sought to establish whether CRD-associated variants in these genes, individually or in combination, influence susceptibility to PCOS. DESIGN: Case-control, family-based association and quantitative-trait analyses. PATIENTS: A UK case sample comprising 256 nuclear families ascertained from a PCOS offspring and 213 singleton PCOS cases plus 549 control subjects. MEASUREMENTS: All subjects were genotyped for CRD-related variants in HSD11B1 (rs12086634) and H6PD (rs6688832). Testosterone was measured with an in-house radioimmunoassay using ether extraction and dextran-coated charcoal separation. RESULTS: Case-control analyses revealed no differences in genotype distribution between PCOS and controls for rs12086634 or rs6688832 (both P = 0.84). Three per cent of cases and 2.4% of controls had genotype combinations (three or more variant alleles at the two sites) considered characteristic of CRD (P = 0.73). There were no departures from expectation in the family-based association studies, and no significant associations between genotypes (individually or in combination) and BMI, WHR or testosterone. CONCLUSIONS: The variants in HSD11B1 and H6PD typed, though implicated in causation of CRD, do not influence susceptibility to PCOS. It seems likely that additional variants within these genes are required for the development of CRD.

Hexose-6-phosphate dehydrogenase knock-out mice lack 11 beta-hydroxysteroid dehydrogenase type 1-mediated glucocorticoid generation.

The local generation of active glucocorticoid by NADPH-dependent, 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) oxoreductase activity, has emerged as an important factor in regulating hepatic glucose output and visceral adiposity. We have proposed that this NADPH is generated within the endoplasmic reticulum by the enzyme hexose-6-phosphate dehydrogenase. To address this hypothesis, we generated mice with a targeted inactivation of the H6PD gene. These mice were unable to convert 11-dehydrocorticosterone (11-DHC) to corticosterone but demonstrated increased corticosterone to 11-DHC conversion consistent with lack of 11beta-HSD1 oxoreductase and a concomitant increase in dehydrogenase activity. This increased corticosterone clearance in the knock-out mice resulted in a reduction in circulating corticosterone levels. Our studies define the critical requirement of hexose-6-phosphate dehydrogenase for 11beta-HSD1 oxoreductase activity and add a new dimension to the investigation of 11beta-HSD1 as a therapeutic target in patients with the metabolic syndrome.

11beta-hydroxysteroid dehydrogenase and the pre-receptor regulation of corticosteroid hormone action.

Two isozymes of 11beta-hydroxysteroid dehydrogenase (11beta-HSD1 and 11beta-HSD2) catalyse the interconversion of hormonally active cortisol and inactive cortisone. The enzyme evolved from a metabolic pathway to a novel mechanism underpinning human disease with the elucidation of the role of the type 2 or 'kidney' isozyme and an inherited form of hypertension, 'apparent mineralocorticoid excess'. 'Cushing's disease of the kidney' arises because of a failure of 11beta-HSD2 to inactivate cortisol to cortisone resulting in cortisol-induced mineralocorticoid excess.Conversely, 11beta-HSD1 has been linked to human obesity and insulin resistance, but also to other diseases in which glucocorticoids have historically been implicated (osteoporosis, glaucoma). Here, the activation of cortisol from cortisone facilitates glucocorticoid hormone action at an autocrine level. The molecular basis for the putative human 11beta-HSD1 'knockout'--'cortisone reductase deficiency'--has recently been described, an observation that also answers a long standing conundrum relating to the set-point of 11beta-HSD1 activity. In each case, these clinical studies have been underpinned by studies in vitro and the manipulation of enzyme expression in vivo using recombinant mouse models.

Hexose-6-phosphate dehydrogenase confers oxo-reductase activity upon 11 beta-hydroxysteroid dehydrogenase type 1.

Two isozymes of 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) interconvert active cortisol and inactive cortisone. 11 beta-HSD2 (renal) acts only as a dehydrogenase, converting cortisol to cortisone. 11 beta-HSD1 (liver) is a bi-directional enzyme in cell homogenates, whereas in intact cells it typically displays oxo-reductase activity, generating cortisol from cortisone. We recently established that cortisone reductase deficiency is a digenic disease requiring mutations in both the gene encoding 11 beta-HSD1 and in the gene for a novel enzyme located within the lumen of the endoplasmic reticulum (ER), hexose-6-phosphate dehydrogenase (H6PDH). This latter enzyme generates NADPH, the co-factor required for oxo-reductase activity. Therefore, we hypothesized that H6PDH expression may be an important determinant of 11 beta-HSD1 oxo-reductase activity. Transient transfection of chinese hamster ovary (CHO) cells with 11 beta-HSD1 resulted in the appearance of both oxo-reductase and dehydrogenase activities in intact cells. Co-transfection of 11 beta-HSD1 with H6PDH increased oxo-reductase activity whilst virtually eliminating dehydrogenase activity. In contrast, H6PDH had no effect on reaction direction of 11 beta-HSD2, nor did the cytosolic enzyme, glucose-6-phosphate dehydrogenase (G6PD) affect 11 beta-HSD1 oxo-reductase activity. Conversely in HEK 293 cells stably transfected with 11 beta-HSD1 cDNA, transfection of an H6PDH siRNA reduced 11 beta-HSD1 oxo-reductase activity whilst simultaneously increasing 11 beta-HSD1 dehydrogenase activity. In human omental preadipocytes obtained from 15 females of variable body mass index (BMI), H6PDH mRNA levels positively correlated with 11 beta-HSD1 oxo-reductase activity, independent of 11 beta-HSD1 mRNA levels. H6PDH expression increased 5.3-fold across adipocyte differentiation (P < 0.05) and was associated with a switch from 11 beta-HSD1 dehydrogenase to oxo-reductase activity. In conclusion, H6PDH is a crucial determinant of 11 beta-HSD1 oxo-reductase activity in intact cells. Through its interaction with 11 beta-HSD1, H6PDH may represent a novel target in the pathogenesis and treatment of obesity.

11beta-hydroxysteroid dehydrogenase type 1: a tissue-specific regulator of glucocorticoid response.

11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) interconverts inactive cortisone and active cortisol. Although bidirectional, in vivo it is believed to function as a reductase generating active glucocorticoid at a prereceptor level, enhancing glucocorticoid receptor activation. In this review, we discuss both the genetic and enzymatic characterization of 11beta-HSD1, as well as describing its role in physiology and pathology in a tissue-specific manner. The molecular basis of cortisone reductase deficiency, the putative "11beta-HSD1 knockout state" in humans, has been defined and is caused by intronic mutations in HSD11B1 that decrease gene transcription together with mutations in hexose-6-phosphate dehydrogenase, an endoluminal enzyme that provides reduced nicotinamide-adenine dinucleotide phosphate as cofactor to 11beta-HSD1 to permit reductase activity. We speculate that hexose-6-phosphate dehydrogenase activity and therefore reduced nicotinamide-adenine dinucleotide phosphate supply may be crucial in determining the directionality of 11beta-HSD1 activity. Therapeutic inhibition of 11beta-HSD1 reductase activity in patients with obesity and the metabolic syndrome, as well as in glaucoma and osteoporosis, remains an exciting prospect.

Congenital adrenal hyperplasia caused by mutant P450 oxidoreductase and human androgen synthesis: analytical study.

BACKGROUND: Congenital adrenal hyperplasia with apparent combined P450C17 and P450C21 deficiency is associated with accumulation of steroid metabolites, indicating impaired activity of 17alpha-hydroxylase and 21-hydroxylase. However, no mutations have been reported in the CYP17 and CYP21 genes, which encode these P450 enzymes. Affected girls are born with ambiguous genitalia, but their circulating androgens are low, and virilisation does not progress. We aimed to investigate the underlying molecular basis of congenital adrenal hyperplasia with apparent combined P450C17 and P450C21 deficiency in affected children. METHODS: We did sequence analysis of the human gene encoding P450 oxidoreductase, an enzyme that is important in electron transfer from NADPH to P450C17 and P450C21. We studied two unrelated families with a total of three affected children and 100 healthy controls. Wild-type and mutant P450 oxidoreductase proteins were bacterially expressed, purified, and assayed for cytochrome c reductase activity. FINDINGS: We identified four mutations encoding single aminoacid changes in P450 oxidoreductase. All patients were compound heterozygotes, whereas their parents and an unaffected sibling harboured a mutation in only one allele. By contrast, no mutations were noted in the controls. Bacterial expression of recombinant mutant proteins revealed deficient or reduced enzyme activity. INTERPRETATION: Molecular pathogenesis of this form of congenital adrenal hyperplasia is caused by mutations in the gene encoding P450 oxidoreductase. Deficiency of this enzyme could suggest an alternative pathway in human androgen synthesis, present only in fetal life, which explains the combination of antenatal androgen excess and postnatal androgen deficiency.