Sex Hormone Binding Globulin Deficiency Due to a Homozygous Missense Mutation

Context: SHBG is known as the major sex steroid binding protein in plasma, and it regulates the bioavailability of both T and estradiol levels required for effects on target tissues. We identified a man with an undetectable SHBG concentration in combination with low total T. He presented with a 7-year history of muscle weakness, fatigue, and a low libido. Objectives: To determine the cause of the SHBG deficiency, we employed both genetic analysis of the SHBG gene and transgene SHBG expression. Results: Genetic analysis identified a novel homozygous missense mutation that was predicted to be deleterious for protein function. Transgene expression showed that the mutation resulted in a block in SHBG secretion accompanied by increased expression of the endoplasmic reticulum molecular chaperone HSPA5. The mutation results in accumulation of the mutant SHBG within the cell and failure to secrete the mutant protein. Screening of family members identified one sister who was also deficient for SHBG. Conclusions: We have identified a family with a missense mutation within the SHBG gene, which results in a complete deficiency of plasma SHBG in the homozygous state. Although total T level was low in the male patient, it did not interfere with normal gonadal development and spermatogenesis, suggesting a limited role of SHBG in sexual maturation and male physiology

Clinical characteristics of women captured by extending the definition of severe postpartum haemorrhage with 'refractoriness to treatment': a cohort study

Background: The absence of a uniform and clinically relevant definition of severe postpartum haemorrhage hampers comparative studies and optimization of clinical management. The concept of persistent postpartum haemorrhage, based on refractoriness to initial first-line treatment, was proposed as an alternative to common definitions that are either based on estimations of blood loss or transfused units of packed red blood cells (RBC). We compared characteristics and outcomes of women with severe postpartum haemorrhage captured by these three types of definitions. Methods: In this large retrospective cohort study in 61 hospitals in the Netherlands we included 1391 consecutive women with postpartum haemorrhage who received either ≥4 units of RBC or a multicomponent transfusion. Clinical characteristics and outcomes of women with severe postpartum haemorrhage defined as persistent postpartum haemorrhage were compared to definitions based on estimated blood loss or transfused units of RBC within 24 h following birth. Adverse maternal outcome was a composite of maternal mortality, hysterectomy, arterial embolisation and intensive care unit admission. Results: One thousand two hundred sixty out of 1391 women (90.6%) with postpartum haemorrhage fulfilled the definition of persistent postpartum haemorrhage. The majority, 820/1260 (65.1%), fulfilled this definition within 1 h following birth, compared to 819/1391 (58.7%) applying the definition of ≥1 L blood loss and 37/845 (4.4%) applying the definition of ≥4 units of RBC. The definition persistent postpartum haemorrhage captured 430/471 adverse maternal outcomes (91.3%), compared to 471/471 (100%) for ≥1 L blood loss and 383/471 (81.3%) for ≥4 units of RBC. Persistent postpartum haemorrhage did not capture all adverse outcomes because of missing data on timing of initial, first-line treatment. Conclusion: The definition persistent postpartum haemo

Validation of the I mu g short synacthen test:An assessment of morning cortisol cut-off values and other predictors

Background: Clinical practice shows that many low-dose short synacthen tests (LD-SSTs) for diagnosing adrenal insufficiency in an outpatient setting have a normal outcome and could be considered superfluous. The objective of this study is to provide a guideline to safely reduce the number of unnecessarily performed LD-SSTs. Methods: Data of LD-SSTs performed in outpatients were collected. Optimal morning cortisol cut-off values were determined using ROC analysis. Subsequently the predictive value of several variables was tested using univariable and multivariable logistic regression analyses. Results: A morning cortisol lower cut-off value of 145 nmol/l (specificity 89.9%, positive predictive value 90.0%) and an upper cut-off value of 375 nmol/l (sensitivity 100.0%, negative predictive value 100.0%) were found. Chronic fatigue symptoms and symptoms of hypotension or orthostasis as the main reason for performing the test predict a normal outcome. The use of glucocorticosteroids predicts an abnormal outcome of the LD-SST. Oral, topical, nasal and inhaled glucocorticosteroids are each significant predictors when analysed specifically for predicting central adrenal insufficiency. Conclusion: By using morning cortisol cut-off values of 145 nmol/l and 375 nmol/l instead of the conventional cut-off values, the number of LD-SSTs performed in an outpatient setting can be reduced by 12%, while maintaining high sensitivity and specificity. Furthermore, the outcome of the LD-SST can be predicted by additional variables such as the indication for performing the test and the use of glucocorticosteroids. Different routes of administration of glucocorticosteroids such as inhalation or topical use should be taken into account when central insufficiency is suspected

Validation of multisource electronic health record data : An application to blood transfusion data

Background: Although data from electronic health records (EHR) are often used for research purposes, systematic validation of these data prior to their use is not standard practice. Existing validation frameworks discuss validity concepts without translating these into practical implementation steps or addressing the potential influence of linking multiple sources. Therefore we developed a practical approach for validating routinely collected data from multiple sources and to apply it to a blood transfusion data warehouse to evaluate the usability in practice. Methods: The approach consists of identifying existing validation frameworks for EHR data or linked data, selecting validity concepts from these frameworks and establishing quantifiable validity outcomes for each concept. The approach distinguishes external validation concepts (e.g. concordance with external reports, previous literature and expert feedback) and internal consistency concepts which use expected associations within the dataset itself (e.g. completeness, uniformity and plausibility). In an example case, the selected concepts were applied to a transfusion dataset and specified in more detail. Results: Application of the approach to a transfusion dataset resulted in a structured overview of data validity aspects. This allowed improvement of these aspects through further processing of the data and in some cases adjustment of the data extraction. For example, the proportion of transfused products that could not be linked to the corresponding issued products initially was 2.2% but could be improved by adjusting data extraction criteria to 0.17%. Conclusions: This stepwise approach for validating linked multisource data provides a basis for evaluating data quality and enhancing interpretation. When the process of data validation is adopted more broadly, this contributes to increased transparency and greater reliability of research based on routinely collected electronic health records

Neonatal screening for medium-chain acyl-CoA dehydrogenase (MCAD) deficiency in The Netherlands: The importance of enzyme analysis to ascertain true MCAD deficiency

The outcome was determined of population-wide neonatal screening for medium-chain acyl-CoA dehydrogenase (MCAD) deficiency using tandem mass spectrometry (MS/MS) in The Netherlands, between October 2003 and September 2005. Prospective population-wide neonatal screening for MCAD deficiency was performed in the northern part of The Netherlands. In newborns with blood octanoylcarnitine (C-8:0) concentrations >= 0.3 mu mol/L, clinical and laboratory follow-up was initiated, including MCAD enzymatic measurements which played a decisive role. In a 2-year period, 66 216 newborns were investigated for MCAD deficiency and follow-up was initiated in 28 newborns. True-positives (n=14) were identified based upon MCAD enzyme activity 5.0 turned out to differentiate between false-positives and true-positives. Measurement of MCAD activity using phenylpropionyl-CoA as a substrate further discriminated between newborns with MCAD deficiency and so-called mild MCAD deficiency. To summarize, neonatal screening for MCAD deficiency in the northern part of The Netherlands resulted in the predicted number of affected newborns. Measurement of MCAD activity in leukocytes or lymphocytes using phenylpropionyl-CoA as a substrate can be regarded as the gold standard to diagnose MCAD deficiency upon initial positive screening test results

Age of platelet concentrates and time to the next transfusion

BACKGROUND: Storage time of platelet (PLT) concentrates has been negatively associated with clinical efficacy outcomes. The aim of this study was to quantify the association between storage time of PLT concentrates and interval to the next PLT transfusion for different types of PLT components, stored for up to 7 days and transfused to transfusion-dependent hematooncology patients with thrombocytopenia. STUDY DESIGN AND METHODS: From a cohort of patients from 10 major Dutch hospitals, patients were selected whose transfusion patterns were compatible with PLT transfusion dependency due to hematooncologic disease. Mean time to the next transfusion and mean differences in time to the next transfusion for different storage time categories (i.e., fresh, <4 days; intermediate, 4-5 days; and old, >5 days) were estimated, per component type, using multilevel mixed-effects linear models. RESULTS: Among a cohort of 29,761 patients who received 140,896 PLT transfusions we selected 4441 hematooncology patients who had received 12,724 PLT transfusions during periods of PLT transfusion dependency. Transfusion of fresh, compared to old, buffy coat–derived PLTs in plasma was associated with a delay to the next transfusion of 6.2 hours (95% confidence interval [CI], 4.5-8.0 hr). For buffy coat–derived PLTs in PAS-B and -C this difference was 7.7 hours (95% CI, 2.2-13.3 hr) and 3.9 hours (95% CI, –2.1 to 9.9 hr) while for apheresis PLTs in plasma it was only 1.8 hours (95% CI, –3.5 to 7.1 hr). CONCLUSION: Our results indicate that the time to the next transfusion shortens with increasing age of transfused buffy coat–derived PLT concentrates. This association was not observed for apheresis PLTs