An automated contact model for transmission of dry surface biofilms of Acinetobacter baumannii in healthcare

BACKGROUND

Dry surface biofilms (DSBs) have been recognized across environmental and equipment surfaces in hospitals and could explain how microbial contamination can survive for an extended period and may play a key role in the transmission of hospital-acquired infections. Despite little being known on how they form and proliferate in clinical settings, DSB models for disinfectant efficacy testing exist.

AIM

In this study we develop a novel biofilm model to represent formation within hospitals, by emulating patient to surface interactions.

METHODS

The model generates a DSB through the transmission of artificial human sweat (AHS) and clinically relevant pathogens using a synthetic thumb capable of emulating human contact. The DNA, glycoconjugates and protein composition of the model biofilm, along with structural features of the micro-colonies was determined using fluorescent stains visualized by epifluorescence microscopy and compared with published clinical data.

RESULTS

Micrographs revealed the heterogeneity of the biofilm across the surface; and reveal protein as the principal component within the matrix, followed by glycoconjugates and DNA. The model repeatably transferred trace amounts of micro-organisms and AHS, every 5 min for up to 120 h on to stainless-steel coupons to generate a biofilm model averaging 1.16 × 103 cfu/cm2 falling within the reported range for clinical DSB (4.20 × 102 to 1.60 × 107 bacteria/cm2).

CONCLUSION

Our in vitro DSB model exhibits many phenotypical characteristics and traits to those reported in situ. The model highlights key features often overlooked and the potential for downstream applications such as antibiofilm claims using more realistic microbial challenges.

P-590 Discriminatory value of steroid hormones on polycystic ovary syndrome in women with infertility and obesity

Study question

Which steroid hormone (ratio) has the highest discriminatory value in the biochemical diagnosis of polycystic ovary syndrome (PCOS) in women with infertility and obesity?

Summary answer

Androstenedione (A4) is a potentially useful discriminatory biomarker for PCOS in women with obesity, whereas Testosterone (T)/Dihydrotestosterone (DHT) and 11-oxygenated androgens are not.

What is known already

The best biomarker to assess biochemical hyperandrogenism in PCOS is still under discussion. Serum total or free T, followed by Free Androgen Index (FAI), and Dehydroepiandrosterone Sulfate (DHEA-S) are the most widely used biomarkers. T/DHT ratio has been proposed as a useful biomarker for PCOS. Moreover, a recent study demonstrated 11-oxygenated androgens represent the majority of circulating androgens in PCOS. Whether this is also relevant in women with obesity is unclear. We aimed to assess the discriminatory value of different steroid hormones and their ratios for PCOS as well as adverse metabolic phenotype within PCOS in women with obesity.

Study design, size, duration

We used the baseline data and samples originating from an RCT that examined whether a six-month lifestyle intervention prior infertility treatment in women with obesity improved live birth rate, compared to prompt infertility treatment. In total of 577 women with obesity were randomized between 2009 and 2012. Women were diagnosed with PCOS according to the Rotterdam criteria. Metabolic syndrome was diagnosed based on the revised criteria of the National Cholesterol Education Program.

Participants/materials, setting, methods

Women with PCOS comprised the study group (N = 132). Ovulatory women with idiopathic, tubal or male factor infertility were the control group (N = 83). Women were excluded when blood sampling was performed in the luteal phase or when baseline samples were unavailable. The steroid hormones were measured using LC-MS/MS. 11β-hydroxyandrostenedione (11OHA4) and 11-ketotestosterone (11KT) were analyzed using LC-MS/MS in a separate method. The discriminatory value was based on receiver operator characteristic (ROC) curves with adjustment for age.

Main results and the role of chance

The mean age was 28.1 years in the PCOS group and 30.9 years in the control group (p < 0.001). BMI was not significantly different (36.0±3.2 versus 35.7±3.5, p = 0.51). Among the tested steroid hormones (ratios), SHBG, A4, T, DHT, 11KT, FAI, T/DHT ratio, and T/A4 ratio showed statistically significant differences between the PCOS and the control group. DHEA, DHEA-S, 11OHA4 did not differ between the groups. The crude AUCs of FAI, T, A4, T/DHT ratio, SHBG, 11KT, T/A4 ratio, and DHT in ROC analysis for representing PCOS were 0.85, 0.84, 0.81, 0.70, 0.62, 0.59, 0.58, and 0.57 respectively. Among the markers with crude AUCs≥0.70, the incremental value of the marker A4 (AUC difference: 0.14, 95%CI: 0.07 to 0.21), T (0.18, 95%CI: 0.10 to 0.25), and FAI (0.18, 95%CI: 0.10 to 0.25) in addition to age showed significant improvement, but T/DHT ratio (0.02, 95%CI: –0.01 to 0.04) did not. However, the combination of A4 together with T or FAI did improve discriminatory value of individual T or FAI (AUC difference: –0.001, 95%CI: –0.004 to 0.003 and 0.007, –0.007 to 0.02, respectively). None of the measured steroid hormones (ratios) have promising discriminatory value for adverse metabolic phenotype within PCOS in women with obesity.

Limitations, reasons for caution

This is a post-hoc analysis and no power calculation was performed. There was a significant difference in age between women with and without PCOS, and residual confounding might exist. All PCOS patients in this analysis were infertile and obese, and it is conceivable that milder PCOS phenotypes are not represented.

Wider implications of the findings

T/DHT ratio and 11-oxygenated androgens might not serve as a promising discriminatory biomarker for PCOS in women with obesity, nor for adverse metabolic phenotype within PCOS in these women. A4 is a potential biomarker for PCOS diagnosis in women with infertility and obesity, however, its utility potency needs further validation.

Trial registration number

NTR 1530

Bioavailability of Oral Hydrocortisone Corrected for Binding Proteins and Measured by LC-MS/MS Using Serum Cortisol and Salivary Cortisone

Context

The assessment absolute bioavailability of oral hydrocortisone is complicated by its saturable binding to cortisol binding globulin (CBG). Previous assessment of bioavailability used a cortisol radioimmunoassay which has cross reactivity with other steroids. Salivary cortisone is a measure of free cortisol and LC-MS/MS is the gold standard method for measuring steroids. We here report the absolute bioavailability of hydrocortisone calculated using serum cortisol and salivary cortisone measured by LC-MS/MS.

Methods

14 healthy male dexamethasone suppressed volunteers were administered 20 mg hydrocortisone either intravenously or orally by tablet. Samples of serum and saliva were taken and measured for cortisol and cortisone by LC-MS/MS. Serum cortisol was corrected for saturable binding using published data and pharmacokinetic parameters derived using the program WinNonlin.

Results

The mean (95% CI) bioavailability of oral hydrocortisone calculated from serum cortisol, unbound serum cortisol and salivary cortisone was 1.00 (0.89-1.14); 0.88 (0.75-1.05); and 0.93 (0.83-1.05), respectively.

Conclusion

The data confirm that, after oral administration, hydrocortisone is completely absorbed. The data derived from serum cortisol corrected for protein binding, and that from salivary cortisone, are similar supporting the concept that salivary cortisone reflects serum free cortisol levels and that salivary cortisone can be used as a non-invasive method for measuring the pharmacokinetics of hydrocortisone.

High salivary testosterone-to-androstenedione ratio and adverse metabolic phenotypes in women with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is characterized by a combination of hormonal and metabolic disturbances, such as insulin resistance, glucose intolerance, anovulation and hyperandrogenism. Clinical phenotypes of PCOS show different patterns of steroid hormones that have been investigated to some extent. This study aimed to establish a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of salivary testosterone and androstenedione and to describe the salivary testosterone-to-androstenedione (T/A4) ratio as a new tool for the assessment of hyperandrogenism and metabolic health.

MATERIAL AND METHODS

Saliva and serum samples of 274 patients with PCOS and 51 healthy women were used for the quantification of steroid hormones. A comprehensive clinical and metabolic assessment was performed. Salivary testosterone and androstenedione were measured via LC-MS/MS. The salivary T/A4 ratio was calculated and correlated with hormones and metabolic parameters.

RESULTS

Salivary testosterone (P < 0·001), androstenedione (P < 0·001) and the salivary T/A4 ratio (P < 0·001) were significantly higher in patients with patients compared to healthy women. In patients with PCOS, a high salivary T/A4 ratio was associated with an adverse metabolic phenotype, that is glucose intolerance (P = 0·019), insulin resistance (P < 0·001), metabolic syndrome (P < 0·001), obesity (P < 0·001) and oligo-/anovulation (P = 0·001). Significant correlations of the salivary T/A4 ratio with adverse metabolic parameters were found.

CONCLUSION

Quantification of salivary androgens provides an attractive alternative to serum analysis and helps in characterizing metabolic health in women with PCOS. Our data show a strong link between a high salivary T/A4 ratio and an adverse metabolic phenotype in patients with PCOS.

Testosterone to dihydrotestosterone ratio as a new biomarker for an adverse metabolic phenotype in the polycystic ovary syndrome

CONTEXT

Polycystic ovary syndrome (PCOS) is a heterogeneous disease with many different aspects, including hyperandrogenism and metabolic disturbances. Clinical phenotypes show different patterns of steroid hormones that have been investigated to some extent.

OBJECTIVE

This study intended to determine the role of the testosterone (TT) to dihydrotestosterone (DHT) ratio (TT/DHT ratio) in PCOS patients and to further assess the correlation of this ratio with hormonal, anthropometric, and metabolic parameters.

DESIGN AND SETTING

Serum samples of 275 premenopausal PCOS patients fulfilling Rotterdam criteria and 35 BMI-matched, premenopausal, healthy controls were analyzed for testosterone, DHT, dehydroepiandrosterone (DHEA), and androstenedione using liquid chromatography/mass spectrometry.

MAIN OUTCOME MEASURES

We measured total levels of testosterone and DHT and calculated unbound hormone levels as well as the ratio of testosterone to DHT. Further, impaired glucose tolerance, basal and stimulated serum insulin levels, metabolic syndrome and insulin resistance according to the homeostatic model assessment (HOMA-IR) were assessed.

RESULTS

PCOS patients showed significantly higher levels of TT (P < .001), free testosterone (P < .001), and free DHT (P < .001) compared to healthy controls. The TT/DHT ratio was significantly higher in PCOS patients (P < .001). No difference was found for total DHT levels (P = .072). In PCOS patients alone, the TT/DHT ratio was significantly higher in obese patients (P < .001) and patients with metabolic syndrome (P < .001), impaired glucose tolerance (IGT) (P < .001) or insulin resistance (P < .001). Significant correlations of the TT/DHT ratio with various adverse anthropometric, hormonal, lipid and liver parameters and parameters of glucose metabolism were found.

CONCLUSION

Our data provide evidence for a strong link between a high TT/DHT ratio and an adverse metabolic phenotype in PCOS patients. This correlation was only found in PCOS patients, suggesting the TT/DHT ratio to be a new biomarker for an adverse metabolic phenotype in PCOS patients.

Age-associated changes in hypothalamic-pituitary-testicular function in middle-aged and older men are modified by weight change and lifestyle factors: longitudinal results from the European Male Ageing Study

OBJECTIVE

Health and lifestyle factors are associated with variations in serum testosterone levels in ageing men. However, it remains unclear how age-related changes in testosterone may be attenuated by lifestyle modifications. The objective was to investigate the longitudinal relationships between changes in health and lifestyle factors with changes in hormones of the reproductive endocrine axis in ageing men.

DESIGN

A longitudinal survey of 2736 community-dwelling men aged 40-79 years at baseline recruited from eight centres across Europe. Follow-up assessment occurred mean (±S.D.) 4.4±0.3 years later.

RESULTS

Paired testosterone results were available for 2395 men. Mean (±S.D.) annualised hormone changes were as follows: testosterone -0.1±0.95  nmol/l; free testosterone (FT) -3.83±16.8  pmol/l; sex hormone-binding globulin (SHBG) 0.56±2.5  nmol/l and LH 0.08±0.57  U/l. Weight loss was associated with a proportional increase, and weight gain a proportional decrease, in testosterone and SHBG. FT showed a curvilinear relationship to weight change; only those who gained or lost ≥15% of weight showed a significant change (in the same direction as testosterone). Smoking cessation was associated with a greater decline in testosterone than being a non-smoker, which was unrelated to weight change. Changes in number of comorbid conditions or physical activity were not associated with significant alterations in hypothalamic-pituitary-testicular (HPT) axis function.

CONCLUSIONS

Body weight and lifestyle factors influence HPT axis function in ageing. Weight loss was associated with a rise, and weight gain a fall, in testosterone, FT and SHBG. Weight management appears to be important in maintaining circulating testosterone in ageing men, and obesity-associated changes in HPT axis hormones are reversible following weight reduction.

5-hydroxytryptamine signalling in irritable bowel syndrome with diarrhoea: effects of gender and menstrual status

BACKGROUND

Symptomatology and physiology differ between men and women and across the menstrual cycle in irritable bowel syndrome (IBS). Ovarian hormones influence 5-hydroxytryptamine (5-HT), an amine known to play a role in gut motor-sensory function.

AIM

To assess the effects of gender and menstrual status on platelet-depleted plasma (PDP) 5-HT concentration in IBS patients with diarrhoea (IBS-D) patients compared with healthy volunteers (HV).

METHODS

Platelet-depleted plasma 5-HT concentrations were assessed under fasting and fed conditions in 73 IBS-D patients (aged 18-58 years; 18 men) and 64 HV (aged 18-50 years; 24 men). Women were divided into those with low or high progesterone/oestrogen (P/O) levels.

RESULTS

Irritable bowel syndrome patients with diarrhoea had higher PDP 5-HT concentrations than HV under fasting (P = 0.002) and fed (P = 0.049) conditions. This was particularly related to IBS-D men having higher PDP 5-HT concentrations than healthy controls (P = 0.002). Moreover, PDP 5-HT concentrations in IBS-D women with low P/O levels were similar to healthy controls.

CONCLUSIONS

Similar to IBS-D women with high P/O levels, IBS-D men also have raised PDP 5-HT concentrations. 5-HT concentration normalizes at menses in IBS-D women, suggesting a shift in the mechanisms responsible for abnormal 5-HT signalling in these patients.

Naturally occurring isotopes of an analyte can interfere with doubly deuterated internal standard measurement

Background

Internal standards are essential in quantitative mass spectrometry (MS) assays to correct for variability in sample extraction and ionization at the source. In liquid chromatography MS assays, analogues of the analyte with several atoms replaced by their stable isotopes, e.g. 2H (D, deuterium) are often used as internal standards.

Methods

Possible interference by naturally occurring isotopes of an analyte in the internal standard channel in a liquid chromatography tandem MS assay was assessed using cortisol and its deuterated internal standard, D2-cortisol, as an example. Mass spectra were analysed and standard curves were prepared with varying concentrations of internal standard to determine the extent of any interference.

Results

The mass spectra showed that a naturally occurring isotope of cortisol at m/z 365 acts in the same way as D2-cortisol and fragments to give a daughter ion of the same m/z. Cortisol-365 can therefore falsely, but significantly, increase the amount of internal standard detected, and this will concomitantly decrease the relative response for cortisol. The standard curves with varying concentrations of internal standard showed that this phenomenon can affect the linearity of an assay.

Conclusions

Our results show that care is needed in assay development when doubly deuterated internal standards are used. Interference by naturally occurring isotopes of the analyte of interest in the internal standard transition is possible and it is important to ensure that an appropriate internal standard concentration is chosen that permits linearity of the assay over the required range.

Sigmoid-colonic motility in health and irritable bowel syndrome: a role for 5-hydroxytryptamine

Abstract Evidence suggests that sigmoid-colonic motility is increased in patients with irritable bowel syndrome (IBS). 5-Hydroxytryptamine (5-HT) plays a role in the control of motility, but its involvement in the dysmotility seen in IBS remains unclear. To investigate the relationship between platelet depleted plasma 5-HT (PDP 5-HT) concentration and sigmoid-colonic motility in patients with IBS and healthy volunteers. Pre- and postprandial PDP 5-HT concentrations were assessed while recording sigmoid-colonic motility in 35 IBS patients (aged 19-53 years, eight male) and 16 healthy volunteers (aged 18-39 years, six male). Motility was recorded using a five-channel solid-state catheter introduced to a depth of 35 cm into an unprepared bowel. 5-Hydroxytryptamine concentration was measured by reverse-phase HPLC with fluorimetric detection. Irritable bowel syndrome patients had elevated concentrations of PDP 5-HT under fasting (P < 0.004) and fed (P = 0.079) conditions compared with controls. Likewise, they exhibited increased sigmoid-colonic motility under fasting (activity index: P < 0.02) and fed (P < 0.05) conditions compared with controls. Platelet depleted plasma 5-HT concentration positively correlated with colonic activity index under both fasting (r = 0.402; P = 0.003) and fed (r = 0.439; P = 0.001) conditions. These data show a possible relationship between endogenous concentrations of 5-HT and sigmoid-colonic motility recorded in both IBS and healthy subjects.

Cyclosporine Profiling With C2 and C0 Monitoring Improves Outcomes After Heart Transplantation

BACKGROUND

Cyclosporine (CsA) level at 2 hours post-dose (C2) is a more sensitive marker for rejection risk than trough (C0) level. A combination of C2 and C0 monitoring may prove optimal.

METHODS

We compared efficacy and safety outcomes among 28 de novo heart transplant patients in whom both C2 and C0 monitoring were undertaken (Group 1), with a single CsA profile at Weeks 2 to 6, versus 28 historic controls monitored by only C0 (Group 2). Patients received anti-thymocyte globulin (ATG) induction with CsA, steroids and azathioprine maintenance therapy.

RESULTS

The CsA microemulsion dose was significantly higher in Group 1 than Group 2 up to 3 months post-transplant. Mean C2 values in Group 1 at 3 and 12 months were 1,248 +/- 328 ng/ml and 1,039 +/- 362 ng/ml, respectively. One patient in Group 1 and 7 in Group 2 (25%) discontinued CsA, either due to CsA-related neurotoxicity or two or more episodes of early rejection. At 12 months, graft and patient survival were 100% in both groups. Six patients in Group 1 (21%) and 11 in Group 2 (39%) had at least one episode of biopsy-proven acute rejection (not significant). Over the first 12 months post-transplant, the proportion of biopsies showing Grade 3 rejection was 5% in Group 1 and 11% in Group 2 (p < 0.002). Gloerular filtration rate (GFR) was significantly lower in Group 1 than Group 2 at both 3 and 12 months.

CONCLUSIONS

Combined use of C2 and C0 monitoring results in improved efficacy versus C0 monitoring alone. Regular measurement of C2 levels should be undertaken in de novo heart transplant recipients.

The effects of ACE inhibition on serum angiotensin II concentration following cardiac transplantation

AIMS

ANGII mediates vascular neointimal formation through smooth muscle cell stimulation and enhanced production of growth factors leading to increased arterial medial layer thickness, which is a characteristic of transplant arteriosclerosis. ACE inhibition is known to be of benefit to patients with cardiovascular risk factors. We aimed to determine the effect of ACE inhibitor therapy on ACE enzymatic activity and serum ANGII levels following cardiac transplantation.

METHODS

A total of 43 serum samples from eight transplant recipients were used for analysis. Samples were taken monthly from the date of transplant for the initial 6 months. ANGII was measured using sandwich ELISA. ACE enzymatic activity was measured using spectrophotometric kinetic analysis.

RESULTS

There was a significant reduction in ACE enzymatic activity among individuals treated with ACE inhibitor therapy (18.0 +/- 16.6 vs 31.8 +/- 23.4, P = .008). We found significantly higher ANGII serum levels in patients receiving ACE inhibitor therapy compared to those not (2.4 +/- 2.1 vs 8.0 +/- 7.4, P = .002). There was also a significant positive correlation between ACE enzymatic activity and ANGII serum level (coefficient 0.332, P = .03).

CONCLUSIONS

Our results suggest an effective ACE independent pathway for ANGII conversion. Chymase can convert ANGI with higher affinity than ACE. Also, chymase is stored in mast cells, which infiltrate the myocardium following transplantation. This data indicate that pharmacological chymase inhibition may be a possible therapeutic strategy following transplantation.

Assessment of iron status in cystic fibrosis patients

We investigated the use of soluble transferrin receptor (sTfR), together with more traditional measurements such as iron, transferrin and ferritin, to assess iron status in 70 adult cystic fibrosis patients. sTfR concentration was measured using particle-enhanced immunonephelometry. We found that 69% of subjects as determined by transferrin saturation had iron deficiency, but only 29% as determined by sTfR and 11% as determined by ferritin. We found a significant correlation between C-reactive protein (CRP) and both ferritin (r = 0.38, P = 0.0001) and transferrin saturation (r = -0.54, P < 0.0001). In addition, because the CRP concentration was elevated in 64% of subjects, we feel that the transferrin saturation was overestimating, and the ferritin underestimating, iron deficiency in these patients. The sTfR concentration, on the other hand, is unaffected by the acute-phase response and was therefore thought to be the most useful test for detecting iron deficiency in this group of patients.

A new method for haptoglobin phenotyping

Haptoglobin is an acute-phase protein with three major phenotypes: Hp 1-1, Hp 2-1 and Hp 2-2. Studies have shown that functional differences between these phenotypes have important consequences in a number of pathological disorders (e.g. cardiovascular disease, autoimmune disorders, infectious disease), making phenotype determination of potential use in the clinical field. Previous methods for haptoglobin phenotyping have involved electrophoresis (starch, acetate and polyacrylamide gels) with phenotype visualization by peroxidase-sensitive stains that were often carcinogenic. Less hazardous immunoblotting and isoelectric focusing procedures are also available but the methods are lengthy, expensive and often complex. Here, we describe a new method for haptoglobin phenotyping using commercially available agarose gels and a non-carcinogenic stain (3,3',5,5'-tetramethylbenzidine). Our method showed 100% agreement with starch gel electrophoresis and reliably distinguished between commercial haptoglobin phenotype standards and serum samples from patients (n = 125). We obtained a sensitivity of 0.4 g/L for all phenotypes and the gels were stable for up to 2 months. This safer and easier to use method may permit increased access to knowledge of haptoglobin phenotype, allowing improved patient management and better tailoring of treatment in a variety of clinical conditions.

The effect of 'renal-dose' dopamine on renal tubular function following cardiac surgery: assessed by measuring retinol binding protein (RBP)

OBJECTIVE

Acute renal failure complicating open heart surgery is not uncommon. Dopamine infusion (2.5-4.0 microg/kg per min) has often been advocated for prophylactic 'renal protection' in this setting despite little objective evidence of real benefit. We aimed to investigate whether dopamine offers any 'renal protection' in patients with normal heart and kidney functions undergoing routine coronary artery bypass grafting (CABG). Urinary excretion of retinol-binding protein (RBP), previously validated as a sensitive and accurate marker of early renal tubular injury, was used to assess the renal effects of dopamine during the first postoperative week.

METHODS

Forty consecutive patients from the elective waiting list were prospectively randomized into two equal groups: those in Group A received dopamine infusion at 'renal dose' (2.5-4.0 microg/kg per min) starting from induction of anaesthesia for 48 h, whereas those in Group B served as untreated controls. Daily measurements were made of weight-adjusted urine output (ml/kg), fluid balance (input/output), serum creatinine, blood urea and urinary RBP. Statistical comparisons were made using Mann-Whitney U-test.

RESULTS

The two groups matched in terms of age, time and temperature on cardiopulmonary bypass, number of grafts performed and perioperative haemodynamic status. No differences were detected in the weight-adjusted urine output, fluid balance, serum creatinine and blood urea between the groups. Control subjects (Group B) showed an increase in urinary RBP during the first and second postoperative days (323+/-4 microg/ mmolCr and 50+/-3 microg/mmolCr; mean+/-SD). However, patients treated with dopamine (Group A) demonstrated much greater urinary excretion of RBP over the same period (1257+/-15 microg/mmolCr and 449+/-21 microg/mmolCr; P = 0.0006 and 0.03) than those in Group B.

CONCLUSIONS

Dopamine given at 'renal-dose' appears to offer no renal protection in patients with normal heart and kidney functions undergoing elective coronary surgery. On the contrary, it exacerbates the severity of renal tubular injury during the early postoperative period. Based on these findings we do not recommend the use of dopamine for routine renal prophylaxis in this group of patients.

Significance of raised natriuretic peptides after bicaval and standard cardiac transplantation

BACKGROUND

High levels of plasma atrial natriuretic peptide (ANP) and ventricular natriuretic peptide (BNP) have been identified after standard orthotopic cardiac transplantation. It has been postulated that the high ANP levels are a result of persistent secretion from the large residual atrial mass after transplantation. This study was undertaken to investigate the significance of raised ANP and BNP levels after standard and bicaval orthotopic heart transplantation.

METHODS

Plasma ANP and BNP levels were measured in 40 ambulatory, randomly selected cardiac transplant patients (group A, n = 20 had bicaval transplantation; group B, n = 20 had standard transplantation) and 10 healthy volunteers (group C). Cardiac transplant patients underwent endomyocardial biopsy and hemodynamic evaluation.

RESULTS

Plasma levels of ANP and BNP were elevated in the transplant recipients in comparison with normal volunteers (p = 0.0001 and p < 0.0001, respectively). There was no significant difference in the ANP levels between group A and group B, whereas BNP levels were higher in group B compared with group A (p = 0.03). Linear regression analysis showed that a faster heart rate, high mean pulmonary artery pressure, high pulmonary capillary wedge pressure, and high transpulmonary gradient were associated with higher levels of BNP (p < 0.05). Lower mean systemic pressure was associated with higher levels of ANP (p < 0.05).

CONCLUSIONS

High levels of ANP and BNP are synthesized and secreted by the transplanted denervated human heart regardless of the surgical technique. The level of BNP correlates with ventricular performance and afterload. The bicaval technique seems to be associated with better left ventricular and right ventricular diastolic performance.

Cardiac allograft rejection: do trough cyclosporine levels correlate with the grade of histologic rejection?

BACKGROUND

The introduction of cyclosporine to heart transplantation immunosuppressive protocols has been associated with an improvement in the long- and short-term survival rates. The ideal dose of cyclosporine that maximizes its immunosuppressive properties and minimizes its toxicity has remained an enigma since its introduction. This study was undertaken to evaluate which range of cyclosporine levels provided the most effective protection against graft rejection.

METHODS

We studied the correlation between cyclosporine levels and histologic grade of rejection, cardiac function, and renal function by retrospectively analyzing the results of 1407 individual whole blood cyclosporine trough levels. One hundred seven heart transplant recipients were studied within 2 years of undergoing transplantation. As a historical comparison, we also studied 146 individual trough cyclosporine levels from a subgroup of patients (n = 14) who had acute cellular rejection with graft dysfunction or failure. We correlated trough cyclosporine levels with the histologic severity of cellular rejection, cardiac function (right cardiac catheterization), and serum creatinine in both groups. The correlation was performed within patient's own data rather than between patient groups to avoid interpatient variations.

RESULTS

The mean cyclosporine level was significantly higher (206 ng/ml) when the patients had grade 0 cellular rejection in comparison to grade 3A, with a mean cyclosporine level of 173 ng/ml (p = 0.005). Patients with graft dysfunction or failure had higher mean cyclosporine level (230 ng/ml) when they had no rejection compared with 3A rejection with a mean cyclosporine level of 153 ng/ml (p = 0.001). Furthermore, lower cyclosporine levels were associated with graft dysfunction. There was no correlation between serum creatinine and cyclosporine levels (r = 0.059, r2 = 0.351%).

CONCLUSION

We conclude that cyclosporine trough levels above 200 ng/ml in the first 2 years after heart transplantation are associated with reduced cellular rejection without deleterious effects on renal function.

Severe theophylline poisoning: charcoal haemoperfusion or haemodialysis?

Theophylline poisoning with a blood level of 183 mg/l in a 38-year-old man was treated with activated charcoal by mouth, but despite this the blood level of theophylline rose and there was circulatory collapse with rhabdomyolysis, acute renal failure and hyperthermia. Treatment with charcoal haemoperfusion and simultaneous haemodialysis was given, followed by continuous arteriovenous haemodialysis (CAVHD). Mean extraction rates of theophylline were 26% during CAVHD, and 86% during combined dialysis and charcoal haemoperfusion. During combined treatment, the mean extraction rate of haemodialysis was 62%, compared with 48% for charcoal haemoperfusion. In summary, activated charcoal given by mouth may be unable to prevent a rise in blood levels and the development of complications after substantial theophylline overdose. If theophylline is to be removed from the blood, a combination of charcoal haemoperfusion and haemodialysis will give the best clearance, but haemodialysis alone may be effective.

Serum ferritin in recurrent oral ulceration

A sensitive radio-assay for ferritin was developed and used to examine serum ferritin levels in 105 patients with recurrent oral ulceration (ROU), 41 patients with Behçet's syndrome (BS), 42 with other ulcerative oral lesions, 35 patients with non-ulcerative oral lesions and in 78 controls. Ferritin levels increased with age and were significantly higher in males than females. The mean ferritin concentrations in male patients with ROU, BS or with other oral ulcers were significantly reduced in comparison with controls, and in female patients were significantly reduced in those with major aphthous ulcers. The prevalence of low serum ferritin levels was about 8% in patients with ROU, 15% in BS and 9.5% in patients with other ulcerative oral lesions, compared with less than 3% in patients with non-ulcerative oral disorders and in controls. Most of the iron-deficient patients were female. Serum ferritin levels did not directly correlate with serum iron levels and may be a more accurate indicator of iron deficiency. Furthermore, serum ferritin can distinguish between patients with true iron deficiency and those with secondary sideropenia. It is suggested that in a small number of patients, oral ulceration may be a presenting sign of iron deficiency, and that in a further small proportion of patients, ROU already present will be exacerbated by concurrent iron deficiency. Both groups will show a therapeutic response to correction of the iron deficiency. The results suggest that serum ferritin levels are a useful part of the haematological investigations in patients with ROU.