Septal flash correction with His-Purkinje pacing predicts echocardiographic response in resynchronization therapy

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Grant of the Catalan Society of Cardiology, 2019; Research Grant Josep Font 2019, Hospital Clínic de Barcelona

His-Purkinje conduction system pacing (HPCSP) has been proposed as an alternative to cardiac resynchronization therapy (CRT); however, no predictors of echocardiographic response have been described. Septal flash (SF) is a marker of intraventricular dyssynchrony.

Methods

The study aimed to analyze whether HPCSP corrects SF in patients with CRT indication, and if correction of SF predicts echocardiographic response. Prospective observational study (n=30). Left ventricular ejection fraction (LVEF) was measured with echocardiography at baseline and at 6-month follow-up. Echocardiographic response was defined as increase in 5 points LVEF. ECG Imaging was performed in 2 patients to validate ventricular activation shortening and to study the basal and HPCSP activation pattern.

Results

HPCSP shortened QRS duration by 48±21ms and SF was significantly decreased (baseline 3.6±2.2mm vs HPCSP 1.5±1.5mm p<0.0001) (Fig.1). At 6-months, mean LVEF improvement was 8.6% ± 8.7% and 64% of patients were responders. There was a significant correlation between SF correction and increased LVEF (r=0.61, p=0.004). A correction of >1.5mm had 81% sensitivity and 80% specificity to predict echocardiographic response (area under curve 0.86, p=0.019).

Conclusion

HPCSP improves intraventricular dyssynchrony and results in 64% echocardiographic responders at 6-month follow-up. Dyssynchrony improvement with SF correction may predict echocardiographic response at 6-month follow-up (Fig.2.).

Predictive factors for requiring heart transplantation in patients with hypertrophic cardiomyopathy: data from a referral center

Background

Heart transplant (HT) remains the last treatment option for patients with non-obstructive hypertrophic cardiomyopathy (HCM) who develop end-stage heart failure (HF). Early identification of patients who may require a HT in the future is crucial in order to advise them, establish the appropriate follow-up and determine the appropriate time to include them in the waiting list.

Objectives

Our study sought to find predictive factors related with requiring HT during follow-up in patients with HCM.

Methods

Consecutive patients with HCM referred to a HCM monographic clinic from 2018 to 2020 (HCM controls) and transplanted patients due to HCM in the same tertiary HT hospital since 2003 (cases) were included. Baseline (on the date of HCM diagnosis) and longitudinal data regarding clinical, genetic, ECG and echocardiographic variables were retrospectively evaluated. Follow-up was registered from HCM diagnosis to HT (in cases) or last medical check up (controls).

Results

A total of 157 patients (24 HCM-HT cases and 133 HCM controls) were included (45±19 yo; 57% male). At the time of MCH diagnosis (Table), cases were significantly younger than controls, were more frequently symptomatic and showed significantly higher BNP levels and more advanced diastolic dysfunction (larger left atrium, higher E/A ratio and lower e'); also, HCM-HT reported more family history and had higher proportion of pathogenic mutations (being MYH7 the most frequently involved). Left ventricular (LV) systolic function was slightly reduced in HCM-HT cases. In contrast, HCM controls were more frequently diagnosed by casual findings or family screening and had more LV outflow tract obstruction at first medical evaluation. LV maximal wall thickness (MWT) did not differ between groups. During a median follow-up since HCM diagnosis of 6.2 years (median follow-up of 8.9 and 7.1 years in cases and controls, respectively), HCM-HT cases presented a higher incidence of sustained ventricular tachycardia or ICD therapy (HR=4.0; CI95%:1.6–10.0 p=0.03) and HF admissions (HR=3.9; CI95%:1.8–8.1 p<0.001). There were no cardiovascular deaths during follow-up.

Conclusions

The presence of symptoms in a young non-obstructive HCM patient, along with family history and a pathogenic mutation, should advice clinicians a closer follow-up and early transfer to a HT referral center, especially if associated with diastolic dysfunction and high BNP values.

Funding Acknowledgement

Type of funding sources: None. Table 1

Changes in Pulmonary Function in Patients With Advanced Heart Failure Listed for Heart Transplantation

BACKGROUND

Pulmonary function tests (PFTs) are often impaired in patients with advanced heart failure. There is limited data about their impact on survival after heart transplantation (HT). We sought to assess the prevalence and type of PFT abnormalities in patients on HT waiting list and their impact on outcomes.

METHODS

We performed a retrospective analysis of a prospective registry of consecutive patients undergoing HT between 2012 and 2018. Patients were classified into 4 groups according to pre-HT PFT results: 1. normal pattern: forced vital capacity (FVC) ≥ 80% and forced expiratory volume in 1 second (FEV₁) to FVC ratio (FEV₁/FVC) ≥ 0.7; 2. obstructive: FEV₁/FVC < 0.7; 3. nonobstructive: FEV₁/FVC ≥ 0.7 and FVC < 80% when total lung capacity value was not available; and 4. restrictive: FEV₁/FVC ≥ 0.7 and total lung capacity < 80%. The prevalence of impaired carbon monoxide diffusing capacity corrected for hemoglobin < 80% and FEV₁ < 70% was also analyzed. High-urgency HT patients and those referred from other centers without quantitative pulmonary evaluation were excluded.

RESULTS

Among 123 patients who underwent HT, 83 patients with complete PFT were included. Median follow-up was 2.7 ± 1.9 years. Of these, 29 (34.9%) had an obstructive pattern, 20 (24.1%) a nonobstructive, 18 (21.7%) a restrictive, and 16 (19.3%) a normal pattern. Fifty-one (61.4%) patients had FEV₁ < 70% and 58 (69.9%) a carbon monoxide diffusing capacity corrected for hemoglobin < 80%. There was a tendency to lower survival in all altered PFT groups compared with normal (P = .054) but not within the other groups. Patients with an impaired FEV₁ had significantly higher mortality than patients with normal values (P = .008). Area under receiver operating characteristic curve for FEV₁ was 0.73 (95% confidence interval [0.60-0.86]). A cutoff value of FEV₁ (60.5) predicts mortality with 66% sensitivity and 64% specificity.

CONCLUSIONS

PFT alterations have a very high prevalence on HT waiting list patients. Patients with impaired FEV₁ had worse outcomes after heart transplantation.

Use of serum levels of high sensitivity troponin T, galectin-3 and C-terminal propeptide of type I procollagen at long term follow-up in heart failure patients with reduced ejection fraction: Comparison with soluble AXL and BNP

BACKGROUND

Prognostic biomarkers are needed to improve the management of the heart failure (HF) epidemic, being the brain natriuretic peptides the most valuable. Here we evaluate 3 biomarkers, high sensitivity troponin T (hs-TnT), galectin-3 (Gal-3) and C-terminal propeptide of type I procollagen (CICP), compare them with a recently described new candidate (sAXL), and analyze their relationship with BNP.

METHODS

HF patients with reduced ejection fraction (n=192) were included in this prospective observational study, with measurements of candidate biomarkers, functional, clinical and echocardiographic variables. A Cox regression model was used to determine predictors for clinical events, i.e. all-cause mortality and heart transplantation.

RESULTS

Hs-TnT circulating values were correlated to clinical characteristics indicative of more advanced HF. When analyzing the event-free survival at a mean follow-up of 3.6years, patients in the higher quartile of either BNP, hs-TnT, CICP and sAXL had increased risk of suffering a clinical event, but not Gal-3. Combination of high sAXL and BNP values had greater predictive value (HR 6.8) than high BNP alone (HR 4.9). In a multivariate Cox regression analysis, BNP, sAXL and NYHA class were independent risk factors for clinical events.

CONCLUSIONS

In this HF cohort, hs-TnT is a good HF marker and has a very significant prognostic value. The prognostic value of CICP and sAXL was of less significance. However, hs-TnT did not add predictive value to BNP, while sAXL did. This suggests that elevated troponin has a common origin with BNP, while sAXL could represent an independent pathological mechanism.

Data on clinical characteristics of a heart failure patients' cohort with reduced ejection fraction and analysis of the circulating values of five different heart failure biomarkers; high sensitivity troponin T, galectin-3, C-terminal propeptide of type I procollagen, soluble AXL and BNP

In this article, the full description of a heart failure with reduced ejection fraction (HF_REF) cohort of 192 patients is provided. Tables with the baseline demographic, prior history, ECG parameters, echocardiographic parameters, laboratory values and pharmacological treatment of these patients are included. Also, the quartile values of the analyzed circulating biomarkers: high sensitivity Troponin T (hs-TnT), galectin-3 (Gal-3), C-terminal propeptide of type I procollagen (CICP), soluble AXL (sAXL) and Brain Natriuretic Peptide (BNP) are given. The main demographic and clinical features of the patients’ subgroups that have hs-TnT, Gal-3, CICP or BNP above the third quartile are described. Tables with Pearson correlation analysis of the HF_REF patients’ biomarker levels are included. And Pearson correlation analysis of the HF_REF patients’ hs-TnT, Gal-3, CICP levels with patients’ biochemical parameters, blood count and inflammation parameters are also described. These data are related to the research articles (AXL receptor tyrosine kinase is increased in patients with heart failure (M. Batlle, P. Recarte-Pelz, E. Roig, M.A. Castel, M. Cardona, M. Farrero, et al., 2014) [1] and Use of serum levels of high sensitivity troponin T, galectin-3 and C-terminal propeptide of type I procollagen at long term follow-up in Heart Failure patients with reduced ejection fraction: comparison with soluble AXL and BNP (M. Batlle, B. Campos, M. Farrero, M. Cardona, B. González, M.A. Castel, et al., 2016) [2].

An Update on Heart Transplantation in Human Immunodeficiency Virus-Infected Patients

Cardiovascular diseases have become a significant cause of morbidity in patients with human immunodeficiency virus (HIV) infection. Heart transplantation (HT) is a well-established treatment of end-stage heart failure (ESHF) and is performed in selected HIV-infected patients in developed countries. Few data are available on the prognosis of HIV-infected patients undergoing HT in the era of combined antiretroviral therapy (cART) because current evidence is limited to small retrospective cohorts, case series, and case reports. Many HT centers consider HIV infection to be a contraindication for HT; however, in the era of cART, HT recipients with HIV infection seem to achieve satisfactory outcomes without developing HIV-related events. Consequently, selected HIV-infected patients with ESHF who are taking effective cART should be considered candidates for HT. The present review provides epidemiological data on ESHF in HIV-infected patients from all published experience on HT in HIV-infected patients since the beginning of the epidemic. The practical management of these patients is discussed, with emphasis on the challenging issues that must be addressed in the pretransplant (including HIV criteria) and posttransplant periods. Finally, proposals are made for future management and research priorities.

Toxoplasmic encephalitis associated with meningitis in a heart transplant recipient

Toxoplasma gondii is an opportunistic pathogen that causes neurologic and extraneurologic manifestations in immunosuppressed patients. Encephalitis and intracranial mass lesions are easily recognized as typical manifestations of toxoplasmosis. However, meningitis caused by T. gondii is a rare condition with very few cases described in the literature. We present the case of a heart transplant recipient who developed toxoplasmic encephalitis associated with meningitis. After an extensive review of the medical literature, we found only 1 case of meningitis in solid organ transplant recipients and <25 cases in immunosuppressed patients, such as patients infected with human immunodeficiency virus or those with Hodgkin's disease. In this report, we consider toxoplasmosis in the differential diagnosis of meningitis in immunocompromised individuals.

AXL receptor tyrosine kinase is increased in patients with heart failure

BACKGROUND

AXL is a membrane receptor tyrosine kinase highly expressed in the heart and has a conspicuous role in cardiovascular physiology. The role of AXL in heart failure (HF) has not been previously addressed.

METHODS AND RESULTS

AXL protein was enhanced 6-fold in myocardial biopsies of end-stage HF patients undergoing heart transplantation compared to controls from heart donors (P<0.0001). Next, we performed a transversal study of patients with chronic HF (n=192) and a group of controls with no HF (n=67). sAXL and BNP circulating levels were quantified and clinical and demographic data were collected. sAXL levels in serum were higher in HF (86.3 ± 2.0 ng/mL) than in controls (67.8 ± 2.0 ng/mL; P<0.0001). Also, sAXL correlated with several parameters associated with worse prognosis in HF. Linear regression analysis indicated that serum creatinine, systolic blood pressure and atrial fibrillation, but not BNP levels, were predictive of sAXL levels. Cox regression analysis indicated that high sAXL values at enrollment time were related to the major HF events (all-cause mortality, heart transplantation and HF hospitalizations) at one year follow-up (P<0.001), adding predictive value to high BNP levels.

CONCLUSIONS

Myocardial expression and serum concentration of AXL is elevated in HF patients compared to controls. Furthermore, peripheral sAXL correlates with parameters associated with the progression of HF and with HF events at short term follow-up. All together these results suggest that sAXL could belong to a new molecular pathway involved in myocardial damage in HF, independent from BNP.

Primary immunosuppression and outcome differences after heart transplantation: tacrolimus versus cyclosporine

BACKGROUND

The superiority of tacrolimus (Tac) as primary immunosuppression for heart transplantation (HT) compared with cyclosporine (CsA) is still under debate. Outcomes of comparison studies are not consistent; the duration of these studies has been limited. The aim of this study was to evaluate long-term outcomes of patients undergoing HT based on primary immunosuppression regime.

METHODS AND RESULTS

We analyzed a single-center registry of all HT patients between 1998 and 2009, comparing outcomes based on primary immunosuppressions (Tac or CsA). Patients who died before starting immunosuppression were excluded. A total of 197 patients entered the study; 103 received Tac and 94 CsA. There were no differences between groups in baseline characteristics, United Network for Organ Sharing status 1A or ventricular assist device use, except for ischemia time (195 ± 50 min in Tac group vs 182 ± 55 min in CsA; P = .08) and days on waiting list (164 ± 155 vs 100 ± 73; P < .001). After mean follow-ups of 4.5 ± 2.3 years in the Tac group and 6.3 ± 4.3 years in the CsA group, there were 19 and 36 deaths, respectively. Kaplan-Meier analysis showed increased survival for the Tac group (log rank P = .04). Tac also was significantly superior to CsA regarding mortality (relative risk 0.55; 95% confidence interval, 0.31-0.98; P = .04).

CONCLUSIONS

In our series the use of tacrolimus resulted in improved long-term survival compared with cyclosporine. At 1-year follow-up, there were no differences in acute rejection episodes or the appearance of vasculopathy.

Outcome after steroid withdrawal in heart transplantation

BACKGROUND

There is a lack of consensus and insufficient data to assess the impact of late steroid withdrawal after heart transplantation (HTx). The aim of the study was to investigate the security and feasibility of corticosteroid withdrawal at 1 year after transplantation.

METHODS AND RESULTS

Steroid withdrawal was attempted after at least 12 months of treatment in 86 HTx patients who fulfilled the criteria. At 1 and 3 months after drug discontinuation, patients underwent 2 endomyocardial biopsies (EMB). After a mean follow-up of 25 +/- 13 months, 63% of the patients remained steroid free. In 30 patients (35%) corticosteroids were reinitiated, in 15 cases because of acute rejection (7%), 5 (6%) because of worsening renal function, 5 (6%) because of malignancy, 3 (4%) because of adverse effects of immunosuppressive drugs, and 2 because of severe allograft coronary artery disease. Four patients (5%) died after drug discontinuation. There was a significant decrease in total cholesterol (198 +/- 35 to 181 +/- 38 mg/dL; P < .001) and low-density lipoprotain (LDL) cholesterol levels (113 +/- 30 to 105 +/- 30 mg/dL; P < .001). There were no differences in mortality between patients with and without corticosteroids.

CONCLUSION

Steroid withdrawal is feasible and safe in HTx patients. In our study, it was successfully maintained in 63% of the patients. EMB is helpful to identify patients with acute rejection at 1 and 3 months after withdrawal. Short- to mid-term metabolic benefits are significant reductions in serum total and LDL cholesterol.

Hemodynamic changes during cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) is a new method for the correction of inter- and/or intraventricular conduction delays of patients with heart failure. The long-term impact of CRT on central hemodynamics is not fully characterized. We performed complete right heart catheterization studies in 31 patients receiving a CRT device pre and 6 months after implantation. Most of the patients improved in their NYHA stage, their LVEF, and in parallel showed reduced right atrial (RA) pulmonary artery (PA) and pulmonary capillary wedge (PCW) pressures and pulmonary vascular resistance both at rest and at 25 watts. In addition, we found a reduction in heart rate accompanied by an increased mean arterial pressure both at rest and at 25 watts. Accordingly, brain natriuretic peptide levels (BNP) were lowered. It was concluded that, besides other well-known effects on ventricular coordination, central hemodynamics after 6 months were improved during CRT.

Analysis of terminal arrhythmias stored in the memory of pacemakers from patients dying suddenly

AIMS

Stored electrograms or marker channels are available in most of modern cardiac pacemaker models. We sought to analyse these information to uncover terminal events of pacemaker patients dying suddenly. Method and results We made post-mortem pacemaker (PM) interrogations in 19 patients dying suddenly out of hospital between the years 1997 and 2005 (mean age 59 +/- 13 years, 90% males). The systems had activated arrhythmia monitoring algorithms. Indications of pacing were sick sinus syndrome in seven, AV-block in five, and heart failure due to asynchrony in seven cases. The interrogated pacemakers were CHORUS 7034 (n = 12), CONTAK TR (n = 2), and INSYNC III (n = 5). For interpretation stored marker channels and electrograms were analysed. The mean observation time after PM implantation prior death was 2.11 +/- 1.44 years, the mean left ventricular ejection fraction from the last available echo examination in the year prior death was 27.5 +/- 8%, mean age was 63 +/- 12 years. In 17/19 cases (89%), a tachycardia (most likely ventricular tachycardia) was found correlating to the time of death. The mean cycle length of the terminal arrhythmia was 307 +/- 144 (250-344) ms, corresponding to a heart rate of 195 +/- 95 (174-240) bpm. We found no evidence of specific pacemaker-related problems such as electronic failure, battery depletion, or undersensing.

CONCLUSIONS

Post-mortem analysis of arrhythmia monitoring of pacemaker patients revealed tachycardias (most likely ventricular tachycardia) to be related to sudden death. These findings give some insight in mechanisms of terminal events in this group.

First experience with a new active fixation coronary sinus lead

AIMS

Coronary sinus (CS) lead implantation is a technically challenging procedure owing to variable vein anatomies and a high dislocation rate. Therefore, CS lead technology has undergone evolutionary changes during the last 10 years. The mode of fixation has been a passive one up to now. We want to describe our first clinical experience with the newly available active fixation lead 4195 in terms of dislocation rate and stability of thresholds compared with conventional models.

METHODS AND RESULTS

From 1999 to February 2007, we implanted 403 CS leads in 368 patients. Leads were categorized into three different groups on the basis of their fixation mechanism: straight (Easytrak I and Situs OTW; n = 54), curved (Attain 4193 and 4194, Corox, Aescula, Situs ULD; n = 308), and active (Attain 4195; n = 41). Operative and follow-up data were prospectively noted and checked for significance between groups during the first 3 months after implantation. Kaplan-Meier analysis of long-term lead function was also performed. Straight and curved CS leads suffered from significantly more dislocations compared with active fixation (P < 0.001). The active fixation lead (4195) has a stable threshold over time compared with a significant rise after 24 h and thereafter in straight (62%) and curved leads (20%). However, retraction of an active fixation CS lead may be a difficult issue as outlined in two cases requiring pullback of a 4195 lead owing to phrenic nerve stimulation (one unsuccessful despite vigorous traction).

CONCLUSION

The active fixation lead 4195 using retention lobes yielded stable thresholds over time and seems to be superior to conventional leads in terms of dislocation. However, extraction may be a difficult or even impossible task.

Long-term hemodynamic benefit of biventricular pacing depending on coronary sinus lead position

BACKGROUND

Acute studies in cardiac resynchronization therapy (CRT) showed that hemodynamic effects may depend on the coronary sinus (CS) lead position. However, there are no data on the longterm effect of CS lead position.

METHODS

In 45 heart failure patients with left bundle branch block and QRS >150 ms (age 59+/-10 years, 17 dilative cardiomyopathy, 23 ischemic, 5 valvular), biventricular pacemakers were implanted. CS leads were positioned in posterior (P, n=15), lateral (L, n=19) or, if no other option available, anterior (A, n=11) side branches. Before and 6 months after implantation, clinical state, echocardiography, brain natriuretic peptide (BNP) and right heart catheterization were evaluated.

RESULTS

Baseline parameters were similar between groups. After 6 months, there were 32/34 responders in groups P and L compared to 7/11 responders in group A (94 vs groups P and L: Arterial pressure +8 and +9% vs +2%; PCWP -23 and -15% vs -4%, pulmonary pressure -18 and -12% vs -3% (p<0.01 for A vs P+L); cardiac index +21 and +12% vs +11% (p=0.03 for A vs P). BNP was reduced by 55, 35, and 27% (p=0.05 for A vs P). Ejection fraction increased in P and L by 40 and 41%, respectively, but only by +19% in A (p<0.03 for A vs P+L).

CONCLUSION

Chronic CRT improves ejection fraction, BNP and hemodynamic measurements predominantly in patients with lateral and posterior CS lead positions. Anterior lead positions should be avoided.

Experience with coronary sinus lead implantations for cardiac resynchronization therapy in 244 patients

INTRODUCTION

Cardiac resynchronization therapy (CRT) using coronary sinus (CS) leads is a new method for the therapy of congestive heart failure (CHF). Because the intervention is more complex than regular pacemaker implantations, information on the feasibility and side effects of this method are of interest.

METHODS

From 1999 to June 2005, CRT implantations were attempted in 244 patients (pts; mean age 64+/-12 years, range 14-90 years), 82% were male, 44% had coronary artery disease, 29% were in atrial fibrillation, 71 had preexisting pacemakers.

RESULTS

In 97% of the pts the intervention was successful (27% of the systems with defibrillation capabilities). In 285 interventions, 255 CS leads were positioned according to CS vein anatomy in 130 posterolateral, 97 anterolateral and 28 anterior side branches (16 patients received 2 CS leads). Over-the-wire leads were used in 88%, 71% were additionally preshaped. We observed no mortality but 37 complications (12.5%): CS dissection in 9, CS perforation in 1, ventricular fibrillation in 4, asystole in 5, pulmonary edema in 1, pneumothorax in 2, need for early CS lead revision in 19 (dislodgement n=7, phrenic nerve stimulation n=12) and infection with explantation in 2 cases. An improvement in NYHA functional class was found in 88% of pts (only 55% if anterior lead position).

CONCLUSION

Perioperative complications during CS lead implantation occur in 10-15% of cases. Most patients responded well to CRT. Patients should be informed about the possible need for a reoperation. During implantation, immediate defibrillation and stimulation capabilities must be available. Anterior lead positions should be avoided.

Heart transplantation in a patient with multiple sclerosis and mitoxantrone-induced cardiomyopathy

We describe a 30-year-old man with end-stage heart failure after therapy with mitoxantrone for multiple sclerosis. A successful orthotopic heart transplantation was performed when intensified medical therapy failed to improve the patient's hemodynamics. In spite of the severe underlying disease he did well on dual immunosuppression with methylprednisone and cyclosporine. Neurologic symptoms remained stable throughout the procedure and, after 2 months, he resumed preoperative ambulatory status. Eight years after the operation, the patient is now in New York Heart Association (NYHA) Class I status. Using canes, he is able to walk short distances. Repeated urinary tract infections caused by Escherichia coli became a problem, but have been controlled by long-term oral antibiotic prophylaxis with trimethoprim.

Testosterone levels in men with chronic obstructive pulmonary disease with or without glucocorticoid therapy

Under the clinical impression that patients with chronic obstructive pulmonary disease (COPD) may demonstrate signs compatible with hypogonadism, we investigated whether oral glucocorticoid therapy is associated with testosterone deficiency. Thirty six men with COPD of whom 16 were receiving oral glucocorticoid medication (mean+/-SEM dose 9.4+/-1.1 mg prednisolone) were investigated in a cross-sectional cohort study. Patients with or without oral glucocorticoid therapy were not different in terms of age, smoking history and additional therapy. Vital capacity, forced expiratory volume in one second, airway resistance, intrathoracic gas volume and blood gases at rest were not different between the groups. However, patients receiving glucocorticoids had a shorter 6 min walking distance (mean+/-SEM 205+/-27 versus 288+/-26 m; p=0.02) compared to patients without oral steroid therapy. Serum levels of testosterone (mean+/-SEM 13.7+/-0.9) were below normal (<12 nM) in 15 of 36 patients. Serum testosterone did not correlate with any other evaluated parameter. Serum levels of free testosterone (free T) (mean+/-SEM 172.3+/-7.8 pM) were decreased in 25 of the 36 patients, including all patients receiving glucocorticoid treatment. In the 16 patients taking glucocorticoids free T was correlated (p=0.016) with the current glucocorticoid dosage (r=-0.504; p=0.007) and the body mass index (r=0.241; p=0.037). All other parameters examined revealed no significant correlations in multiple regression analysis. Glucocorticoid treatment appears to aggravate hypogonadism and a therapeutic study using testosterone in patients with chronic obstructive pulmonary disease receiving glucocorticoid medication appears warranted.

The antibodies causing thyroid stimulating hormone-binding inhibition (TSH-BI) are not responsible for the specific inhibition of gonadal steroidogenesis by Graves' sera

Graves' disease is attributed to the presence of autoantibodies with agonist activity which interact with the TSH receptor causing thyroid hyperstimulation and hyperthyroidism. The degree of TSH-binding inhibition (TSH-BI) caused by a Graves' serum in a TSH radioligand receptor assay is considered to be an index of the prevalence of anti-TSH receptor autoantibodies in that serum. We have previously shown that the specific inhibition by Graves' serum of hCG-stimulated steroidogenesis by Leydig cells was at a site distal to receptor binding and second messenger activation. In this report, we have investigated whether the effect of Graves' serum upon Leydig cells is a property of the constitutive antibodies. Immunoglobulin-enriched fractions were obtained from Graves' and normal sera using three increasingly rigorous procedures; ammonium sulphate precipitation, caprylic acid treatment and Protein A or G-affinity purification. The TSH-BI was determined for untreated and extracted sera in two radioreceptor assays developed for use with serum, one using human thyroid membranes and the other using HeLa cells transfected with the human TSH receptor, and the results were compared with effects in the Leydig cell steroidogenesis bioassay. The specific inhibition of hCG-stimulated Leydig cell steroidogenesis by Graves' sera was not retained in the antibody fraction causing TSH-BI. Thus, the inhibitory factor appears not to be an antibody and we are now attempting to purify and identify the responsible factor from Graves' serum.

Graves' autoimmune serum inhibits gonadal steroidogenesis: development of a Leydig cell bioassay to identify broad spectrum anti-endocrine autoantibodies

In order to establish an assay for the detection of autoimmune sera with broad spectrum activity, we have investigated the effect of unselected normal and Graves' disease sera upon steroidogenesis by gonadal cells. Steroidogenesis was enhanced by the addition of normal serum in a 3-h primary Leydig cell bioassay, but was inhibited by the majority of Graves' sera. The inhibition was not related to clinical thyroid parameters, such as the severity of the TSH-binding inhibition index, and was not overcome by other agonists or second messenger supplements. Although pituitary TSH preparations bound to and stimulated Leydig cells, TSH receptor mRNA was not detectable and pure recombinant TSH failed to bind or stimulate, indicating contamination of pituitary TSH with LH. The binding of hCG to the Leydig cell luteinizing hormone receptor was not perturbed by the Graves' autoimmune sera, indicating that cross-reactive anti-TSH receptor antibodies were not responsible for the inhibition. By use of intermediates in the stimulatory pathway, the site of Graves' serum inhibition was identified to be distal to hormone receptor/adenylate cyclase coupled responses and proximal to supply of cholesterol for steroidogenesis.