Intravenous immunoglobulin to prevent myasthenic crisis after thymectomy and other procedures can be omitted in patients with well-controlled myasthenia gravis

Background:

Myasthenic crisis (MC) is a potentially life-threatening complication of myasthenia gravis. Its precipitating factors include surgical procedures, particularly thymectomy. The role of preoperative intravenous immunoglobulin (IVIg) in preventing MC in patients scheduled for thymectomy and other surgery with general anaesthesia is unknown. Our objective was to test the hypothesis that preoperative IVIg is effective in preventing myasthenic crisis in patients with myasthenia gravis scheduled for surgery under general anaesthesia, including thymectomy.

Methods:

A prospective, randomized, double-blind, single-centre study was conducted over a 4-year period. The treatment group received IVIg, 0.4 g/kg/day preoperatively for 5 consecutive days, and the placebo group received saline solution under the same conditions. The two groups were age-matched, with similar functional status, and Myasthenia Gravis Foundation of America class. All patients had well-controlled myasthenia gravis with minimal manifestations before surgery. The primary outcome measured was MC. Intubation times, time in the recovery room, number of postoperative complications, and days of hospitalization were the secondary outcomes measured.

Results:

A total of 47 patients were randomized, 25 to the IVIg group and 22 to placebo. There were 19 men and 28 women, with a mean age of 58.6 years, mean body mass index of 27.8 kg/m², and mean acetylcholine receptor antibodies of 12.9 nmol/l. The mean forced vital capacity was 84.4%. The mean quantitative myasthenia gravis sum score was 6.3. Ten patients (five in each arm) had a history of MC. Thymectomy was performed in 16 patients. Only one patient in the placebo group presented with MC requiring non-invasive ventilation (but no reintubation) for 6 days. Neither differences between groups in the univariate analysis nor risk factors for MC in the multivariate analysis were found.

Conclusions:

Preoperative IVIg to prevent MC does not appear to be justified in well-controlled myasthenia gravis patients. This study provides class I evidence that preparation with IVIg to prevent MC is not necessary in well-controlled myasthenia gravis patients scheduled for surgery with general anaesthesia.

Transthyretin stabilization activity of the catechol-O-methyltransferase inhibitor tolcapone (SOM0226) in hereditary ATTR amyloidosis patients and asymptomatic carriers: proof-of-concept study. Amyloid 2019;26:74-84. [PMID: 31119947 DOI: 10.1080/13506129.2019.1597702]

Objective: To assess the transthyretin (TTR) stabilization activity of tolcapone (SOM0226) in patients with hereditary ATTR amyloidosis, asymptomatic carriers and healthy volunteers. Methods: A phase IIa proof-of-concept trial included two phases separated by a 6-week washout period. Phase A: single 200 mg dose of tolcapone; phase B: three 100 mg doses taken at 4 h intervals. The primary efficacy variable was TTR stabilization. Results: Seventeen subjects were included (wild type, n = 6; mutation TTR Val30Met, n = 11). TTR stabilization was observed in all participants. Two hours after dosing, 82% of participants in phase A and 93% of those in phase B reached a TTR stabilization value of at least 20%. In phase A, there was an increase of 52% in TTR stabilization vs baseline values 2 h after dosing, which decreased to 22.9% at 8 h. In phase B, there was a significant increase of 38.8% in TTR stabilization 2 h after the first 100 mg dose. This difference was maintained after 10 h and decreased after 24 h. No serious adverse events were observed. Conclusions: The ability of tolcapone for stabilizing TTR supports further development and repositioning of the drug for the treatment of ATTR amyloidosis. EudraCT trial number: 2014-001586-27 ClinicalTrials.gov Identifier: NCT02191826.

Midodrine and albumin for prevention of complications in patients with cirrhosis awaiting liver transplantation. A randomized placebo-controlled trial

BACKGROUND & AIMS

Patients with decompensated cirrhosis on the waiting list for liver transplantation (LT) commonly develop complications that may preclude them from reaching LT. Circulatory dysfunction leading to effective arterial hypovolemia and activation of vasoconstrictor systems is a key factor in the pathophysiology of complications of cirrhosis. The aim of this study was to investigate whether treatment with midodrine, an alpha-adrenergic vasoconstrictor, together with intravenous albumin improves circulatory dysfunction and prevents complications of cirrhosis in patients awaiting LT.

METHODS

A multicenter, randomized, double-blind, placebo-controlled trial (NCT00839358) was conducted, including 196 consecutive patients with cirrhosis and ascites awaiting LT. Patients were randomly assigned to receive midodrine (15-30 mg/day) and albumin (40 g/15 days) or matching placebos for one year, until LT or drop-off from inclusion on the waiting list. The primary endpoint was incidence of any complication (renal failure, hyponatremia, infections, hepatic encephalopathy or gastrointestinal bleeding). Secondary endpoints were mortality, activity of endogenous vasoconstrictor systems and plasma cytokine levels.

RESULTS

There were no significant differences between both groups in the probability of developing complications of cirrhosis during follow-up (p = 0.402) or one-year mortality (p = 0.527). Treatment with midodrine and albumin was associated with a slight but significant decrease in plasma renin activity and aldosterone compared to placebo (renin -4.3 vs. 0.1 ng/ml.h, p < 0.001; aldosterone -38 vs. 6 ng/dl, p = 0.02, at week 48 vs. baseline). Plasma norepinephrine only decreased slightly at week 4. Neither arterial pressure nor plasma cytokine levels changed significantly.

CONCLUSIONS

In patients with cirrhosis awaiting LT, treatment with midodrine and albumin, at the doses used in this study, slightly suppressed the activity of vasoconstrictor systems, but did not prevent complications of cirrhosis or improve survival.

LAY SUMMARY

Patients with cirrhosis who are on the liver transplant waiting list often develop complications which prevent them from receiving a transplant. Circulatory dysfunction is a key factor behind a number of complications. This study was aimed at investigating whether treating patients with midodrine (a vasoconstrictor) and albumin would improve circulatory dysfunction and prevent complications. This combined treatment, at least at the doses administered in this study, did not prevent the complications of cirrhosis or improve the survival of these patients.

Impact of ornithine phenylacetate (OCR-002) in lowering plasma ammonia after upper gastrointestinal bleeding in cirrhotic patients

BACKGROUND

Ornithine phenylacetate (OP) has been proven effective in lowering ammonia plasma levels in animals, and to be well tolerated in cirrhotic patients. A trial to assess OP efficacy in lowering plasma ammonia levels versus placebo in cirrhotic patients after an upper gastrointestinal bleeding was performed. The primary outcome was a decrease in venous plasma ammonia at 24 hours.

METHODS

A total of 38 consecutive cirrhotic patients were enrolled within 24 hours of an upper gastrointestinal bleed. Patients were randomized (1:1) to receive OP (10 g/day) or glucosaline for 5 days.

RESULTS

The primary outcome was not achieved. A progressive decrease in ammonia was observed in both groups, being slightly greater in the OP group, with significant differences only at 120 hours. The subanalysis according to Child-Pugh score showed a statistically significant ammonia decrease in Child-Pugh C-treated patients at 36 hours, as well as in the time-normalized area under the curve (TN-AUC) 0-120 hours in the OP group [40.16 μmol/l (37.7-42.6); median (interquartile range) (IQR)] versus placebo group [65.5 μmol/l (54-126);p = 0.036]. A decrease in plasma glutamine levels was observed in the treated group compared with the placebo group, and was associated with the appearance of phenylacetylglutamine in urine. Adverse-event frequency was similar in both groups. No differences in hepatic encephalopathy incidence were observed.

CONCLUSIONS

OP failed to significantly decrease plasma ammonia at the given doses (10 g/day). Higher doses of OP might be required in Child-Pugh A and B patients. OP appeared well tolerated.

Intrapleural Fibrinolysis with Urokinase Versus Alteplase in Complicated Parapneumonic Pleural Effusions and Empyemas: A Prospective Randomized Study

BACKGROUND

Pleurofibrinolysis has been reported to be potentially beneficial in the management of complicated parapneumonic effusions (CPPE) and empyemas in the adult population.

METHODS

Prospective, controlled, randomized, and double-blind study, to evaluate intrapleural alteplase 10 mg (initially 20 mg was considered but bleeding events forced dose reduction) versus 100,000 UI urokinase every 24 h for a maximum of 6 days in patients with CPPE or empyemas. The primary aim was to evaluate the success rate of each fibrinolytic agent at 3 and 6 days. Success of therapy was defined as the presence of both clinical and radiological improvement, making additional fibrinolytic doses unnecessary, and eventually leading to resolution. Secondary outcomes included the safety profile of intrapleural fibrinolytics, referral for surgery, length of hospital stay, and mortality.

RESULTS

A total of 99 patients were included, of whom 51 received alteplase and 48 urokinase. Success rates for urokinase and alteplase at 3 and 6 days were not significantly different, but when only the subgroup of CPPE was considered, urokinase resulted in a high proportion of cures. There were no differences in mortality or surgical need (overall, 3 %). Five (28 %) patients receiving 20 mg of alteplase and 4 (12 %) receiving 10 mg presented serious bleeding events.

CONCLUSIONS

If intrapleural fibrinolytics are intended to be used, urokinase may be more effective than alteplase in patients with non-purulent CPPE and have a lower rate of adverse events.

Risk of hyperkalemia in patients with moderate chronic kidney disease initiating angiotensin converting enzyme inhibitors or angiotensin receptor blockers: a randomized study

Background

Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers are renoprotective but both may increase serum potassium concentrations in patients with chronic kidney disease (CKD). The proportion of affected patients, the optimum follow-up period and whether there are differences between drugs in the development of this complication remain to be ascertained.

Methods

In a randomized, double-blind, phase IV, controlled, crossover study we recruited 30 patients with stage 3 CKD under restrictive eligibility criteria and strict dietary control. With the exception of withdrawals, each patient was treated with olmesartan and enalapril separately for 3 months each, with a 1-week wash-out period between treatments. Patients were clinically assessed on 10 occasions via measurements of serum and urine samples. We used the Cochran–Mantel–Haenszel statistics for comparison of categorical data between groups. Comparisons were also made using independent two-sample t-tests and Welch’s t-test. Analysis of variance (ANOVA) was performed when necessary. We used either a Mann–Whitney or Kruskal-Wallis test if the distribution was not normal or the variance not homogeneous.

Results

Enalapril and olmesartan increased serum potassium levels similarly (0.3 mmol/L and 0.24 mmol/L respectively). The percentage of patients presenting hyperkalemia higher than 5 mmol/L did not differ between treatments: 37% for olmesartan and 40% for enalapril. The mean e-GFR ranged 46.3 to 48.59 ml/mint/1.73 m² in those treated with olmesartan and 46.8 to 48.3 ml/mint/1.73 m² in those with enalapril and remained unchanged at the end of the study. The decreases in microalbuminuria were also similar (23% in olmesartan and 29% in enalapril patients) in the 4 weeks time point. The percentage of patients presenting hyperkalemia, even after a two month period, did not differ between treatments. There were no appreciable changes in sodium and potassium urinary excretion.

Conclusions

Disturbances in potassium balance upon treatment with either olmesartan or enalapril are frequent and without differences between groups. The follow-up of these patients should include control of potassium levels, at least after the first week and the first and second month after initiating treatment.

Trial registration

The trial EudraCT “2008-002191-98”.

Positive outcomes influence the rate and time to publication, but not the impact factor of publications of clinical trial results

OBJECTIVES

Publication bias may affect the validity of evidence based medical decisions. The aim of this study is to assess whether research outcomes affect the dissemination of clinical trial findings, in terms of rate, time to publication, and impact factor of journal publications.

METHODS AND FINDINGS

All drug-evaluating clinical trials submitted to and approved by a general hospital ethics committee between 1997 and 2004 were prospectively followed to analyze their fate and publication. Published articles were identified by searching Pubmed and other electronic databases. Clinical study final reports submitted to the ethics committee, final reports synopses available online and meeting abstracts were also considered as sources of study results. Study outcomes were classified as positive (when statistical significance favoring experimental drug was achieved), negative (when no statistical significance was achieved or it favored control drug) and descriptive (for non-controlled studies). Time to publication was defined as time from study closure to publication. A survival analysis was performed using a Cox regression model to analyze time to publication. Journal impact factors of identified publications were recorded. Publication rate was 48·4% (380/785). Study results were identified for 68·9% of all completed clinical trials (541/785). Publication rate was 84·9% (180/212) for studies with results classified as positive and 68·9% (128/186) for studies with results classified as negative (p<0·001). Median time to publication was 2·09 years (IC95 1·61-2·56) for studies with results classified as positive and 3·21 years (IC95 2·69-3·70) for studies with results classified as negative (hazard ratio 1·99 (IC95 1·55-2·55). No differences were found in publication impact factor between positive (median 6·308, interquartile range: 3·141-28·409) and negative result studies (median 8·266, interquartile range: 4·135-17·157).

CONCLUSIONS

Clinical trials with positive outcomes have significantly higher rates and shorter times to publication than those with negative results. However, no differences have been found in terms of impact factor.

Consent in clinical trials: what do patients know?

OBJECTIVE

To assess participants' knowledge of key aspects about the clinical trials in which they are enrolled, describe the consent process, and assess the importance that investigators give to various aspects of trial information when verbally informing candidates.

DESIGN

Prospective study based on a structured questionnaire interview of participants within 3 months after trial enrollment and an anonymous questionnaire sent to clinical trial investigators.

SUBJECTS

A total of 140 participants included in 40 clinical trials were interviewed, and 51 investigators answered the questionnaire.

RESULTS

The formal steps to obtain informed consent were usually carried out. Participants were aware of the purpose of the trial and the right to discontinue participation, but only 23% knew that treatment was randomly allocated, 57% knew they might receive a placebo, and 42% was aware that adverse effects could occur. Patients who had read the information sheet had better knowledge of most aspects, except for the risk of adverse effects. The investigators considered that compensation, insurance coverage, possibility of receiving a placebo, and treatment allocation were the least important aspects of the trial when informing candidates for participation.

CONCLUSIONS

Although the formal steps for obtaining informed consent were usually carried out, a relevant percentage of patients included in clinical trials were unaware of important aspects of their participation. Patients showed more limited knowledge about the same points that investigators considered less important when informing potential participants. Deferring signature on the consent form and encouraging reading of the information sheet may improve participants' knowledge about clinical trials.

Modulating Effects of Intravenous Immunoglobulins on Serum Cytokine Levels in Patients with Primary Hypogammaglobulinemia

BACKGROUND

Intravenous immunoglobulins (IVIG) have usually been administered for replacement therapy of humoral immunodeficiencies, but their use in treating other disorders with an immune pathogenesis is increasing. The exact mechanism of action by which IVIG are of benefit in such diseases is complex and only partly understood. One of the proposed mechanisms of action is the modulation of cytokine release.

METHODS

We selected 29 patients with primary hypogammaglobulinemia (common variable immunodeficiency), receiving long-term substitutive therapy with IVIG, and 14 healthy blood donors as a control group. Blood samples were then taken before and 1 hour after finishing the IVIG infusion. Only one blood sample was obtained from the healthy controls. The cytokines studied were interleukin (IL)-1 beta, IL-1 receptor antagonist (IL-1Ra), IL-2, IL-6, IL-8, tumor necrosis factor (TNF)-alpha, and interferon (IFN)-gamma.

RESULTS

Patients with primary hypogammaglobulinemia showed significantly higher serum levels of IL-6, IL-8, IL-1Ra, and TNF alpha than healthy controls. IVIG infusion significantly increased serum concentration levels of IL-6, IL-8, IL-1Ra, and TNF alpha. No significant variation was observed in serum levels of IL-beta, IFN gamma, or IL-2 after IVIG infusion. Age, IVIG commercial preparation, and IVIG dose did not influence cytokine serum levels. Moreover, a significant correlation was observed between serum level variations of IL-1Ra and TNF alpha, as well as an associative trend between maximum changes in IL-6 and IL-8 concentrations.

CONCLUSIONS

IVIG administration significantly alters the serum pattern of selected cytokines, which might explain, at least in part, the mechanism of action of IVIG in autoimmune or inflammatory disorders.

Inhaled tobramycin in non-cystic fibrosis patients with bronchiectasis and chronic bronchial infection with Pseudomonas aeruginosa

BACKGROUND

Non-cystic fibrosis (CF) patients with bronchiectasis usually develop chronic bronchial infection with Pseudomonas aeruginosa (PA) that is related to worsening lung function and increased morbidity and mortality.

OBJECTIVE

To determine whether direct aerosol delivery of tobramycin to the lower airways may control infection and produce only low systemic toxicity.

METHODS

A double-blind, placebo-controlled crossover trial involving 30 patients was conducted to determine the clinical effectiveness and safety of 6-month tobramycin inhalation therapy. Patients received 300 mg of aerosolized tobramycin or placebo twice daily in 2 cycles, each for 6 months, with a one-month washout period. The number of exacerbations, number of hospital admissions, number of hospital admission days, antibiotic use, pulmonary function, quality of life, tobramycin toxicity, density of PA in sputum, emergence of bacterial resistance, and emergence of other opportunistic bacteria were recorded.

RESULTS

The number of admissions and days of admission (mean +/- SD) during the tobramycin period (0.15 +/- 0.37 and 2.05 +/- 5.03) were lower than those during the placebo period (0.75 +/-1.16 and 12.65 +/- 21.8) (p < 0.047). A decrease in PA density in sputum was associated with tobramycin administration in the analysis of the first 6-month cycle (p = 0.038). No significant differences were observed in the number of exacerbations, antibiotic use, pulmonary function, and quality of life. The emergence of bacterial resistance and other bacteria did not differ between the 2 periods of study. Inhaled tobramycin was associated with bronchospasm in 3 patients, but not with detectable ototoxicity or nephrotoxicity.

CONCLUSIONS

Aerosol administration of high-dose tobramycin in non-CF bronchiectatic patients for endobronchial infection with PA appears to be safe and decreases the risk of hospitalization and PA density in sputum. Nevertheless, pulmonary function and quality of life are not improved, and the risk of bronchospasm is appreciable.