Childhood-onset systemic lupus erythematosus in Singapore: clinical phenotypes, disease activity, damage, and autoantibody profiles.

Childhood-onset systemic lupus erythematosus (cSLE) is a multisystem autoimmune disease characterized by immune dysregulation affecting patients less than 18 years old. One-fifth of SLE cases are diagnosed during childhood. cSLE presents differently from adults and has a more severe and aggressive course. We describe the clinical and antibody profiles in our cSLE Singapore cohort. All cSLE patients who satisfied the 1997 American College of Rheumatology diagnostic criteria were captured in our lupus registry from January 2009 to January 2014. Data including demographic, cumulative clinical, serologic data, and damage indices were collected. Adjusted mean SLEDAI-2K (AMS) was used to summarize disease activity over multiple visits. Cluster analysis using non-hierarchical K-means procedure was performed on eight selected antibodies. The 64 patients (female:male ratio 5:1; Chinese 45.3%, Malay 28.1%, Indian 9.4%, and other races 17.2%) had a mean onset age of 11.5 years (range 2.1-16.7) and mean age at diagnosis was 11.9 years (range 2.6-18.0). Our study demonstrated differences in clinical manifestations for which hematologic involvement was the most common manifestation with less renal disease and uncommon neurologic manifestation as compared to other cSLE cohorts reported in our region. Antibody clusters were identified in our cohort but their clinical association/discrimination and outcome prediction required further validation study. Outcomes of our cohort in regard to disease activity after therapy and organ damages were comparable if not better to other cSLE cohorts elsewhere. Steroid-related damage, including symptomatic multifocal avascular necrosis and cataract, were not uncommon locally. Infection remains the major cause of death for the continent. Nevertheless, the five year survival rate of our cohort (98.4%) was high.

True-positive exercise electrocardiogram/false-negative thallium-201 scintigram: a proposal of a mechanism for the paradox.

A 72-year-old man with exertional angina had a strongly positive exercise electrocardiogram (EECG) with a negative thallium-201 myocardial perfusion scintigram (Tl). Arteriography revealed triple-vessel coronary artery disease, for which he underwent aortocoronary bypass grafting. Repeat EECG was negative, and it was again associated with a negative Tl. The false-negative Tl on the first test was felt to be due to a rare phenomenon of homogeneously distributed reversible exercise-induced myocardial ischemia, leading to a uniform radiotracer count density. The even distribution of ischemia would also be expected to render a false-negative EECG, due to electrocardiographic cancellation, and this is frequently the case. However, in the patient presented herein, we propose that the ischemic cardiac apex rendered the EECG strongly positive because its position was not opposed by an ischemic muscular region, and thus an uncancelled ischemic ST-segment vector was generated. This hypothesis is supported by our recent work showing the unique role of the ischemic apex (among all the other myocardial territories) in rendering the EECG positive.

Elevation of serum cardiac troponin I in noncardiac and cardiac diseases other than acute coronary syndromes.

This study evaluated the role of serum cardiac troponin I as a biochemical marker for the diagnosis of acute coronary syndromes in the presence of noncardiac diseases. Diagnostic characteristics were examined in 102 consecutive patients who were found to have serum cardiac troponin I levels higher than the upper reference limit of 0.6 ng/mL. Of 102 patients with cardiac troponin I levels of >0.6 ng/mL, 35 did not have the final diagnoses of acute coronary syndromes (myocardial infarction or unstable angina) but had various other final diagnoses, including nonischemic dilated cardiomyopathy, muscular disorders, central nervous system disorders, HIV disease, chronic renal failure, sepsis, lung diseases, and endocrine disorders. The mean value of serum cardiac troponin I in the patients with diseases other than acute coronary syndromes was significantly lesser than in those with acute coronary syndromes (2.0+/-1.9 [SD] v. 24.7+/-28.2 ng/mL; P<.0001). There were significantly fewer histories of chest pain and prior myocardial infarction in patients with diseases other than acute coronary syndromes than in those with acute coronary syndromes (history of chest pain, 3 v. 48 patients [P<.001]; history of prior myocardial infarction, 0 v. 30 patients [P<.001]). In conclusion, elevated serum levels of cardiac troponin I, especially in the lower ranges, should be interpreted with caution, particularly in patients suffering from acute illnesses who lack other diagnostic features suggestive of acute coronary ischemic events.

Torsades de pointes: a case with multiple variables.

Torsades de pointes is a polymorphic ventricular tachycardia that displays a unique electrocardiographic feature of twisting of the mean electrical axis of QRS complexes around an isoelectric line on the surface electrocardiogram. It is associated with long QT syndrome and has many precipitating mechanisms, etiologic factors, and treatment options. This report presents a case of torsades de pointes that was precipitated by multiple factors and required many treatment modalities. The patient in this case exhibited features of both congenital and acquired types of long QT syndrome.

Increased regional and transmyocardial dispersion of ventricular repolarization in end-stage renal disease.

BACKGROUND: Approximately half of patients with end-stage renal disease die because of cardiac disease, and ventricular arrhythmias are the common terminal events. Increased dispersion of the repolarization phase of the myocardial action potential can predispose patients to ventricular tachycardia and fibrillation causing cardiac death. OBJECTIVE: To determine the existence of increased regional and transmyocardial dispersion of ventricular repolarization in end-stage renal disease. STUDY DESIGN: Case-control prospective study. PATIENTS AND METHODS: The QT dispersion and the interval between the peak of the T wave (Tp) and the end of the T wave (Te) on a surface electrocardiogram represent regional and transmyocardial dispersion in ventricular repolarization, respectively. The prehemodialysis QT dispersions and Tp-Te intervals of 94 consecutive patients with end-stage renal disease were determined and compared with those of age- and sex-matched healthy controls. RESULTS: Both the QT and the QTc dispersion were significantly higher in the end-stage renal disease group than in the control group (QT dispersion 46 +/- 17 ms [mean +/- SD] versus 26 +/- 16 ms, P < 0.001; QTc dispersion 51 +/- 20 ms versus 30 +/- 20 ms, P < 0.001). Similarly, both the corrected average Tp-Te and the corrected maximum Tp-Te intervals were significantly higher in the end-stage renal disease group than in the control group (corrected average Tp-Te interval 99 +/- 19 ms versus 87 +/- 19 ms, P = 0.023; corrected maximum Tp-Te interval 114 +/- 23 ms versus 103 +/- 23 ms, P = 0.023). CONCLUSIONS: Increased regional and transmyocardial dispersion of ventricular repolarization in end-stage renal disease was demonstrated. This increased dispersion may be a contributory factor in the high cardiac mortality in patients with end-stage renal disease.

Specificity of cardiac troponin I and creatine kinase-MB isoenzyme in asymptomatic long-term hemodialysis patients and effect of hemodialysis on these cardiac markers.

OBJECTIVES: The objectives of this study were: (1) to evaluate the specificity of cardiac troponin I and creatine kinase-MB isoenzyme in ambulatory asymptomatic chronic renal failure patients on long-term hemodialysis, and (2) to evaluate the effect of hemodialysis on the serum levels of cardiac troponin I and creatine kinase-MB isoenzyme. METHODS: One hundred and forty-four consecutive ambulatory asymptomatic chronic renal failure patients on hemodialysis for a minimum of 1 year were evaluated clinically. Serum cardiac troponin I and creatine kinase-MB isoenzyme levels were measured with specific monoclonal antibodies before and after dialysis using ACCESS Troponin I and ACCESS CK-MB assays. RESULTS: The specificity of serum cardiac troponin I was 83% with a cutoff level of 0.03 ng/ml, which is an expected level for healthy population, but it rose to 100% with a cutoff level of 0.15 ng/ml, which is a reference level for patients with acute myocardial infarction. Twenty-four (17%) patients had borderline elevation in cardiac troponin I (>0.03 to <0.15 ng/ml). A history of angina pectoris was more common in the borderline-elevated cardiac troponin I subgroup. In 28% of the patients, serum creatine kinase-MB isoenzyme levels were increased with a specificity of 72% at a cutoff level of 4 ng/ml, which is the upper limit of normal, but the specificity rose to 98% by increasing the cutoff level value to 10 ng/ml. There were no statistically significant differences in serum levels of cardiac troponin I and creatine kinase-MB isoenzyme before and after dialysis. CONCLUSIONS: Cardiac troponin I is highly specific in ambulatory asymptomatic chronic renal failure patients on long-term hemodialysis; borderline elevations in cardiac troponin I may represent microinjury to the myocardium. A serum level of creatine kinase-MB isoenzyme >2.5 times of the normal upper limit may be highly specific in this patient population. Hemodialysis per se does not significantly change the serum levels of cardiac troponin I and creatine kinase-MB isoenzyme.

Active immunization against tetanus III. Results of a five year study.

This is the first time in Burma that tetanus toxoids (purified and adsorbed) have been tested in over 250 non-immune adult volunteers and studied for a period of nearly five years. The safety and efficacy of these toxoids have been assessed by immunological, statistical and clinical methods. Both toxoids were found to be safe. The adsorbed toxoid was far superior to the fluid toxoid as an immunizing agent and optimum immunization regimens are proposed and presented.

Pre-exposure prophylaxis of humans against rabies: I. Studies on personnel at the Burma Pharmaceutical Industry.

This is the first time in Burma where personnel at risk against rabies have been pre-immunized and the effectiveness of such a procedure has been studied for nearly two years. The first batch of lyophilized, Semple-type, beta propiolactone inactivated anti rabies vaccine produced by the Burma Pharmaceutical Industry (B.P.I.) was used to immunize 55 B.P.I. workers previously unexposed to rabies and with no history of rabies vaccination. Three doses of 0.25 ml of the vaccine were given intradermally at one week intervals. Booster doses were given on the 98th, 392nd and 592nd day after the first dose. Blood samples were taken and serum neutralization tests were performed at varying time intervals after basic immunization and booster doses. Satisfactory antibody responses were obtained. The course of immunological response is presented and discussed.