Laboratory tests for disorders of complement and complement regulatory proteins

The complement pathway is a cascade of proteases that is involved in immune surveillance and innate immunity, as well as adaptive immunity. Dysfunction of the complement cascade may be mediated by aberrations in the pathways of activation, complement regulatory proteins, or complement deficiencies, and has been linked to a number of hematologic disorders, including paroxysmal noctural hemoglobinuria (PNH), hereditary angioedema (HAE), and atypical hemolytic‐uremic syndrome (aHUS). Here, current laboratory tests for disorders of the complement pathway are reviewed, and their utility and limitations in hematologic disorders and systemic diseases are discussed. Current therapeutic advances targeting the complement pathway in treatment of complement‐mediated hematologic disorders are also reviewed. Am. J. Hematol. 90:1180–1186, 2015. © 2015 Wiley Periodicals, Inc.     

A Novel Frameshift Mutation in TWIST2 Gene Causing Setleis Syndrome

The authors report on a child with Setleis syndrome (OMIM 227260). She is born to a consanguineous couple with bitemporal scar like defects resembling forceps marks. She had other classical features resembling autosomal recessive Setleis syndrome. The authors identified a novel homozygous deletion of a single nucleotide (c.91delC) in TWIST2 gene leading to the premature truncation of protein (p.R31GfsX71). Umbilical hernia and genital anomalies are being reported for the first time with this condition. This is the fourth mutation proven family of Setleis syndrome.     

Cardiovascular Complications and Their Association With Mortality in Patients With Thrombotic Thrombocytopenic Purpura

BackgroundDespite widespread availability of plasmapheresis, the mortality in thrombotic thrombocytopenic purpura remains high. Cardiovascular complications have been reported as an important cause of morbidity in these patients. The burden and prognostic implications of these complications have not been well studied. We analyzed the rates of cardiovascular complications in thrombotic thrombocytopenic purpura, temporal trends, and studied its impact on in-hospital mortality.MethodsWe analyzed the National Inpatient Sample (NIS) from January 2005 to September 2015 to identify adult patients with thrombotic thrombocytopenic purpura. This group was further refined by excluding patients who did not receive therapeutic plasmapheresis, and other conditions that can mimic thrombotic thrombocytopenic purpura. We identified the age- and sex-stratified rates of cardiac arrhythmias, cardiac conduction system disorders, heart failure, acute coronary syndrome, myocarditis, pericarditis, takotsubo cardiomyopathy, cardiogenic shock, cardiac arrest, and stroke. We also compared in-hospital mortality with and without cardiovascular complications.ResultsAmong 15,054 thrombotic thrombocytopenic purpura hospitalizations (mean age 46.4 years, 69% in the 18- to 54-age group, 66.2% women, and 42.9% white), a cardiovascular complication was observed in 3802 (25.3%) hospitalizations. The following cardiovascular complications were identified: stroke (10.4%), heart failure (8.3%), acute coronary syndrome (6.4%), atrial tachyarrhythmia (5.9%), ventricular tachyarrhythmia (2.0%), cardiogenic shock (0.5%), takotsubo cardiomyopathy (0.1%), atrioventricular block (0.2%), myocarditis or pericarditis (0.3), and cardiac arrest (1.9%). Rates of several cardiovascular complications were significantly higher in patients 55 years or older compared to a younger age group, whereas males had higher rates of acute coronary syndrome and tachyarrhythmias compared to females. Overall, the cardiovascular complication rate was stable during the study period. The presence of a major cardiovascular complication was associated with a significantly higher in-hospital mortality (19.7%) as compared with no major cardiovascular complication (4.1%) (adjusted odds ratio 2.09, 95% confidence interval 1.41-3.09, P <0.001). Results were generally consistent in age and sex subgroups.ConclusionCardiovascular complications were frequently observed at a rate of 1 in 4 in patients hospitalized for thrombotic thrombocytopenic purpura and were associated with substantially higher in-hospital mortality. These findings underscore the need to promptly identify and treat these complications to improve outcomes.