Safety in transfusion practices. Red cell compatibility testing issues.

Pretransfusion compatibility testing, if performed properly, helps to maximize the effectiveness of transfusion therapy and to minimize the risk of hemolytic transfusion reactions. Each laboratory should select the procedures and protocols that are best suited to meet their patient care and institutional needs. Quality assessment monitoring of the elements of compatibility testing helps to ensure a high level of safety for patients receiving transfusion therapy.     

ISFG: Recommendations on biostatistics in paternity testing

The Paternity Testing Commission (PTC) of the International Society for Forensic Genetics has taken up the task of establishing the biostatistical recommendations in accordance with the ISO 17025 standards and a previous set of ISFG recommendations specific to the genetic investigations in paternity cases. In the initial set, the PTC recommended that biostatistical evaluations of paternity are based on a likelihood ratio principle – yielding the paternity index, PI. Here, we have made five supplementary biostatistical recommendations. The first recommendation clarifies and defines basic concepts of genetic hypotheses and calculation concerns needed to produce valid PIs. The second and third recommendations address issues associated with population genetics (allele probabilities, Y-chromosome markers, mtDNA, and population substructuring) and special circumstances (deficiency/reconstruction and immigration cases), respectively. The fourth recommendation considers strategies regarding genetic evidence against paternity. The fifth recommendation covers necessary documentation, reporting details and assumptions underlying calculations. The PTC strongly suggests that these recommendations should be adopted by all laboratories involved in paternity testing as the basis for their biostatistical analysis.     

Activation of the Complement, Coagulation, Fibrinolytic and Kallikrein–Kinin Systems During Attacks of Hereditary Angioedema

Five patients with hereditary angioedema (HAE) were studied during attacks and remission as were healthy controls. The high levels of C1/C1-INH complexes, low C4 and high ratio C4 activation products (C4bc)/C4 also differed significantly during remission compared to controls.During attacks C4bc/C4 increased (922–2007; P =0.022, remission versus attacks, median values throughout), C2 and CH50 dropped (111–31%; P =0.043 and 110–36%; P =0.016, respectively), TCC (C5b-9) increased (0.88–1.23 AU/ml; P =0.028). Cleavage of HK increased to be almost complete during attacks (20–90%; P =0.009). While factor XIa/serpin-complexes did not increase, a more than twofold rise in thrombin/antithrombin-complexes (0.20–0.50 μg/l; P =0.009) and in plasmin/alpha-2-antiplasmin-complexes (7.3–17 nmol/l; P =0.028) was observed. For the first time cascade activation in HAE was studied simultaneously, and corroborates that attacks lead to activation of the kallikrein-kinin system, fibrinolysis and early part of the classical complement pathway. In addition, the authors present novel data of terminal complement and coagulation activation, the latter apparently not via FXIa.     

Phenotypic variability of a distinct deletion in McLeod syndrome

The X‐linked McLeod neuroacanthocytosis syndrome strongly resembles Huntington's disease and has been reported in various countries world‐wide. Herein, we report two Chilean brothers with predominant psychiatric features at disease onset including schizophrenia‐like psychosis and obsessive compulsive disorder. Molecular genetic analysis revealed a small deletion in the XK gene (938‐942delCTCTA), which has been already described in a North American patient of Anglo‐Saxon descent and a Japanese family, presenting with seizures, muscle atrophy or chorea yet absence of psychiatric features. These findings argue against a founder effect and indicate a profound phenotypic variability associated with the 938‐942delCTCTA deletion. Our report supports the inclusion of McLeod syndrome in the differential diagnosis of Huntington's disease as well as acute psychosis in male subjects. © 2007 Movement Disorder Society