Treatment of refractory hemorrhage with factor XIII in a patient with hemophilia A with inhibitor

An 11‐year‐old male with hemophilia A and a known high‐titer Factor VIII inhibitor was admitted with retroperitoneal hemorrhage. The patient was receiving infusions of recombinant activated Factor VII (rFVIIa) for a recent elbow hemorrhage when retroperitoneal bleeding commenced. Despite increased dosing of rFVIIa and a dose of activated prothrombin complex concentrate (aPCC), he continued to hemorrhage and required several blood transfusions. Factor XIII was administered 1 hour after rFVIIa and the patient demonstrated cessation of bleeding and normalization of clot strength. Factor XIII may act as an adjuvant in effective clot stabilization in patients with hemophilia and inhibitory antibodies. Pediatr Blood Cancer 2013; 60: E23–E25. © 2013 Wiley Periodicals, Inc.     

Autism spectrum disorder in the genetics clinic: a review

Autism spectrum disorders (ASDs) are a heterogeneous group of neurodevelopmental disorders affecting social communication, language and behavior. The underlying cause(s) in a given individual is often elusive, with the exception of clinically recognizable genetic syndromes with readily available molecular diagnosis, such as fragile X syndrome. Clinical geneticists approach patients with ASDs by ruling out known genetic and genomic syndromes, leaving more than 80% of families without a definitive diagnosis and an uncertain risk of recurrence. Advances in microarray technology and next‐generation sequencing are revealing rare variants in genes with important roles in synapse formation, function and maintenance. This review will focus on the clinical approach to ASDs, given the current state of knowledge about their complex genetic architecture.     

Comparative performances of enzyme-linked immunosorbent, western blot, and polymerase chain reaction assays for human T-lymphotropic virus type II infection that is endemic among Indians of the Gran Chaco region of South America

BACKGROUND : Human T-cell lymphoma/leukemia viruses types I and II (HTLV- I and HTLV-II) are related exogenous human retroviruses. The former is definitely pathogenic while disease association with the latter is unclear. There are two subtypes of HTLV-II, A and B. Currently, enzyme- linked immunosorbent assays (ELISAs) based on HTLV-I antigens are used to screen for the presence of HTLV-I and -II antibodies. Confirmation and subtyping are accomplished by Western blot (WB) or ELISAs based on HTLV-I whole viral antigens and/or HTLV-I and HTLV-IIA peptides. The sensitivity and specificity of these serologic assays were compared to those of HTLV-I and-II-specific polymerase chain reaction (PCR) assays in tests on samples from Indians from South America in whom the HTLV- IIB subtype is endemic. STUDY DESIGN AND METHODS : Sera from 246 Gran Chaco Indians were evaluated for HTLV antibodies with the use of four ELISAs (Retrotek HTLV-I; Cambridge Biotech rgp21 enhanced HTLV-I/II; Vironostika HTLV-I/II; and Select HTLV-I/II), and a WB assay. Peripheral blood leukocyte DNA from each Indian was analyzed for HTLV-I or HTLV-II pol DNA via PCR. Fifteen of the PCR-positive samples were further subtyped via cloning and sequencing and/or oligomer restriction. RESULTS : Ninety-seven samples (39%) were positive for HTLV- II by serologic and/or PCR assays. All 15 positive DNA samples that were further analyzed were of the HTLV-IIB subtype and were clustered as a highly conserved phylogenetic group. Comparative analyses indicate that the sensitivity and specificity of the various assays were: PCR, 97 and 100 percent; Retrotek, 70 and 91 percent; Cambridge Biotech, 74 and 96 percent; Vironostika, 73 and 99 percent; Select 72 and 98 percent; and WB, 70 and 100 percent. CONCLUSION : The sensitivities of the tested HTLV serologic assays were comparable. However, the specificity of the Retrotek ELISA was significantly lower than that of the others. When positive, the subtyping assays were very specific. However, PCR assays would seem preferable or to be a necessary adjunct for the sensitive detection of HTLV-IIB infection.     

Targeted disruption of the mouse sphingolipid activator protein gene: a complex phenotype, including severe leukodystrophy and wide-spread storage of multiple sphingolipids

The four established or putative sphingolipid activator proteins derive from a large precursor protein encoded by a single gene. In addition to generating the four sphingolipid activator proteins, the precursor protein is suspected of having functions of its own, as, for example, a lipid binding/transport protein or a neurotrophic factor. The gene also appears to encode the Sertoli cell major sulfated glycoprotein. Sequence similarities have been noted with many other proteins of diverse functions. One patient and a fetus in a single family with a complete defect of this gene due to a mutation in the initiation codon exhibited complex pathological and biochemical abnormalities. Mutant mice homozygous for an inactivated gene of the sphingolipid activator protein precursor exhibit two distinct clinical phenotypes-neonatally fatal and later-onset. The latter develop rapidly progressive neurological signs around 20 days and die by 35-38 days. At 30 days, severe hypomyelination and periodic acid-Schiff-positive materials throughout the nervous system and in abnormal cells in the liver and spleen are the main pathology. Most prominently lactosylceramide, and additionally ceramide, glucosylceramide, galactosylceramide, sulfatide, and globotriaosylceramide are abnormally increased in the brain, liver, kidney, and their catabolism abnormally slow in cultured fibroblasts. Brain gangliosides are generally increased, particularly the monosialogangliosides. The clinical, pathological and biochemical phenotype closely resembles that of the human disease. This model not only allows further clarification of the physiological functions of the four individual sphingolipid activator proteins but also should be useful to explore putative functions of the precursor protein.      

Vertebral osteomyelitis: assessment using MR

Thirty-seven patients who were clinically suspected of having vertebral osteomyelitis were prospectively evaluated with magnetic resonance (MR), radiography, and radionuclide studies. These findings were correlated with the final clinical, microbiologic, or histologic diagnoses. Based on the results of these latter studies, 23 patients were believed to have osteomyelitis. MR examinations consisted of at least a sagittal image (TE = 30 msec, TR = 0.5 sec) and an image obtained at TE = 120 msec, TR = 2-3 sec. All patients underwent radiographic and MR examinations, 36 underwent technetium 99m-HDP bone scanning, and 20 patients underwent gallium 67 scanning. Nineteen patients underwent both bone and gallium scanning. The imaging studies were reviewed independently by investigators blinded to the final diagnoses. MR had a sensitivity of 96%, specificity of 92%, and accuracy of 94%. Combined gallium and bone scan studies (19 cases) had a sensitivity of 90%, specificity of 100%, and accuracy of 94%. Bone scans alone had a sensitivity of 90%, specificity of 78%, and accuracy of 86%. Plain radiographs had a sensitivity of 82%, specificity of 57%, and accuracy of 73%. The MR appearance of vertebral osteomyelitis in this study was characteristic, and MR was as accurate and sensitive as radionuclide scanning in the detection of osteomyelitis.