Platelet and TRALI: From blood component to organism

Even though used systematically with leukocyte reduction, platelet transfusions still cause adverse reactions in recipients. They include Transfusion-Related Acute Lung Injury (TRALI), respiratory distress that occurs within six hours of the transfusion. The pathophysiology of this transfusion complication brings complex cellular communication into play. The role, particularly inflammatory, played by blood platelets in TRALI pathophysiology has been demonstrated, but is still under debate. Blood platelets play a role in inflammation, particularly via the CD40/CD40L (sCD40L) immunomodulator complex. In this study, we examine in particular the specific involvement of the CD40/CD40L (sCD40L) complex in the inflammatory pathogenesis of TRALI. This molecular complex could be a major target in a TRALI prevention strategy. Improving the conditions in which the platelet concentrates (PC) are prepared and stored would contribute to controlling partly the risks of non-immune TRALI.     

Cornea bank of Lyon: from quality diagnosis to ISO 9001 certification]

The tissue and cell bank of the HCL (Hospices Civils de Lyon) has, since 10 June 1999, consisted of two sections with related activities: cell culture for the Skin Substitutes Laboratory (Laboratoire des Substituts Cutanés, LSC) and preservation of corneas at 31 degrees C for the Cornea Bank. As the LSC had been ISO 9001 certified since March 1997 our aim, since merger, was to raise the Cornea Bank to the same level of quality as the LSC, so as to coincide with the renewal of the LSC certificate in February 2000. The methods we used (project, quality control, analysis and process optimization) led us to receive official certification only nine months after the merger. The procedure started with a program of quality control at the Cornea Bank from February 1999 onwards, in order to list the work and equipment required, evaluate its documentation system and what was needed to incorporate this new activity into the existing system of quality assurance at the LSC. On the 7th March 2000, the Tissue and Cell Bank of the HCL obtained an ISO 9001 certificate for its combined functions. As well as achieving our objectives and the strong points highlighted by the auditor during the renewal process, this quality assessment revealed many advantages: improvements in the conservation of corneas, economies in staff replacement and reductions in both the cost of maintaining quality, the cost of the corneas themselves, etc. The decree 'Banque' no. 99-741 of 30th August 1999, which put in place the system of authorization of tissue banks in France, demands quality control. Our application for certification which started in early 1999 had anticipated this regulation. This helped us enormously when compiling the dossier accompanying the official request and was an essential element in obtaining the favourable response of the ASSAPS on 21 June 2000.     

Cystinuria: from diagnosis to follow-up

Cystinuria is an autosomal recessive disorder characterized by an impaired transport of cystine and dibasic aminoacids, lysine, arginine and ornithine in the proximal renal tubule and in the epithelial cells of the gastrointestinal tract. Recurrent cystine nephrolithiasis is the main clinical feature. Mutations in SLC3A1 and/or SLC7A9 genes, which are encoding respectively the rBAT and the b(0,+)AT proteins of the amino acid transport system, are responsible of this disorder thus inducing a high dibasic amino acid excretion. Diagnostic is based on stone analysis by infrared spectroscopy or microscopic examination of urine which may reveal typical cystine crystals. Quantitative cystine excretion, which may be assessed by aminoacid chromatography, is higher in cystinic patients. Molecular approach can identify mutations which are responsible of this pathology. Medical treatment is mainly based on hydratation and urine alkalinisation, with the addition of thiol derivative only in refractory cases. Follow-up based on pH and specific gravity determination in urine samples and cystine crystal volume measurement are used to optimally monitor the medical treatment of cystinuric patients. Even with medical management, long-term outcome is poor due to insufficient efficacy and low patient compliance. Many patients suffer from renal insufficiency as a result of recurrent stone formation and repeated surgical procedures.     

Prenatal diagnosis as a method of prevention of congenital and hereditary diseases]

The program of the prevention of congenital and hereditary diseases with the aid of prenatal diagnosis includes a complex of different methods: ultrasonography, invasive procedures made at different times of pregnancy, obstetrical monitoring, immunochemical blood tests, fetal cytogenetic analysis, pathological, anatomical, and syndromological studies in abortuses. Emphasis is laid on the use of the data on ultrasound screening of the pregnant and screening of the mother's blood for some factors that form a group of women at a greater genetic risk, who require prenatal diagnosis. The efficacy of the preventive measures can be enhanced with combined use of instrumental, obstetrical and laboratory research methods. The establishment of the correct and early diagnosis may, on the one hand, remove the tension and concern in the family; on the other hand, it may prevent bearing a sick child and provide the married couple with a based genetic counselling about progeny.     

Malignant effusions: from diagnosis to biology

Serous effusions are a frequently encountered clinical manifestation of metastatic disease, with breast, ovarian, and lung carcinomas and malignant mesothelioma (MM) leading the list. Recently, extensive research has resulted in expansion of the antibody panel that is available for effusion diagnosis, thereby reducing the risk for error. Despite this progress, relatively little has been done in way of understanding the biology of cancer cells in effusions, especially those of nonovarian origin. The diagnosis of a malignant effusion signifies disease progression and is associated with a worse prognosis regardless of the tumor site of origin. However, survival is much more variable with ovarian cancer compared with other tumors. Furthermore, cancer cells of different origins differ considerably in their biology and have unique phenotypic and genotypic characteristics. This review summarizes the current knowledge in this field and presents a model for the study of tumor metastasis and disease progression, through large comparative studies of malignant cells in effusions, primary tumors, and solid metastases. The case also is made for potential applications of this rapidly evolving body of knowledge in the diagnosis, classification, and prediction of biological behavior of processes resulting in cryptic effusions at the clinical level.     

Secondary stroke prevention: from guidelines to clinical practice

Stroke remains a leading cause of mortality and is associated with substantial morbidity in the United States. The majority of strokes are of ischemic origin, with an atherothrombotic trigger, and the clinical manifestation of atherothrombosis depends on the affected vascular site. The systemic nature of atherosclerosis means that stroke patients are at increased risk of ischemic events in several vascular beds, including cerebral, coronary and peripheral sites. Because stroke patients are at heightened risk of more ischemic events, secondary prevention is an important therapeutic goal. Recently, the American Heart Association and its division, the American Stroke Association, released new evidence-based guidelines for secondary stroke prevention in patients with ischemic stroke or transient ischemic attack. The new guidelines emphasize an individualized, patient-oriented approach to treatment based on clinical evidence. Evidence-based recommendations are set forth for the management of risk factors, including hypertension, dyslipidemia and diabetes, through lifestyle modifications and pharmacological interventions. The purpose of this paper is to review the topic of stroke prevention in light of current guidelines and clinical implementation patterns for primary care physicians, and to discuss new and emerging clinical evidence, with a focus on antiplatelet treatment.     

Toxoplasma gondii: transmission, diagnosis and prevention

Toxoplasmosis, caused by the protozoan parasite Toxoplasma gondii , is one of the most common parasitic infections of man and other warm-blooded animals. It has been found world-wide from Alaska to Australia. Nearly one-third of humanity has been exposed to this parasite. In most adults it does not cause serious illness, but it can cause blindness and mental retardation in congenitally infected children and devastating disease in immunocompromised individuals.     

Rapid immunohistochemistry applied to intraoperative diagnosis: a critical analysis]

A series of 1378 intra-operative frozen diagnoses performed in our department over two years (1998-1999) was studied in order to assess the agreement with the diagnosis on formalin-fixed, paraffin-embedded sections. In selected cases, a rapid immunostaining (IS) method was applied on frozen sections to solve diagnostic problems. Rapid IS allowed us to determine the histotype of poorly differentiated neoplasms, the origin of lung nodules and the presence of nests of neoplastic cells on resection margins. The method delayed the answer by about 20 minutes, and was always previously arranged with the surgeon. Rapid IS method was performed using routine reagents and was not repeated on formalin-fixed, paraffin-embedded sections of the same cases, thus avoiding additional costs.     

Hypocholesterolemias: causes and diagnosis]

Most of the hypocholesterolemias in adults and children are presented and the non-cardiovascular risk of low serum cholesterol (cancer, depressive illness.) is discussed. A good assessment of hypocholesterolemia is provided by usual laboratory lipid tests (total, HDL- and LDL-cholesterol, apolipoproteins B and A1) and completed by lipid assays of parents in case of familial diseases. The diagnosis of secondary hypocholesterolemias is easy in well-known causes (liver diseases, hyperthyroidism, digestive malabsorption) but less obvious in other cases (fever, traumatism, inflammatory disease); nevertheless, it is necessary to avoid expensive laboratory investigations which will be reserved for severe familial hypocholesterolemias (in order to improve the treatment and the knowledge of these rare diseases); however diagnosis fails in some well-tolerated familial cases.     

2,8-dihydroxyadenine nephrolithiasis: from diagnosis to therapy

Adenine phosphoribosyltransferase (APRT, EC 2.4.2.7) deficiency is an enzymopathy of purine metabolism, which is inherited as an autosomal recessive trait. APRT is a salvage enzyme that normally catalyzes the conversion of adenine to adenosine monophosphate. APRT deficiency results in adenine accumulation with oxidation by xanthine dehydrogenase (XDH; EC 1.1.1.204) to 2,8-dihydroxyadenine (2,8-DHA) then excreted in urine. This compound is extremely insoluble and its crystallization can lead to stone formation and renal failure. The diagnosis of the disease is based on stone analysis by infrared spectroscopy or microscopic examination of urine, which may reveal typical 2,8-DHA crystals. The enzyme activity measurements in erythrocyte lysates will identify both homozygotes and heterozygotes for APRT deficiency. Molecular approach can identify mutations which are responsible of this inherited disease. Two types of deficit are commonly distinguished, depending on the level of residual APRT activity: type I, mainly observed in Caucasian subjects, in whom the enzyme activity is undetectable in homozygous patients and type II, found in Japanese patients who are able to form APRT but the enzyme activity is strikingly reduced because a low affinity for phosphoribosylpyrophosphate. The crystallization of 2,8-DHA and subsequent renal damages may be prevented with allopurinol therapy, a xanthine oxidase inhibitor. The role of the laboratory is crucial to detect APRT deficiency and to assess the efficacy of therapy, the objective being to avoid 2,8-DHA crystal formation.     

Ventilator-associated pneumonia: diagnosis, treatment, and prevention

While critically ill patients experience a life-threatening illness, they commonly contract ventilator-associated pneumonia. This nosocomial infection increases morbidity and likely mortality as well as the cost of health care. This article reviews the literature with regard to diagnosis, treatment, and prevention. It provides conclusions that can be implemented in practice as well as an algorithm for the bedside clinician and also focuses on the controversies with regard to diagnostic tools and approaches, treatment plans, and prevention strategies.     

Transfusion related acute lung injury (TRALI): an unrecognised pathology

Transfusion related acute lung injury (TRALI) is a rare but potentially severe complication of blood transfusion, manifested by pulmonary oedema, fever and hypotension. The signs and symptoms are often attributed to other clinical aspects of a patient's condition, and therefore, TRALI may go unrecognised. It has been estimated to be the third cause of transfusion related mortality, so it should be better diagnosed. Cases are related to multiple blood units, such as white blood cells, red blood cells, fresh frozen plasma, platelets or intravenous immunoglobulins. Physiopathology of TRALI is poorly understood, and still controversial. It is often due to an immunological conflict between transfused plasma antibodies and recipients' blood cells. These antibodies are either HLA (class I or II) or granulocyte-specific. They appear to act as mediators, which result in granulocytes aggregation, activation and micro vascular pulmonary injury. Lipids or cytokines in blood units are also involved as TRALI priming agents. Diagnosis is based on antibody screening in blood components and on specific-antigen detection in the recipient. The screening of anti-HLA or anti-granulocytes is recommended as part of prevention for female donors who had been pregnant. Preventative measures should also include leucoreduction and measures to decrease the amount of priming agents in blood components. In this article, we summarise what is known about TRALI, and we focus attention on unanswered questions and controversial issues related to TRALI.