Accidental potassium dichromate poisoning. Toxicokinetics of chromium by ICP-MS-CRC in biological fluids and in hair.

Intoxications by chromium (Cr) compounds are very life threatening and often lethal. After oral ingestion of 2 or 3g of hexavalent Cr (Cr(VI)), gastrointestinal injury, but also hepatic and renal failure, often occurs which each leads to a fatal outcome in most patients. Cellular toxicity is associated with mitochondrial and lysosomal injury by biologically Cr(VI) reactive intermediates and reactive oxygen species. After Cr(VI) has been absorbed, there is not much that can be done except to control the main complications as the treatment is only symptomatic. The biotransformation of Cr(VI) to Cr(III) reduces the toxicity because the trivalent form does not cross cellular membranes as rapidly. In fact, more than 80% of Cr(VI) is cleared in urine as Cr(III). We report the case of a 58-year-old male patient who was admitted to hospital after accidental oral ingestion of a 30 g/L potassium dichromate (the estimated amount of ingested Cr is about 3g). ICP-MS equipped with a collision/reaction cell (CRC) and validated methods were used to monitor plasma (P), red blood cells (RBCs), urine (U) and hair chromium. For urine the results were expressed per gram of creatinine. After 7 days in the intensive care unit, the patient was discharged without renal or liver failure. P, RBC and U were monitored during 49 days. During this period Cr decreased respectively from 2088 µg/L to 5 µg/L, 631 µg/L to 129 µg/L and 3512 µg/g to 10 µg/g. The half-life was much shorter in P than in RBC as the poison was more quickly cleared from the P than from the RBC, suggesting a cellular trapping of the metal. Hair was collected 2 months after the intoxication. We report a very rare case of survival after accidental Cr poisoning which has an extremely poor prognosis and usually leads to rapid death. For the first time, this toxicokinetic study highlights a sequestration of chromium in the RBC and probably in all the cells.

[A monoclonal immunoglobulin M not visible on the profile of serum capillary electrophoresis]. / Une immunoglobuline M monoclonale invisible sur le profil d'électrophorèse capillaire.

We report a case of an invisible monoclonal IgM on the profile of the serum electrophoresis carried out by the Paragon CZE 2000 system. This case is about a 84 years old man followed for a Waldenström disease. The level of the monoclonal IgM given at the time of the preceding visit one year before was 10 g/L. The electrophoresis is reproduced in two other laboratories using respectively the Hydrasys and Capillarys techniques which have both shown the presence of the monoclonal peak. At this occasion the frequency of these anomalies of migration and the recommendations to avoid the erroneous interpretation of the electrophoresis are discussed. The vigilance and the competence of the biologist are essential to avoid this rare pitfall, induced by the new principle of the capillary electrophoresis.

[Improved reliability of critical data exchange between the biological laboratory and clinical centres. Type of data to transfer and identification of the most relevant tools]. / Fiabiliser les échanges d'informations précieuses entre le laboratoire et les services de soins. Types d'informations à échanger et choix des outils les plus fiables.

The reliability of the transfer of critical data between the biological laboratory and the clinical centres has to be reassessed. We have a legal constraint (GBEA and best practices) to make sure that the appropriate alert is issued for severe and urgent cases. In this paper, we present a study of the performances of data transfer tools, such as the comparison between regular phone and up to date available means like in line printers and network terminals. This paper focuses on the twenty-four hours duty in the hospital at the same level of reliability for alerts.

Prognostic significance of TNF alpha and its p55 soluble receptor in malignant lymphomas.

In 93 newly diagnosed lymphoma patients, tumor necrosis factor alpha (TNF alpha) and its p55 soluble receptor (p55-sR), were prospectively determined in plasma by IRMA and ELISA methods respectively. These 93 patients included 31 patients with low grade lymphoma, 55 with intermediate or high grade lymphoma and 7 with Hodgkin's disease. Median TNF alpha plasma values were 20 pg/mL (range 5-380 pg/mL) in patients versus 7 pg/mL (range 4-9 pg/mL) in healthy control subjects. Presence of TNF alpha level equal or greater than 20 pg/mL was significantly associated with elevated LDH level, serum beta 2-microglobulin level > or = 3 mg/L, hemoglobin < or = 12 g/dL, Ann Arbor stage III or IV disease, and with bulky tumor. High level of TNF alpha was also associated, although less strongly, with B symptoms, poor performance status, and serum albumin < or = 35 g/L, yet it was not associated with change in acute phase protein levels. Levels of p55-sR were also markedly elevated in these lymphoma patients (median of 3.5 ng/mL, range 0.8-18.8 ng/mL) versus 1.45 ng/mL in control subjects (range 1.1-2.3 ng/mL). Level of p55-sR equal or greater than 3.5 ng/mL was significantly associated with poor performance status, B symptoms, beta 2-microglobulin levels > or = 3 mg/L, serum albumin < or = 35 g/L, C-reactive protein > 6 mg/L, hemoglobin < or = 12 g/dL, and bulky tumor. In the whole group of 93 patients, both high TNF alpha and p55-sR levels strongly predicted short freedom from progression and overall survival. This study suggests that elevated TNF alpha and p55-sR plasma levels have a high correlation with other adverse prognostic factors in lymphoma patients and predict their poor outcome.

[Improvements from the reference material CRM 470 in the standardization of the determination of serum proteins]. / Améliorations apportées par le matériau de référence CRM 470 dans la standardisation du dosage des protéines sériques.

The introduction of the CRM 470 in 1993 (certified reference material for 14 serum proteins) and its utilization by industrial companies for cross-calibrating their commercial standards has been an important break-through in protein standardization. This improvement has been clearly illustrated by the last national quality control survey performed in France in may 1995. At this time, about 60% of the 1,870 participants have already adopted the new standardization. The between-run precision (interlaboratory and intertechnique) has been considerably improved by the use of the new international standard (5.8 to 12.2% versus 10 to 24.1% before standardization); the same is true for accuracy. These results should convince the last reluctant laboratories to adopt the new standardization. Thus, it seems now possible to define reference ranges for serum proteins: this is the new task assigned to the Committee for Plasma Protein Standardization of the IFCC.

Elevated circulating levels of TNFalpha and its p55 soluble receptor are associated with an adverse prognosis in lymphoma patients.

In 88 newly diagnosed lymphoma patients, tumour necrosis factor alpha (TNFalpha) and soluble TNF type I receptor (p55-R-TNF) were prospectively determined in plasma by immunoradiometric assay (IRMA) and ELISA methods respectively. These 88 patients included 19 with centrocyto-centroblastic lymphoma, 13 patients with other low-grade lymphoma, and 56 with high-grade lymphoma. Median TNFalpha plasma values were 20 pg/ml (range 5-380 pg/ml) in patients versus 7 pg/ml (range 4-9 pg/ml) in 20 healthy control subjects. Presence of TNFalpha level > or = 20 pg/ml was significantly associated with elevated LDH level (P<0.0001), serum beta2-microglobulin level > or = 3 mg/l (P<0.0001), haemoglobin < or = 12 g/dl (P=0.0001), Ann Arbor stage III or IV disease (P<0.005), and with bulky tumour (P=0.01). High level of TNFalpha was also associated with B symptoms (P<0.005), poor performance status (P<0.05), and serum albumin < or = 35 g/l (P<0.05). Levels of p55-R-TNF were also markedly elevated in these lymphoma patients (median of 3.5 ng/ml, range 0.8-18.8 ng/ml) versus 1.45 ng/ml in control subjects (range 1.1-2.3 ng/ml). Level of p55-R-TNF > or = 3.5 ng/ml was significantly associated with poor performance status (P<0.0001), B symptoms (P<0.0001), beta2-microglobulin levels > or = 3 mg/l (P<0.0001), serum albumin < or = 35 g/l (P=0.0001), C-reactive protein > 6 mg/l (P=0.0003), elevated (>20 pg/ml) IL-6 level (P<0.005), haemoglobin < or = 12 g/dl (P<0.005), and bulky tumour (P<0.001). In the whole group of 88 patients, both high TNFalpha and p55-R-TNF levels strongly predicted short progression-free survival (P<0.005 for both variables) and overall survival (P<0.001 and P<0.001 respectively). In multivariate analyses the elevation of p55-R-TNF retained a higher significance over the other variables and therefore improved the predictive value of the International Prognostic Index. This study suggests that elevated TNF gamma and p55-R-TNF levels have high correlation with other adverse prognostic factors in lymphoma patients and may predict a poor outcome.

Evaluation of the fully automated Cobas Core enzyme immunoassay for the quantitation of antibodies against hepatitis B virus surface antigen.

The Roche Cobas Core automated enzyme immunoassay of antibodies against hepatitis B virus surface antigen (anti-HBs) was evaluated using a protocol complying with the Société Française de Biologie Clinique guidelines. Results showed good precision (CV below 6 and 9% for intra- and inter-assay precision) and accuracy (according to the Paul-Ehrlich-Institute standard); the detection limit of the test was 2 IU/l. The manufacturer's specifications were confirmed and a satisfactory correlation (r = 0.901) was found with an automated method (IMx, Abbott) used for comparison.

[Methods for studying cytokines in biological media]. / Les méthodes d'exploration des cytokines dans les milieux biologiques.

Accurate and sensitive methods for the measurement of cytokines in biological fluids are an absolute prerequisite for a proper use of these mediators in clinical practice. The authors describe the numerous molecular forms under which cytokines can possibly circulate. The potential influence of inhibitors (autoantibodies, soluble receptors) on cytokine assays is discussed. Blood collection for cytokines needs a particular attention to prevent a possible contamination by endotoxins which can trigger cytokines cellular production after sampling. If bioassays historically preceded immunoassays, these last techniques are now very popular, but there is an urgent need for standardisation between the different kits commercially available. In addition, in situ detection of cytokines using molecular biology is an helpful complementary technique to the measurement of circulating cytokines.

Production of proinflammatory cytokines and cytokines involved in the TH1/TH2 balance is modulated by pentoxifylline.

The modulation of cytokine release induced by pentoxifylline (PTX) has recently been demonstrated not to be restricted solely to tumor necrosis factor (TNF)-alpha. This prompted us to study the influence of PTX on a larger spectrum of cytokines with proinflammatory actions [TNF-alpha, interleukin-6, (IL)-6, IL-1 beta, IL-8] or with implied actions in the TH1 (IL-2, IFN-gamma)/TH2 (IL-10) balance. The IL-1RA was also explored. This work was performed using a whole-blood model in which cytokine production is measured after stimulation by lipopolysaccharide (LPS) (25 micrograms/ml) and phytohemagglutinin (PHA) (5 micrograms/ml) in 1:10 diluted whole blood. The stimulation test was performed in blood from healthy controls and from septic patients (without septic shock) in the presence or absence of PTX at 10(-6), 10(-5), 10(-4), or 10(-3) M. In controls and septic patients, at a 10(-4) M PTX concentration the production of IL-2 is strongly diminished (26-32% of the basal level), followed by diminution of IFN-gamma (30-40%). As expected, of the proinflammatory cytokines TNF was the most strongly suppressed (50% of baseline) followed by IL-1 (about 80% of basal production). Finally, IL-10 was also influenced by PTX (65% of baseline). At 10(-4) M, IL-1RA and IL-6 were unaffected by PTX. Taken altogether, our data demonstrate that PTX possesses a much broader spectrum of activity on cytokine production than was initially described, and it appears to be a potential and promising immunotherapeutic agent.

Analytical performances of commercial ELISA-kits for IL-2, IL-6 and TNF-alpha. A WHO study.

The determination of cytokine levels in biological fluids by accurate and sensitive methods is an absolute need to be able to define the involvement of these mediators in various clinical situations. To test if this goal was achieved with ELISA kits, a comparative study was undertaken using various commercial kits (6 for IL-2, 8 for IL-6 and 9 for TNF-alpha). The major aims of the work were to critically analyze the analytical performances of the kits and to illustrate some of the pitfalls the users may face. Substantial differences were noted in terms of sensitivity and behaviour of commercial standards versus international reference preparations. These results clearly illustrate the urgent need for a real standardization of immunoassays for cytokine quantitation.

Study of pentoxifylline induced modulation of TNF alpha and interleukin-6 secretion in healthy and septic patients by the use of an ex-vivo model on whole blood.

The aim of this work is to reinvestigate the pentoxifylline (PTX) action on TNF alpha and IL-6 production using a whole blood ex-vivo model. 5 healthy controls, 2 septic patients (4 samples) and 3 patients in septic shock (7 samples) have been studied. Our data confirm the inhibitory action of PTX on TNF alpha production in healthy controls. This inhibition is nearly complete for a PTX concentration of 10(-3) M. More surprisingly a suppressive activity of PTX on IL-6 secretion has been found both in controls and septic patients. On the 7 samples of the 3 patients with septic shock no TNF alpha production has been detected. Taken altogether, these observations suggest a potential role for PTX as a modulator of the major cytokines involved in the pathogenesis of septic shock.