Fiebre mediterránea familiar sin fiebre recurrente / No disponible

Describimos el caso de una paciente con historia de pericarditis recurrentes de 16 años de evolución sin fiebre objetivable ni de patrón recurrente. Se le realizan múltiples estudios tratando de averiguar la etiología de la enfermedad. Finalmente, surge la sospecha de fiebre mediterránea familiar con la confirmación diagnostica de la amplificación genética específica de los exones 2 y 10 del gen MEFV. Destacamos la importancia de la sospecha diagnóstica en casos atípicos (AU)

No disponible

Fab fragments of ovine antibody to colchicine enhance its clearance in the rat.

CONTEXT: Colchicine is an anti-inflammatory alkaloid used for the treatment of acute gout, but has a narrow therapeutic index. Colchicine overdoses are relatively rare, but have high mortality requiring rapid treatment. OBJECTIVE: To evaluate the ability of a newly available ovine fragment antigen-binding (Fab) antibody to colchicine (ColchiFab(™)) to protect rats against renal and other injury 24 h after colchicine ingestion. MATERIALS AND METHODS: Rats were gavaged with colchicine (5 mg/kg), then 2 h later injected intraperitoneally with 5 ml of sterile saline, or Fab anti-colchicine, a newly available ovine antibody to colchicine. Samples of blood were taken at 1, 2, 5 and 24 h after gavage, and urine was collected from 5 to 24 h after gavage. Concentrations of colchicine in tissue, blood and urine were measured by liquid chromatography/mass spectrometry, concentrations of Fab anti-colchicine, urinary neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 or KIM-1 by enzyme-linked immunosorbent assay or ELISA, while concentrations of creatine kinase and creatinine (Cr) were measured enzymatically. RESULTS: Colchicine equilibrated rapidly throughout the body and increased serum creatine kinase. Fab anti-colchicine also rapidly redistributed to the blood and remained at high concentrations over 24 h. Fab anti-colchicine caused a rapid 7.1-fold increase in serum colchicine level, followed by excretion of both colchicine and Fab anti-colchicine through the urine. This was associated with the accumulation of colchicine in the kidney, a reversal of colchicine-induced diarrhoea, and increasing urinary NGAL level; from 168 ± 48 to 477 ± 255 ng/mmol Cr [mean ± standard deviation or SD]. DISCUSSION: Fab anti-colchicine greatly increased the clearance of colchicine, although increasing NGAL level suggested the presence of mild kidney damage. CONCLUSION: These data suggest clinical utility for Fab anti-colchicine in the treatment of colchicine overdose.

Th1 cytokine pattern (IL-12 and IL-18) in bronchoalveolar lavage fluid (BALF) before and after treatment with interferon gamma-1b (IFN-gamma-1b) or colchicine in patients with idiopathic pulmonary fibrosis (IPF/UIP).

BACKGROUND AND AIM: Characterization of the biologic effects of Th1 cytokines will enhance the understanding of idiopathic pulmonary fibrosis (IPF) pathogenesis and treatment selection. Th1 response is characterized by increased expression of IFN-gamma, interleukin (IL)-12 and IL-18. The present study aims to evaluate the role of Th1 cytokines and their possible changes in the bronchoalveolar lavage fluid (BALF), before and after treatment with IFN-gamma-1b or colchicine. PATIENTS AND METHODS: We studied prospectively 10 patients (8 male, 2 female) of median age 67 yr with histologically confirmed IPF/UIP. Patients were randomly assigned to receive either IFN-gamma-1b 200 microg sc (5 patients) or colchicine 1 mg qd (5 patients) plus prednisone 10 mg qd. BALF IL-12 and IL-18 levels were measured before and after treatment. RESULTS: BALF IL-12 levels before and after treatment did not differ significantly between the two treatment groups. However, BALF IL-18 levels were significantly decreased after treatment with IFN-gamma-1b (mean +/- SD, 58.4 +/- 15.6 pg/mL vs 42.8 +/- 4.90 pg/mL, p < 0.05). A significant difference was also found after treatment with colchicine (mean +/- SD, 66.8 +/- 36.9 pg/mL vs 42.6 +/- 1.08 pg/mL, p < 0.01). A significant correlation was found between IL-18 BALF levels and the BALF neutrophils (r = 0.75, p = 0.024). CONCLUSION: Our data suggest the potential role of IL-18 as an inflammatory marker in the pathogenetic pathway of IPF such as its possible downregulation by IFN-gamma-1b treatment. Further studies are needed in a higher number of patients in order to define the precise role of both cytokines during the immunoregulatory response with IFN-gamma-1b.

Enhanced cellular uptake and transport of polyclonal immunoglobulin G and fab after their cationization.

Antibodies are poorly transported across cell membranes and biological barriers in vivo. Cationization of antibody molecules by the derivatization of surface carboxyl groups generating primary amino groups could represent a strategy for intracellular antibody delivery. Before cationization of polyclonal colchicine-specific IgG and Fab, using hexamethylenediamine the isoelectric point (pl) of native IgG and Fab (nIgG and nFab) was in the range of 5.9 9.0 and 8.7-9.3, respectively. The pI of cationized IgG and Fab (cIgG and cFab) were both higher at 8.7, 10.3 and 9.5 -11, respectively. The affinity and specificity of both IgG and Fab were not modified by cationization. When HL 60 cells were incubated with the native or cationized 125I-BSA. -IgG and -Fab, the maximal cellular uptake of clgG and cFab was 3.2 and 2.4 times higher than that of nIgG and nFab at an extracellular concentration of 500 ng/ml. Results also indicated that the uptake was dose- and temperature-dependent suggesting absorptive-mediated endocytosis of cationized antibodies by HL 60 cells. Confocal microscopy analysis indicated that the cationized antibodies were present in the plasma membranes and cytoplasm of HL 60 cells. Finally, a study with bovine arterial endothelial monolayer cells showed that the transport of cIgG and cFab through the monolayer cells was 3.3- and 4.3-fold higher for 125I-cIgG and 125I-cFab than those of the corresponding native forms.

A simple method for determining K(A)s of both low and high affinity IgG antibodies.

A rapid and convenient method for measuring affinity constants (K(A)) of IgG antibody-hapten complexes is described. A key advantage of this method is its suitability for quantification of both low and high affinity interactions. A comparison is made of the K(A)s of the low affinity anti-phosphocholine (PC) antibody T15 (K(A) = 2.9 x 10(5) M(-1)) and five heavy chain complementarity determining region 2 (HCDR2) mutant antibodies expressed as IgG2b transfectants. As a demonstration of the general applicability of the technique, colchicine binding to the high affinity monoclonal IgG2a antibody C44 (K(A) = 1.5 x 10(9) M(-1)) is measured also; thus the assay is applicable over a four-log range of affinities. The assay, based upon use of fixed Staphylococcus aureus Cowan I strain cells as an adsorbent for antibody-radiolabeled antigen complexes, is conducted over a range of hapten concentrations at constant antibody concentration. The K(A) is obtained by Scatchard analysis.

[Follow-up and therapy of acute colchicine poisoning]. / Verlauf und Therapie der akuten Colchicinintoxikation.

Colchicine poisoning is a rare event. Its outcome is, compared to other drug intoxications, often serious or even fatal. Intaxications with colchicine may occur by ingestion of tablets as well as by consumption of meadow saffron leaves (Colchicum autumnale) that are often mistakenly collected instead of the leaves of ramson herb (Allium ursinum). Colchicine poisoning typically shows three phases: initially gastrointestinal symptoms predominate, in the second phase multiorgan failure may occur possibly leading to death. In case the patient survives, the third phase of recovery follows during which the patients often present with hair loss. The fatal dose of acute colchicine poisoning is estimated at about 0.9 mg/kg. Since hemodialysis and hemoperfusion are not effective measures because of the high volume of distribution, an aggressive primary decontamination with gastric lavage and activated charcoal is required as early as possible. A promising new aspect in the treatment of heavy colchicine overdose is the immunotherapy with colchicine-specific fab-fragments. At present this treatment is still in an experimental stage and has been applied so far to one patient with beneficial effects. Unfortunately colchicine-specific antibodies are not yet commercially available.

[Immunotoxicotherapy]. / Immunotoxicothérapie.

Immunotoxicotherapy has been used against animal venoms for almost a century. The last several years have brought major innovations in its safety and efficacy, the processes of fragmentation permitting a greater volume of distribution, diminished risk of sensitization and renal elimination. This progress is clearly illustrated in the case of digitalis and colchicine. Hope exists for tricyclic antidepressants and cocaine. The efficacy of immunotoxicotherapy does not eliminate the necessity of aggressive symptomatic therapy in the course of life-threatening intoxications. Untoward effects appear rare and minor, mainly due to the heterogeneity of active binding sites and to immunogenicity (with risks of hypersensitivity and serum sickness). The elevated cost of immunotoxicotherapy and its restriction to drugs toxic at low doses (on the order of a few mg) limit its application at present.

Efflux of intracellular colchicine in lymphocytes with colchicine-specific Fab fragments.

Uptake of [3H]colchicine (2.5 ng/ml) by human lymphocytes in culture was slow in the length of time to reach steady state (> 48 hr) and was limited in the maximal intracellular colchicine amount (1-2% of total extracellular colchicine). Efflux of intracellular colchicine was investigated 40 hr after colchicine cell exposure by using either washing of the extracellular medium or adding different colchicine-specific Fab fragments:colchicine dose molar ratios of 0.5, 1 and 5. Except for the 0.5 dose molar ratio, the kinetics of [3H]colchicine efflux from lymphocytes induced by extracellular specific Fab fragments were similar to those obtained by washing and were characterized by a first-order decline with half-lives ranging from 15.5 to 16.4 hr. These half-lives were in the same range as those characterizing the dissociation of colchicine from the intracellular tubulin receptor. Our data demonstrate that a tightly bound intracellular toxin may be extracted by antibody with high affinity for the toxin present in the extracellular space at a rate depending on the rate of dissociation of the toxin from its receptor.

Monoclonal digoxin-specific antibodies induce dose- and affinity-dependent plasma digoxin redistribution in rats.

The effect of three monoclonal digoxin-specific antibodies on total and free digoxin plasma disposition was studied in rats in order to determine the role of affinity constant (Ka) and dose. Thirty minutes after digoxin infusion, administration of a stoichiometrical dose of the ICIO, 6C9 and 9F5 IgG (Ka = 6 10(9), 3.1 10(8) and 2.5 10(7) M-1, respectively) resulted in a plasma digoxin increase linearly related to Ka. The mean free plasma digoxin was 0.6 +/- 0.4, 7.8 +/- 3.3 and 43 +/- 22% respectively after 1C10, 6C9, and 9F5 IgG infusion in comparison to 70 +/- 9% in the control group. When the IgG:digoxin ratio increased from 1 to 5, plasma digoxin Cmax and AUCT also increased as a function of both affinity (Ka) and dose (N), but not linearly. The product of NKa defined an immunoreactivity factor that was well fitted to the digoxin redistribution parameters (Cmax and AUCT) by a Hill equation.

Radioimmunoassay of colchicine with antisera exhibiting variable cross-reactivity.

Colchicine-specific antibodies were produced in either goats or rabbits immunized with three different colchicine haptens conjugated to bovine serum albumin (BSA) at different coupling sites on the three rings of colchicine. Antibodies exhibited a variable cross-reactivity for metabolites and structural analogs of colchicine, which were dependent on the site at which colchicine coupled to the protein carrier. Specificity was also checked on urine samples by separating metabolites using high-performance liquid chromatography (HPLC) and radioimmunoassay (RIA) in tandem. The three antisera presented similar high-affinity constants for colchicine of the order of 10(10) M-1. A sensitive RIA for plasma colchicine was developed with each antiserum. The limit of detection of the three RIAs was 0.2 ng/ml. The inter- and intraassay coefficients were < 13%. RIA was linear up to 8 ng/ml. This RIA procedure was used to study the pharmacokinetics of a single dose of 1 mg oral colchicine in healthy volunteers and the colchicine concentrations of 27 plasma samples from patients on long-term colchicine treatment. No significant differences in plasma colchicine concentrations using the three assays were observed. This RIA procedure appears suitable for plasma colchicine pharmacokinetics and monitoring investigations.

Antibody treatment of toxin poisoning--recent advances.

The major responses to the administration of specific antibody or toxin-specific fragment are described. Toxin sequestration depends on the extent and rate of antibody distribution, the antibody affinity and its ability to form a non-active immune complex. Toxin redistribution is mainly influenced by the reversible binding and efflux kinetics of the toxin from the receptor. Finally, toxin elimination adopts the antibody elimination properties for low molecular weight compounds. These three basic mechanisms of the immuno-detoxification process could be optimized by designing the ideal antibody, in terms of size and origin, to inactivate the toxic properties. Calculation of the amount of infused antibody should be derived from the slope of the dose-effect curve rather than stoichiometrically.

Effect of colchicine-specific Fab fragments on the hepatic clearance of colchicine.

The influence of colchicine-specific Fab fragments on hepatic metabolism and biliary excretion of colchicine was studied in the isolated perfused rat liver. Isolated rat livers were perfused for 180 min with either [3H]colchicine (initial concentration: 50 ng/ml) or Fab-[3H] colchicine in a stoichiometrical proportion at a constant flow of 100 ml/min in a recirculating system. Based on perfusate concentrations, the hepatic extraction ratio of colchicine was more than 15-fold decreased when colchicine was bound to Fab fragments (E = 0.011 +/- 0.001) than when it was infused alone (E = 0.16 +/- 0.01) (p < 0.01). The extensive binding of colchicine to Fab over the experimental period as demonstrated by equilibrium dialysis (97 +/- 2%) prevented hepatic uptake. At the end of the colchicine perfusion experiment, 74.2 +/- 4.9% of the radioactivity infused was excreted by the biliary route. In contrast, biliary excretion of radioactivity was 10-fold lower when [3H]colchicine was perfused complexed with Fab fragments (p < 0.01). However, the metabolic profile of colchicine was not affected by Fab fragments. The apparent half-life of colchicine metabolites calculated from biliary data was similar to that of colchicine, indicating that the biliary excretion of these metabolites was formation rate-limited. Inhibition of colchicine uptake by specific Fab fragment was confirmed in vitro with isolated hepatocytes.

Analytical control procedures of immunoreactivity for IgG and Fab fragments specific to haptens.

This study investigates immunoreactivity control procedures, i.e., specificity, affinity constant (Ka), and specific active binding sites (SABS), for polyclonal anticolchicine, monoclonal antidigitoxin IgG and Fab fragments, and antidigoxin Fab fragments (Digidot). Preliminary control procedures for IgG and Fab fragment purity indicated that all reagents were immunologically pure. All IgG and Fab fragments exhibited similar cross-reactivity and Ka. No decrease in percentage of Fab fragment SABS was observed after papain cleavage of anticolchicine and antidigitoxin IgG. Nevertheless, only 4.3 +/- 1.2% of nonimmunopurified anticolchicine polyclonal Fab fragments and 76.2 +/- 2.3 to 88.7 +/- 2.5% of different batches of immunopurified anti-digoxin Fab (Digidot) were active, the latter percentage being in the range of the 85% specified by the manufacturer. Only 58 +/- 3% of digitoxin-specific monoclonal IgG was active and 67 +/- 7% of its Fab fragments. Results show the importance of determining the ratio of SABS to presumed total specific binding sites for pharmaceutical monoclonal and polyclonal antibody preparations against haptens.

Colchicine-specific Fab fragments alter colchicine disposition in rabbits.

High-affinity goat antibodies and Fab fragments (Ka = 1.1 x 10(10) M(-1) specific to colchicine were prepared to study their effect on colchicine pharmacokinetics in rabbits. First, colchicine disposition kinetics were investigated in four control rabbits after administration of 0.1 mg/kg i.v. Total and free plasma and urine colchicine were assayed by specific radioimmunoassay. The mean elimination half-life of total plasma colchicine was 16 +/- 2.9 h. Colchicine has a large volume of distribution (8.8 +/- 1.8 l/kg) and a low systemic clearance (114.6 +/- 3.4 ml.h-1.kg-1). Renal clearance represented 30.7 +/- 1.9% of total body clearance. The free plasma colchicine fraction was 70% after equilibrium dialysis. Second, 1.5 h after injection of 0.1 mg/kg colchicine, four rabbits were infused over 0.25 h with colchicine-specific Fab fragments at a half-stoichiometrically equivalent dose compared to the colchicine dose. Within 15 min after Fab infusion, total colchicine concentrations increased 10- to 16-fold. Mean area under the plasma concentration-time curves increased 20-fold compared to controls. The free plasma fraction decreased to an undetectable level over a period of 2 h. The Fab fragment administration also produced, respectively, a 24- and 17-fold decrease in the volume of distribution and systemic clearance. Colchicine recovered in urine was significantly higher than in the control group: 44.7 +/- 2.3 and 30.9 +/- 2% of the dose, respectively (P less than .05). These data suggest that high-affinity colchicine-specific Fab fragments can sequestrate and extract colchicine from tissues to the vascular compartment with subsequent colchicine excretion by the renal route.

Dose-dependent reversal of acute murine colchicine poisoning by goat colchicine-specific Fab fragments.

The use of colchicine-specific Fab fragments is of interest in human poisoning. In the present study, we show the efficacy of Fab fragments in reversing colchicine toxicity in mice. High affinity antibodies (Ka = 2 x 10(10) M-1) against colchicine were raised in goats; Fab fragments were purified by DEAE chromatography after papain hydrolysis of IgG. Mice were intoxicated with a 100% lethal colchicine dose (3.8 mg/kg). When a half molar dose (M/2) of Fab fragments in relation to the colchicine dose was intravenously and intraperitoneally administered 90 min after colchicine infusion using a multiple dosage schedule, 80% of the Fab-treated mice survived compared to the control group which did not receive Fab fragments (P less than 0.01). Using a M/4 and M/8 dose of Fab fragments, the mortality was respectively 50% and 80%. The dose-effect relationship was linear (r = 0.99). Delayed administration of a M/2 dose of Fab fragments 6 h after colchicine administration resulted in 50% survival (P less than 0.01). Body temperature and body weight were selective markers of the severity of the intoxication. In the control group, a marked decrease of body temperature was observed following the first few hours after the intoxication (-21% compared to basal value 48 h after colchicine). In the Fab-treated group, the decrease was inversely related to the Fab fragment dose. Body temperature returned to the basal values 7 days after intoxication. A progressive decrease in body weight was concomitantly observed in intoxicated mice until death, while values returned to baseline 9 days after colchicine in surviving Fab-treated mice.

Reversal of colchicine-induced mitotic arrest in Chinese hamster cells with a colchicine-specific monoclonal antibody.

The ability of a high-affinity colchicine-binding monoclonal antibody to reverse the effects of colchicine on Chinese hamster ovary cells was investigated. Using flow cytometry, a complete mitotic blockade was demonstrated after 16 hours with 2.5 x 10(-7) mol/l (molar) colchicine. Colchicine-induced changes were reversible when equimolar antibody was added simultaneously with or up to 6 hours after colchicine. With further delay in addition of antibody, a progressive irreversible increase in mitotic blockade and increase in mean cell size was observed. Prolonged colchicine exposure, without antibody reversal, led to polyploidy and structural chromosome breakage. Early antibody reversal restored cells to the diploid state, whereas delayed reversal resulted in a time-dependent increase in polyploidy. Colchicine-induced polyploidy and chromosomal aberrations may be the basis for both colchicine toxicity and the time-dependent increase in irreversibility of colchicine effects.