1/12. Immune hemolytic anemia caused by sensitivity to a metabolite of etodolac, a nonsteroidal anti-inflammatory drug.BACKGROUND: Immune hemolytic anemia can be caused by sensitivity to many different drugs. In some instances, the sensitizing compound can be identified by in vitro testing, but results are often negative. One reason for this is that a drug metabolite formed in vivo can be the sensitizing agent, but the responsible metabolites have rarely been identified at a chemical level. This report describes a patient who developed severe, Coombs-positive hemolytic anemia on two occasions after taking the nonsteroidal anti-inflammatory drug etodolac. Studies were performed to characterize etodolac metabolites to which this patient was sensitive. CASE REPORT: serum was tested for antibody in the presence and absence of drug using conventional methods and urine from individuals taking etodolac as a source of drug metabolites. Urinary metabolites of etodolac were identified by high-pressure liquid chromatography analysis. Glucuronide conjugates of etodolac and the 6-OH metabolite of etodolac were synthesized in a rat liver microsomal system to obtain reference standards. RESULTS: The patient's serum gave only trace ( /-) reactions with normal RBCs in the presence of etodolac but reacted strongly (4 ) in the presence of urine from an individual taking this drug. The active urinary metabolites were identified as etodolac glucuronide and 6-OH etodolac glucuronide. CONCLUSION: This patient appears to have experienced acute, severe immune hemolytic anemia on two occasions because of sensitivity to the glucuronides of etodolac and 6-OH etodolac. In patients suspected of having drug-induced immune hemolytic anemia, RBC-reactive antibodies can sometimes be detected by using urine from an individual taking the implicated medication as the source of drug metabolites in in vitro reactions. For patients who present with acute immune hemolysis, a careful history of drug exposure should be taken, and, where indicated, confirmatory testing should be performed to identify the sensitizing drug and prevent inadvertent reinduction of hemolysis at a later time.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
2/12. Hypoglycaemia due to insulin autoimmune syndrome: report of two cases with characterisation of HLA alleles and insulin autoantibodies.OBJECTIVE: Insulin autoimmune syndrome (IAS) has been reported mainly in japan and so far only 27 IAS cases have been described from outside asia. We describe two unrelated Portuguese patients with IAS and characterise their insulin autoantibodies and HLA alleles. patients: Patient 1, a 24-year-old white female suffered an episode of unconsciousness in the late postprandial state and blood glucose was found to be 33 mg/dl with serum insulin levels of >3980 microIU/ml (normal range 0-30 microIU/ml). She was receiving monthly injections of penicillin g for the prophylaxis of recurrent tonsillitis. Patient 2, was a 19-year-old white female, with episodes of sweating, hand tremor, weakness and hunger occurring in the postprandial state and blood glucose levels during the attacks of 28-56 mg/dl. Very high insulin levels (602-708 microIU/ml) were present. methods AND RESULTS: Anti-insulin antibodies, determined by a semi-quantitative method, were strongly positive in both patients (91.7% in patient 1 and 88.6% in patient 2; normal range < or =7%). Sephadex G-100 chromatography of the sera showed most of insulin immunoreactivity present in the void volume which was retained by an affinity column with anti-human-immunoglobulin g antibodies (87% and 95% from patients 1 and 2 respectively). Scatchard plot analysis and molecular typing of the DRB1 gene revealed a polyclonal antibody and DRB1*0406 in patient 1, and a monoclonal antibody and DRB1*0403 in patient 2. CONCLUSIONS: These two Portuguese patients with IAS had different HLA-DR4 subtypes and insulin autoantibodies: DRB1*0406 and a polyclonal antibody in a patient treated with penicillin, and DRB1*0403 and a monoclonal antibody in a patient with "idiopathic" IAS.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
3/12. Monocytoid B cell lymphoma associated with antibodies to myelin-associated glycoprotein and sulphated glucuronyl paragloboside.Monocytoid B cell lymphoma (MBCL) is an immunologically and morphologically well-defined low-grade lymphoma with a predilection for lymph nodes of the parotid region. We describe an association of MBCL with anti-myelin-associated glycoprotein (MAG) polyneuropathy in a 53-year-old male. The diagnosis of stage IV MBCL with nodular bone marrow infiltration, sjogren's syndrome and sensorimotor polyneuropathy was made in October 1996. serum immunoelectrophoresis demonstrated IgMkappa paraprotein. This was then cross-reacted with epitopes of MAG and sulphated glucuronyl paragloboside (SGPG) on myelin sheaths, and detected by thin layer chromatography and Western blot. Direct immunofluorescence of a sural nerve biopsy showed loss of myelin fibres, segmental demyelinization and IgM deposits on the myelin sheaths. The cerebrospinal fluid was normal. After six cycles of chemotherapy (ChlVPP protocol), all the patient's haematological parameters normalized accompanied by an improvement in neurological signs. The improvement of the polyneuropathy after chemotherapy indicates that the autoimmune anti-MAG and anti-SGPG antibodies resulted from the neoplastic lymphoid proliferation.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
4/12. Antiidiotypic PTH antibodies as a cause of elevated immunoreactive parathyroid hormone in idiopathic hypoparathyroidism, a second case: another manifestation of autoimmune endocrine disease?A 69-year-old man became hypocalcemic under medical observation. The hypocalcemia occurred in the presence of circulating immunoreactive parathyroid hormone (PTH). Common causes of secondary hyperparathyroidism were excluded, as was PTH resistance using PTH infusions. The immunoreactive PTH was examined in detail. PTH immunoreactivity (1) was not retained on a C18 SPE-column, suggesting unusual molecular or physicochemical properties, unlike bona fide PTH; (2) was precipitated with 15% PEG, indicating a molecular size far in excess of native PTH; (3) had an apparent molecular size similar to immunoglobulins on size exclusion chromatography; (4) was retained on affinity chromatography with both Protein A and anti-hIgG antibodies. These data lead us to conclude that the immunoreactive PTH was due to antiidiotypic PTH autoantibodies. No significant quantities of true PTH were found in the patient's serum suggesting that his hypoparathyroidism was a result of PTH deficiency. autoimmunity might explain the occurrence of both processes if an arrested antiidiotypic antibody cascade is assumed.- - - - - - - - - - ranking = 2keywords = chromatography (Clic here for more details about this article) |
5/12. Insulin autoimmune syndrome associated with benign monoclonal gammopathy. Evidence for monoclonal insulin autoantibodies.A 64-yr-old man with benign monoclonal gammopathy developed recurrent episodes of severe hypoglycemia but lacked evidence of insulinoma or exogenous insulin administration. The patient's plasma was found to contain anti-insulin antibodies and large amounts of extractable insulin (1110 microU/ml), which was identified as human insulin by high-performance liquid chromatography (HPLC). The anti-insulin antibodies consisted solely of IgG and lambda-light chains. Scatchard analysis of these antibodies revealed an almost straight-line relationship, with markedly low affinity and high capacity. An immune complex made of 125I-labeled insulin and the patient's antibodies emerged in a molecular-sieve HPLC as almost a single peak, suggesting a homogeneous antibody population. In addition, the patient's M protein was separately shown to be the IgG and lambda-light-chain type. We suggest that the insulin autoantibodies responsible for the spontaneous hypoglycemia in this patient are monoclonal and of M protein origin.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
6/12. Anomalous Raji cell activity related to dna binding in some patients with autoimmune disease.We examined sera from patients with autoimmune disease that showed a discrepancy between the Raji cell assay and other tests for circulating immune complexes where the Raji cell activity was highly elevated. Using gel filtration chromatography, we found that the Raji cell activity was associated with monomeric IgG and little evidence of aggregates in the samples. Samples elevated for circulating immune complexes by all tests showed aggregates with associated Raji cell activity. The activity in discrepant samples was decreased by up to 40% by absorption of the IgG fraction with dna-cellulose prior to the Raji cell assay. It is suggested that binding by autoantibodies to the Raji cell membrane is due to a variety of mechanisms.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
7/12. A treatable multifocal motor neuropathy with antibodies to GM1 ganglioside.We report 2 patients with a treatable, immune-mediated motor polyneuropathy associated with antibodies to defined neural antigens. In these patients asymmetrical weakness developed in one arm and progressed over 2 to 3 years to involve the other arm, legs, and trunk. Both patients were initially diagnosed as having lower motor neuron forms of amyotrophic lateral sclerosis. However, repeated electrophysiological testing eventually showed multifocal conduction blocks in motor but not sensory fibers compatible with patchy selective demyelination. serum testing by thin-layer chromatography and enzyme-linked immunosorbent assay revealed that both patients had high titers of antibody directed against GM1 and other gangliosides. Initial therapeutic trials of prednisone (100 mg daily for 4 to 6 months) and plasmapheresis were unsuccessful. Treatment with cyclophosphamide, however, was followed by marked improvement in strength in both patients.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
8/12. Characterization of circulating insulin in insulin autoimmune syndrome.We examined the forms of circulating insulin in three patients with the insulin autoimmune syndrome by a method combining gel filtration and reverse phase high performance liquid chromatography (RP-HPLC). Insulin bound to circulating antibody was dissociated by molecular sieve chromatography at acid pH. The free insulin peak eluted from a Sephadex G-50 column was subsequently chromatographed on a Bio-Gel P-30 column. In all three patients, insulin coeluted with normal human insulin. However, when the partially purified insulins, obtained by gel filtration, were applied to RP-HPLC, an abnormally migrating insulin was found in two of three patients. The insulins were more hydrophobic than normal human, porcine, or bovine insulin, but were different from each other. A third patient had only a single insulin peak on RP-HPLC which corresponded to normal insulin. In contrast, the insulin from insulin-treated diabetic patients with antibodies to exogenous insulin corresponded to either porcine or bovine and normal human insulin. The antibodies in the circulation of these patients with the autoimmune syndrome were of the immunoglobulin g type and contained kappa and lambda-chains in the same proportions as antibodies in insulin-treated patients. autoantibodies could not be distinguished from those secondary to exogenous insulin treatment on the basis of displacement of binding by human, beef, or pork insulin. These results suggest that in certain patients with the insulin autoimmune syndrome, there may be a molecular abnormality of circulating insulin. Whether this comprises a cause for the syndrome or is a result of posttranslational processing of insulin remains to be determined.- - - - - - - - - - ranking = 2keywords = chromatography (Clic here for more details about this article) |
9/12. Clinical and biochemical aspects of the insulin autoimmune syndrome (IAIS).A 44-year old patient presented with recurrent hypoglycemic attacks after ingestion of carbohydrates. High insulin levels in the range of 350 microU/ml (normal range less than 20 microU/ml) were detected which rose to peak levels of 2,460 microU/ml (normal range less than 300 microU/ml) after oral glucose. The apparently high insulin concentrations were caused by insulin autoantibodies interfering in the radioimmunoassay (RIA) system (and thus with correct insulin quantitation). 125I-insulin added to the patient's serum was not bound to dextran-coated charcoal but was precipitated with antihuman IgG serum. The antibodies bound human, porcine, and bovine insulin with similar affinity. Following Sephadex G-50 gel filtration, the patient's insulin eluted after the void volume. Free insulin was extracted from serum using Sep-Pak C 18 cartridges and characterized by high pressure liquid chromatography (HPLC); it eluted similarly to synthetic human insulin. Quantitation of free insulin during a hypoglycemic attack (3.5 h after oral glucose, with a blood sugar of 20 mg/dl) showed an increased insulin level of 50 microU/ml. Insulin receptor concentration on erythrocytes was near the lower normal limit. We believe that the insulin antibodies present in this patient's serum (who supposedly never received insulin) led to the formation of a large circulating insulin pool, binding the insulin released after glucose stimulation, and causing hypoglycemias by delayed postprandial liberation of bound insulin.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
10/12. High performance liquid chromatography used to distinguish the autoimmune hypoglycemia syndrome from factitious hypoglycemia.Recurrent episodes of spontaneous hypoglycemia developed in a 30-yr-old woman who had received a brief course of insulin therapy 10 yr previously. She denied surreptitious insulin administration, and the autoimmune hypoglycemia syndrome was considered. Her insulin levels could not be reliably measured because of the presence of circulating antiinsulin antibodies, which interfere with standard RIA techniques. Reverse phase high performance liquid chromatographic analysis of serum obtained during a hypoglycemic episode revealed a mixture of beef and pork insulins but no human insulin, firmly establishing the diagnosis of factitious hypoglycemia. This case illustrates the value of reverse phase high performance liquid chromatography in characterizing patients in whom the autoimmune hypoglycemia syndrome is suspected.- - - - - - - - - - ranking = 5keywords = chromatography (Clic here for more details about this article) |
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