Israel Medical Association Journal

Objective: To study the mechanism of platelet function inhibition in a patient with acquired thrombasthenia.

Methods: Aggregation assays of platelets from the patient and healthy controls were performed. In addition, anti-glycoprotein (GP) IIbIIIa antibodies binding to normal platelets in the presence or absence of the patient’s serum was studied by flow cytometry.

Results: Aggregation of normal platelets in the presence of patient's plasma was inhibited four- and 2.5-fold in the presence of ADP and arachidonic acid respectively, while collagen-induced aggregation was completely abolished. Ristocetin-induced aggregation was normal. The patient's serum inhibited binding of commercial anti-glycoprotein IIbIIIa antibodies to normal platelets twofold by flow cytometry. Treatment with anti-CD20 monoclonal antibody (rituximab) normalized the patient's platelet aggregation.

Conclusions: These results suggest that the patient developed inhibitory anti-GPIIbIIIa autoantibodies that caused acquired thrombasthenia. 

Objectives: To determine the properties of HAM as an antigenic substrate for the detection of autoantibodies in pemphigus vulgaris and bullous pemphigoid.

Methods: Immunomapping and tandem liquid chromatography mass spectrometry were used to delineate the antigenic structure of HAM in 25 pemphigus patients, 41 pemphigoid patients, and 36 controls. Immunoblotting and indirect immunofluorescence were used to study the diagnostic utility of HAM, and the results were compared to those of indirect immunofluorescence on monkey esophagus, immunoblotting using normal human skin, and enzyme-linked immunosorbent assay (ELISA).

Results: Immunomapping demonstrated the presence of all the antigens known to be targeted in autoimmune bullous skin diseases, in both normal human skin and HAM, except for the absence of BP230, and low threshold levels of Dsg1, Dsg3 and Dsc3 in HAM. HAM indirect immunofluorescence demonstrated anti-basement membrane zone antibodies in 48.7% of the pemphigoid patients, and anti-intercellular space antibodies in 72.0% of the pemphigus patients. HAM immunoblotting did not demonstrate anti-BP230 antibodies, but detected anti-BP180 antibodies in 53.6% of the pemphigoid patients. It did not demonstrate anti-Dsg1 and/or anti-Dsg3 antibodies in any of the pemphigus patients. These results were inferior to those of ELISA and monkey esophagus indirect immunofluorescence.

Conclusions: Compared to other studied methods, HAM does not offer advantages in detecting autoantibodies in bullous pemphigoid and pemphigus vulgaris. 

Background: Anti-red blood cell antibodies, free light chains (FLC) and prothrombotic proteins (PTP) may co-elute with intact immunogIobulin (IgG), and may be the cause of adverse reactions to intravenous immunoglobulin preparations (IVIG).

Objectives: To investigate the presence of residual amounts of these components in IVIG and their effects on ABO blood group agglutination.

Methods: Iso-agglutinin anti-A and anti-B activity was determined with a direct hemagglutination assay of red blood cell (RBC) suspensions from 1% of 46 blood donors together with the serial dilutions of five IVIG (IV1, IV2, IV3, IV4, IV5). Anti-A1 monoclonal antibody was used to confirm reactivity with the A1-reference RBC. The selected IVIG were diluted to a final concentration of 25 mg/ml in 0.15 M NaCl and 0.01 M phosphate-buffered saline (PBS), pH 7.4, with or without a further twofold dilution in a low ionic strength solution.

Results: A variation up to fivefold in the titer strength of anti-A/B activity was observed between the IVIG preparations. A2-type RBC required higher IVIG inputs when tested in 0.15 M NaCl. The differences in FLC kappa and lambda concentrations were as high as > 400 mg/L among the various IVIG. Only IV1 had a significantly high level of antiphospholipid IgG antibodies (18 U/ml). We demonstrated the presence of anti-RBC antibodies, FLC and PTP in IVIG preparations.

Conclusions: Our findings provide clear evidence that IVIG may harbor pathophysiological substrates with a potential risk for adverse effects such as iatrogenic hemolysis, FLC-associated disorders, and thromboembolism. 

Heart failure (HF) accompanied by renal failure, termed cardiorenal syndrome (CRS), encompasses both the development and worsening of renal insufficiency secondary to HF as well as the harmful effects of impaired renal function on the cardiovascular system, and remains a universal clinical challenge. CRS was recently classified into subtypes depending on the etiologic and chronologic interactions between cardiac and renal dysfunctions. The mechanisms underlying the CRS are multifactorial, including hemodynamic alterations, neurohormonal effects, and inflammatory components. However, despite enhanced understanding and awareness of CRS, further elucidation of the mechanisms involved and the appropriate treatment approaches are clearly warranted. CRS is a difficult condition to manage, as treatment to relieve congestive symptoms of HF is limited by a further decline in renal functions, itself a major independent predictor of long-term cardiac morbidity. In order to perform a proper clinical investigation and implement appropriate treatment that will minimize subsequent progression of heart and kidney injury, a comprehensive approach to these two pathologies is crucial. In the present review we discuss current theories behind the mechanistic evolution of the CRS as well as therapeutic issues regarding this multifaceted condition.
 

Background: Anti-lipoprotein lipase antibodies have been described in rare cases of patients with hypertriglyceridemia. However, no systematic study evaluating these antibodies in patients with this lipid abnormality has been undertaken.

Objectives: To analyze the correlation of anti-lipoprotein lipase (anti-LPL) antibodies with other laboratory findings in patients with hypertriglyceridemia but no autoimmune disease.

Methods: We evaluated 44 hypertriglyceridemic patients without autoimmune disease. Clinical and laboratory evaluations included analyses of co-morbidities, fasting lipid profile and anti-LPL antibodies.

Results: Mean patient age was 55 ± 10 years; 46% of the patients were female and 64% were Caucasian. The mean disease duration was 94.4 months and mean body mass index 28.7 ± 3.6 kg/m²; 34.0% were diabetic, 25.0% were obese, 72.7% had systemic arterial hypertension, 75% were sedentary, 15.9% were smokers, 56.8% had a family history of dyslipidemia, 45.5% had a family history of coronary insufficiency, 20.5% had acute myocardial infarction, 9.0% had undergone revascularization and 11.0% angioplasty, 79.5% were being treated with statins and 43.2% were taking fibrates. Median triglyceride levels were 254 mg/dl (range 100-3781 mg/dl), and total cholesterol level was 233 ± 111 mg/dl. High-density lipoprotein was 42.6 ± 15.4 mg/dl, low-density lipoprotein 110.7 ± 42.4 mg/dl and very low-density lipoprotein 48 ± 15 mg/dl. Anti-LPL antibodies were identified in 2 patients (4.5%), both of whom had a family history of dyslipidemia, coronary insufficiency and acute myocardial infarction; one had undergone myocardial revascularization and percutaneous transluminal coronary angioplasty, and both were using fibrates and had normal triglyceride levels.

Conclusions: Our findings demonstrate a correlation between the immune response and dyslipoproteinemia in hypertriglyceridemic patients, suggesting that autoimmune disease contributes to the dyslipidemia process.
 

Background: Several murine models are susceptible to atherosclerosis, such as low density-lipoprotein receptor-deficient (LDLR^-/-) and apolipoprotein E-deficient (apoE^-/-) mice, and are used for studying pathophysiological mechanisms. Atherosclerotic lesions in the aortic valve and thoracic/abdominal aorta are commonly associated with hyperlipidemia. We recently demonstrated the development of large atherosclerotic plaques in Helicobacter pylori-infected heterozygous LDLR^+/- apoE^+/- mice.

Objectives: To measure novel biomarkers related to atherosclerosis, blood coagulation, and oxidative stress in order to investigate their possible pathogenic roles in atherosclerosis-prone mice.

Methods: Mice were fed with a normal chow diet or high-fat diet and sacrificed at different age intervals to measure aortic plaque size. Plasma cholesterol was enzymatically measured. Enzyme-linked immunosorbent assay was used to measure oxidized LDL (oxLDL)/beta-2-glycoprotein I (β2GPI) complexes, immunoglobulin M (IgM) antibodies against native LDL, oxLDL, or oxLDL/β2GPI, and urine 11-dehydro-thromboxane B₂ (11-dhTxB₂) or 8-hydroxy-deoxyguanosine.

Results: There was a parallel increase in plaque size, plasma cholesterol, and urinary 11-dhTxB₂ in atherosclerosis-prone mice. In contrast to atherosclerosis-prone strains, an elevation of urinary 11-dhTxB₂ with no significant plaque generation was observed in LDLR^+/- apoE^+/- mice. The atherogenic autoantigen oxLDL/β2GPI complex was detected only in LDLR^-/- mice. These levels seem to depend on plaque size. IgM antibodies against oxLDL in apoE^-/- mice were found, accompanied by atherosclerotic progression.

Conclusions: Progression of atherosclerotic lesions was associated not only with cholesterolemia but also with platelet activation and natural autoimmune-mediated regulatory mechanism(s) in murine models.