Israel Medical Association Journal

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. 

Background: Serology of amebiasis is affected by low sensitivity and specificity.

Objectives: To evaluate the advantage of the indirect hemagglutination assay and enzyme-linked immunosorbent assay in the diagnosis of amebiasis, using Entamoeba histolytica soluble antigen (macerated amebic antigens) prepared from four different virulent isolates, continuously cultivated in the presence of the original enteric bacteria.

Methods: Using IHA[1] and ELISA[2] with MAA[3] antigen we examined 147 sera samples from patients with gastrointestinal symptoms, and 11 sera from amebiasis cases (confirmed by microscopy and copro-antigen ELISA ).

Results: Of 104 of the 147 (70.7%) symptomatic cases that were amebiasis positive by IHA, 81 (55.1%) were positive by MAA-ELISA. In addition, of 11 amebiasis cases confirmed by microscopy and copro-antigen ELISA , 7 (64%) were amebiasis positive by both tests. Four species of bacteria were isolated from the ameba cultures: Escherichia coli, Morganella morganii, Proteus mirabilis, and Streptococcus lactis. Elimination of the bacteria from the cultures by an antibiotics cocktail containing gentamicin, imipenem, piperacillin-tazobactam and vancomycin was the preferred method. Absorption of patients' sera to bacterial antigen prior to serological analysis had only a marginal effect.

Conclusions: These results indicate a correlation of 61% between the ELISA developed in this study and the IHA tests in the diagnosis of amebiasis.