Israel Medical Association Journal

Background: Anti-ribosomal-P antibodies have been associated with central nervous manifestations of systemic lupus erythematosus. However, inconsistencies in their prevalence and clinical correlations have become an obstacle to their use as a diagnostic marker of the disease. This lack of consistency might stem from several factors, such as the lag period between clinical manifestations and the time blood was drawn, or the different methods used for antibodies detection.

Objectives: To evaluate three different enzyme-linked immunosorbent assay tests for the detection of anti-Rib-P Abs[1] in patients with SLE[2] and normal controls.

Methods: Sera from 50 SLE outpatients and 50 healthy subjects were tested with three ELISA[3] kits: Kit-1, which uses synthetic peptide comprising the 22 C-terminal amino-acids; Kit-2, which uses native human ribosomal proteins (P0, P1, P2); and Kit-3, which is coated with affinity-purified human ribosomal proteins. ELISA studies were performed according to the manufacturers' instructions.

Results: The prevalence of anti-Rib-P Abs in SLE patients and controls was 30% vs. 0%, 17% vs. 21%, and 30% vs. 14% in kits 1-3 respectively. Anti-Rib-P Abs detected by Kit-1 correlated with the SLEDAI score (SLE Disease Activity Index). No correlation between prior CNS[4] manifestations and anti-Rib-P Abs was observed.

Conclusions: A significant difference was documented between the ELISA kits used for the detection of anti-Rib-P Abs. A correlation was found between these antibodies (evaluated by Kit-1) and concurrent SLEDAI scores, in contrast to the lack of correlation with previous CNS manifestations. This supports the notion of "active serology" that is evaluated at the same time manifestations are present, as well as the need for standardization of laboratory assays in the future that enable a better assessment of anti-Rib-P Abs presence and clinical correlation. 

Background Drug-specific CD8+ TH1 lymphocytes have been found in the peripheral blood and involved skin of patients with drug-induced bullous exanthems.

Objectives To determine whether the interferon-gamma release test can identify culprit drugs in pemphigus patients.

Methods Clinical and laboratory workup for pemphigus was performed in 14 pemphigus vulgaris patients who had been exposed to drugs, and the IFNl[1] release test was conducted on their lymphocytes from heparinized venous blood cultured with medium, phytohemagglutinin and one of 32 drugs, or medium and phytohemagglutinin alone.

Results Ten of the patients and 13 of the 32 drugs exhibited a positive response to the test. Eight of the 10 patients with positive IFNl test results had a less severe course of the disease, with fast reduction in steroid dosage.

Conclusions The findings demonstrate both the ability of the IFNl release test to identify drugs that can induce pemphigus, and its usefulness in the diagnostic workup of pemphigus patients.

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.

Background: Celiac disease is common in both children and adults. Small intestinal biopsy is mandatory for establishing a diagnosis. Anti-endomysial antibodies, detected by immunofluorescence, have a sensitivity and specificity close to 100% in the diagnosis of CD[1]. Recently, tissue transglutaminase has been identified as the target autoantigen of antibodies against endomysium, and TTG[2] antibodies are comparable to EMA-IMF[3] in the diagnosis of CD.

Objective: To evaluate a new enzyme-linked immunosorbent assay kit for EMA, compared to EMA-IMF and TTG antibodies in the diagnosis of CD.

Methods: Our study population included all subjects with positive EMA-IMF who underwent intestinal biopsy (n=21). From the same sera, TTG antibodies and EMA-ELISA[4] were determined, and all antibody results were compared to the biopsy findings.

Results: EMA-IMF was able to predict biopsy findings of CD in 19 of 21 cases (90.5%). When patients with biopsy findings compatible with CD and positive EMA-IMF (n=19) were tested for EMA-ELISA and TTG antibodies, 18 of the 19 were positive for both EMA-ELISA and TTG antibodies. A significant correlation was found between EMA-ELISA and TTG antibody titers (r = 0.74, P < 0.001).

Conclusions: Our study demonstrates that EMA-ELISA is comparable to TTG antibodies in the diagnosis of CD, and supports the use of EMA-ELISA as a serologic marker for this disease.