Israel Medical Association Journal

Primary biliary cirrhosis is considered a model autoimmune disease because of the similarities between patients, their relative homogeneous presentation and natural history, and the presence of the signature autoantibody, the anti-mitochondrial antibodies. PBC[1] also illustrates the potential role of genetic and environmental influence and is unique in having several well-defined animal models that recapitulate distinct features of the disease. The pathogenesis of the disease includes genetic predisposition, the production of both innate and adaptive immune responses, and cholangiocyte-specific biology that addresses the specificity of disease. In this review we highlight these features of PBC in comparison to other autoimmune diseases.

Background: Clinical and epidemiologic features of coronary heart disease may not be explained solely by established risk factors. The role of infectious pathogens in the development and rupture of atherosclerotic plaques remains elusive but an association between Chlamydia pneumoniae, Mycoplasma pneumoniae and CHD[1] has been previously reported

Objectives: To determine whether there is an association between mycoplasmal infections and CHD.

Methods: We conducted a prospective cohort analysis of 150 consecutive hospitalized patients with CHD (85 with acute coronary syndrome and 65 admitted for unrelated reasons) and 98 healthy blood donors. Antibody titers for Mycoplasma pneumoniae, M. fermentans, M. hominis and Ureaplasma urealyticum were measured with the agglutination test or specific enzyme-linked immunosorbent assay in all three groups of patients.

Results: Analysis of the antibody titers did not reveal any significant difference in the presence of mycoplasmal antibodies between the patients with ACS[2], patients with known stable CHD hospitalized for non-CHD reasons, and healthy blood donors.

Conclusions: Determination of specific antibodies did not reveal a significant association among different types of mycoplasmal infection and CHD.





[1] CHD = coronary heart disease

[2] ACS = acute coronary syndrome

Background: HER2 is an important prognostic and predictive marker in invasive breast cancer. It is currently assessed by immunohistochemistry for protein over-expression and by fluorescence in situ hybridization for gene amplification. The immunohistochemistry-equivocal cases (2+) are currently retested by FISH[1] to determine eligibility for trastuzumab treatment. Retesting by FISH significantly raises the cost of patient management and sometimes delays treatment. The 4B5 is a new, FDA-approved, rabbit monoclonal antibody for HER2 testing.

Objectives: To examine the reliability of 4B5 IHC[2] HER2 testing in cases found to be HER2 status equivocal by CB11 IHC.

Methods: Twenty-eight invasive breast cancer cases, with an equivocal HER2 status by CB11 IHC, were retested by the 4B5 antibody as well as by FISH analysis. The scoring was performed using the same guidelines as HercepTest and was correlated with the FISH ratio. Results: Of the original 28 CB11 clone designated equivocal cases, 14 (50%) showed negative HER2 staining using the 4B5 clone (HercepTest score 0 and 1+). Five cases (18%) proved to be positive (HercepTest score 3+) and 9 cases (32%) remained equivocal (HercepTest score 2+). The corresponding FISH ratio results showed that all 4B5 negative cases were negative by FISH testing, with a negative predictive value of 100% 4 of 5 of the 4B5-positive cases were positive by FISH testing, with a positive predictive value of 80%. One 4B5-positive case was borderline-high (2.2 ratio) by FISH. The correlation between 4B5 IHC and FISH was statistically significant (P = 0.0013) by chi-square test.

Conclusions: Sequential testing by 4B5 IHC could greatly reduce the need for FISH testing in cases considered HER2 equivocal by CB11 IHC.
 

 
[1] FISH = fluorescence in situ hybridization

[2] IHC = immunohistochemistry

Background: Autoimmune neutropenia of infancy is caused by neutrophil-specific autoantibodies. Primary AIN[1] is characterized by neutrophil count < 500 ml and a benign self-limiting course. Detecting specific antibodies against the polymorphic human neutrophil antigen usually confirms the diagnosis. Current available tests, however, are expensive and inapplicable in many laboratories as they require the use of isolated and fixed granulocytes obtained from donors pretyped for their distinct HNA[2] alloform.

Objectives: To assess the performance of a modified test to identify by FACS-analysis granulocyte-specific antibodies in the sera of neutropenic children.

Methods: We evaluated 120 children with a clinical suspicion of AIN, whose sera were analyzed by flow cytometry for the presence of autoantibodies using the indirect granulocyte immunofluorescence test. In contrast to the traditional tests, the sera were tested against randomly selected untyped neutrophils derived from a batch of 10 anonymous healthy subjects, presumably including the common HNA alloforms. Control sera samples were from patients with chemotherapy-induced, familial or congenital neutropenias. To further assure the quality of the new test, we retested six samples previously tested by the gold standard method. All medical files were screened and clinical outcomes were recorded.

Results: Our method showed specificity of 85%, sensitivity of 62.5%, and a positive predictive value of 91.8%, values quite similar to those obtained by more traditional methods.

Conclusions: The new method showed high specificity for detection of anti-neutrophil antibodies in the appropriate clinical setting and could be an effective aiding tool for clinical decision making.

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. 

Treatment of vasculitides has progressed markedly over the past few decades. Recent therapeutic strategies in severe and refractory anti-neutrophil cytoplasmic antibodies-associated vasculitides include immunomodulating methods (e.g., plasma exchanges), products (such as intravenous immunoglobulins) and, more recently, new agents called biotherapies. Some of them (e.g., anti-tumor necrosis factor-alpha and anti-CD20 monoclonal antibodies) have achieved promising results and are now often used to treat severe cases.

Objectives: To describe patients with initially misdiagnosed PTP[1] and to emphasize the diagnostic pitfalls of this disorder.

Patients and Results: During a period of 11 years we have diagnosed six patients with PTP, four women and two men. The incidence of PTP was approximately 1:24,000 blood components transfused. We present the detailed clinical course of three of the six patients in whom the diagnosis was particularly challenging. The patients were initially misdiagnosed as having heparin-induced thrombocytopenia, systemic lupus erythematosus complicated by autoimmune thrombocytopenia, and disseminated intravascular coagulation. A history of recent blood transfusion raised the suspicion of PTP and the diagnosis was confirmed by appropriate laboratory workup.

Conclusions: PTP seems to be more frequent than previously described. The diagnosis should be considered in the evaluation of life threatening thrombocytopenia in both men and women with a recent history of blood transfusion.