Detection of Antinuclear Antibodies in Canine Serum by Immunoperoxidase in MDCK and Indirect Immunofluorescence in HEp2 Cells

Antinuclear antibodies are found in animals suffering from Systemic Lupus Erythematosus (SLE) and some other diseases, their presence in the blood is determined by antinuclear antibody (ANA) test using indirect immunofluorescence (IF) with HEp2 cells as a substrate. In this work, an immunoperoxidase (IP) assay was developed to evaluate the ANAs in canine sera, using canine kidney cell lines (MDCK) and compared with a commercial immunofluorescence test on Hep2 cells for this system, a fluoresceinated anti-canine Ig antibody was standardized. The study was performed on 50 sera from dogs submitted to the laboratory with different clinical diagnoses of autoimmune-associated diseases. The procedures on both cells were unified to perform comparisons of the reactions, direct sera or at different dilutions were added to a monolayer of permeabilized MDCK cells, followed by a peroxidized anti-canine IgG conjugate, and a substrate for the IP reaction. The same sera were tested on the commercial IF assay on Hep2 cell system. In 22/50 cases, the presence of LE cells in peripheral blood was determined. A high correlation was found in the detection of antinuclear antibodies between both cell lines and techniques, however there were differences in the reaction patterns in the nucleus and cytoplasm between cell lines. The diffuse nuclear pattern observed in MDCK cells was more related to the presence of high percentages of LE cells in peripheral blood. The differences found in the results were possibly associated with the presence of homologous antigens between the MDCK cells and the dog. In addition, the methodology and standardization for the use and interpretation of a reference serum was developed to unify the interpretation criteria in the laboratory.

Cytomegalovirus Infection in Children's Liver Tissues

Immunoperoxidase histochemical assay with monoclonal antibody against human cytomaglovirus (HCMV) was used to detect immediate early antigen (IEA) and early antigen (EA) of HCMV infection in liver tissue of 72 podiatric cases (34 autopsies and 38 biopsies). The HCMV antigen was positive in 25 % (18/27). Among them, 12 cases were both HCMV-IEA and EA positive; 4 were HCMV-IEA positive and 2 HCMV-EA positive only. Liver HCMV infection rate in neonates, the infants with the age <1 year and >l year was 8. 0 %,60. 0 %, and 14. 8 %, respectively, indicating that liver HCMV infectioh occurred at various ages. The liver HCMV infection rate in different diseases was 50. 0 % in infantile hepatitis syndrome; 70. 0 % in extrabiliary malformation, and 12. 5 % in other hepatopathies, suggesting that infantile hepatitis syndrome and extrabiliary malformation were related with HCMV infection in liver tissues.

Echovirus 18 Infection Is Associated with Crohn’s Disease

Background: Enterovirus (EV) can cause gastroenteritis and are known to replicate in Peyer’s patches of terminal ileum. EV has been found in the intestinal specimens from immunocompromised patients with regional enteritis, and another study demonstrates the presence of enterovirus in the resected terminal ileum of immunocompetent pediatric patients with Crohn’s disease (CD). Cluster outbreaks of CD have also been reported in the literature but the cause of the disease remains elusive. Materials and Methods: A small cluster of pathologically proven CD occurred in our geographic area in 2004-2005, concurrently with an epidemic of Echovirus 18 (E18) meningitis. Serum samples of these and other CD patients and control subjects were tested for neutralizing antibodies of 11 common typeable enteroviruses and Echovirus 18;and tissue samples of CD patients, and terminal ileum and colon biopsies of normal controls were tested for the presence of viral capsid protein 1 (VP1) by immunoperoxidase staining. Results: Immunoperoxidase staining demonstrated VP1 in a rare epithelial granuloma, in diseased muscle of terminal ileum and also in colon biopsies of CD patients. Significantly elevated E18 neutralizing antibody was found in patients with pathologically-proven Crohn’s disease, as compared to control subjects. Conclusion: In this small observational study, EV VP1 is consistently demonstrated in tissue samples of CD patients as compared to control subjects;and neutralizing antibody for E18 was found in all of the patients with available serum samples. Larger cross-sectional studies will be needed to define the role of E18 in this chronic disease.

Early Syphilis Presenting as Thickened Penile Plaques With an Embedded Recurrent Ulcer (Chancre Redux): A Case Report

Introduction:The manifestations of syphilis are varied,and serology can establish the diagnosis early,especially in rare cases.We report a case of chancre redux(a rare recurrence of primary syphilis),which was embedded within a secondary syphilitic penile skin plaque.There were missed opportunities at earlier diagnosis as serology for syphilis was not ordered.Case presentation:A 56-year-old man presented with thickened penile plaques for five months.He reported a small penile ulcer approximately one month prior.There was no history of other skin lesions or rash.However,clinically there was an asymptomatic,indurated ulcer embedded within a plaque which was swab-positive for syphilis by PCR.A punch biopsy of a plaque was spirochaete-positive using an immunoperoxidase stain.The patient’s lesions resolved three weeks after treatment with intramuscular benzathine penicillin.Discussion:Uncommonly reported even in the preantibiotic era,chancre redux is now rare.The ulcer usually recurs at or near the site of the original chancre,and has similar morphological features.The skin lesions of secondary syphilis can exhibit remarkable morphological variety.The most common skin manifestation,a generalized macular rash,was not present at any time in this case.Rather,there were only a couple of nonspecific penile plaques.If biopsy is performed,histologic findings are variable,though typically the inflammatory infiltrate includes plasma cells.A special immunoperoxidase stain can highlight spirochaetes in biopsy sections.Conclusion:This case highlights the importance of considering syphilis in the differential diagnosis of persistent,atypical penile lesions and underscores the need for appropriate serological testing in such instances.