Sara Bonetto

Focal gastric inflammatory infiltrates in inflammatory bowel diseases : Prevalence, immunohistochemical characteristics, and diagnostic role

OBJECTIVES:To date, few studies have evaluated gastric histology in patients with inflammatory bowel disease (IBD). The aim of this prospective controlled study was to establish the frequency of focal gastritis in Crohns disease (CD) and ulcerative colitis (UC) patients, as well as to evaluate its immunohistochemical characteristics and clinicoanatomical determinants.METHODS:We evaluated 141 consecutive patients with known CD of the large and/or small bowel, 79 patients with UC, and 141 CD- and UC-free controls; all underwent upper gastrointestinal (GI) endoscopy and 13C urea-breath test. Biopsy specimens taken from the antrum, angulus, and gastric body were evaluated by histology and immunohistochemistry. A series of variables, including CD activity index, duration, extent and location of disease, intestinal resection, number of recurrences, and previous and current medical therapy, as well as the presence of dyspeptic symptoms and mucosal lesions at endoscopy, were determined in all CD patients and correlated with the presence or absence of focal gastritis.RESULTS:Helicobacter pylori-associated gastritis was found in 47 patients with CD (33%), in 37 patients with UC (47%), and in 60% of CD-/UC-free controls (p < 0.01). In H. pylori-negative CD patients focal gastritis was found in 43% of cases (40/94), compared with 12% (5/42) of UC patients and 19% (11/57) of controls (p < 0.05). Specificity and positive predictive value of focal gastritis in CD were 84% and 71%, respectively. It was characterized by a focal perifoveolar or periglandular lymphomonocytic infiltrate, with CD8+/CD4+ cells predominant both in CD and UC patients. There were no significant correlations between the occurrence of focal gastritis and any clinicoanatomical CD features.CONCLUSIONS:Focal gastritis is relatively common in CD patients although it is not exclusive to this condition. Its recognition could be useful in the diagnostic workup of any patient with suspected or indeterminate inflammatory bowel disease, as it makes a diagnosis of CD more likely.

Disseminated Microsporidiosis Caused by Encephalitozoon cuniculi III (Dog Type) in an Italian AIDS Patient: a Retrospective Study

We report a case of disseminated microsporidiosis in an Italian woman with AIDS. This study was done retrospectively using formalin-fixed, paraffin-embedded tissue specimens obtained at autopsy. Microsporidia spores were found in the necrotic lesions of the liver, kidney, and adrenal gland and in ovary, brain, heart, spleen, lung, and lymph nodes. The infecting agent was identified as belonging to the genus Encephalitozoon based on transmission electron microscopy and indirect immunofluorescence. Additional molecular studies, including sequence of the rDNA internal transcribed spacer region, identified the agent as E. cuniculi, Genotype III. We believe that this is the first report of a human case of disseminated microsporidial infection involving the ovary.

Beta amyloid precursor protein and patterns of HIV p24 immunohistochemistry in different brain areas of AIDS patients.

ObjectivesTo evaluate the correlation between immunohistochemical positive patterns (globular and filamentous structures) of β-amyloid precursor protein (β-APP), used as a marker of axonal damage, and the different distribution of HIV p24 antigens, in three different brain areas of AIDS patients. MethodsEighteen AIDS patients with HIV-related brain lesions were included in the study. Forty-nine sections from basal ganglia, frontal cortex and hippocampus were selected. After microwave oven pre-treatment, the sections were incubated with anti-HIV p24 and anti-β-APP monoclonal antibodies; the reactions were developed with peroxidase/3,3′diaminobenzidine. The positivity was graded by semi-quantitative scores. Double immunohistochemical staining was used to evaluate the co-localization of the antigens. ResultsHIV p24 immunohistochemistry was positive in 44 of 49 sections (89%), with a prevalence of interstitial positive cells and positive microglial nodules in 27 and 13 sections respectively. β-APP-positive structures were demonstrated in 23 of 44 sections (52%) with HIV-related lesions, and were absent from the five sections without viral expression. Globular and filamentous lesions were observed in 21 of 23 sections and 10 of 23 lesions respectively. Moreover, a high grade of globular type lesion was related to an elevated presence of diffuse interstitial HIV p24-positive cells in basal ganglia; double immunohistochemical reactions demonstrated the co-localization of β-APP globules and HIV p24 antigens. ConclusionsThe data obtained confirm the coexpression of β-APP and viral antigens in particular areas of the brain with HIV-related lesions; there is a strict correlation between β-APP globules (indicating chronic cerebral damage) and the interstitial pattern of HIV p24 immunohistochemistry.

Pathological findings in the central nervous system of AIDS patients on assumed antiretroviral therapeutic regimens: retrospective study of 1597 autopsies

Objective: To evaluate the prevalence of HIV-related central nervous system (CNS) lesions (HIV-encephalitis and/or HIV-leukoencephalopathy: HIV-E/L) with and without concomitant opportunistic diseases in a large autopsy series, and to correlate it with the changes in antiretroviral treatment that have occurred since the beginning of the epidemic. Methods: We reviewed 1597 consecutive autopsies of HIV-positive patients performed between 1984 and 2000, and divided into four time periods on the basis of the therapeutic regimens available: 1984–1987, no therapy; 1988–1994, monotherapy (zidovudine); 1995–1996, dual combination therapy with nucleoside reverse transcriptase inhibitors (NRTI); and 1997–2000, triple combination therapy including two NRTI and at least one protease inhibitor or non-NRTI. The data concerning the treatment actually received were collected only for the patients who died during the last period. The χ2-test was used to assess the significance of the differences in prevalence. Results: The CNS of 1210 patients (76%) was affected by opportunistic diseases, HIV-related lesions or both. The prevalence of HIV-related lesions in the four periods was respectively 54%, 32%, 18% and 15%; this reduction was statistically significant (P < 0.000001). During the last period, however, differences in HIV-E/L between treated and untreated patients were not statistically significant, although there were fewer than expected cases among the treated patients (six instead of eight) and more than expected among the untreated patients (10 instead of eight). Conclusions: These neuropathological data from a large autopsy series confirm clinical observations concerning the efficacy of antiretroviral treatment in reducing the frequency of HIV-related CNS lesions in AIDS patients.

BK virus renal infection in a patient with the acquired immunodeficiency syndrome.

BACKGROUND We describe herein a patient with the acquired immunodeficiency syndrome and renal failure due to biopsy-proven BK virus (BKV) infection. Three months after the diagnosis of the renal viral infection, his condition remained unchanged. Although BKV has previously been shown to be associated with ureteral stenosis and renal damage in renal transplant patients, to our knowledge, the literature contains only 3 cases describing the presence of BKV lesions in the kidneys of immunosuppressed patients who had not undergone transplantation. METHODS The presence of BKV infection was demonstrated by means of histology, immunohistochemistry with polyclonal anti-SV40 antibody, immunoelectron microscopy, polymerase chain reaction, and enzymatic cleavage with BamHI. RESULTS Histologic examination revealed interstitial inflammatory infiltrates and tubules with enlarged and eosinophilic nuclei. CONCLUSIONS The high frequency of latent BKV infection and its reactivation during immunosuppression suggest that the possibility of its involvement in renal damage should be considered in immunocompromised patients.

Coinfection of the central nervous system by cytomegalovirus and herpes simplex virus type 1 or 2 in AIDS patients: autopsy study on 82 cases by immunohistochemistry and polymerase chain reaction

Abstract We evaluated the frequency and histopathological features of concomitant infections of the central nervous system (CNS) with cytomegalovirus (CMV) and herpes simplex viruses type 1 or 2 (HSV1/2) in a large series of patients who had died from AIDS. Eighty-two autopsy cases with a histological diagnosis of CMV necrotizing encephalitis were examined retrospectively. CMV and HSV1/2 were detected by immunohistochemistry (IHC) with poly- and monoclonal antibodies and by nested polymerase chain reaction (PCR) for HSV 1 and 2 on DNA extracted from paraffin blocks. PCR for a β-globin genomic sequence was performed in all IHC-positive cases to verify the integrity of extracted DNA. Concomitant CMV/HSV infections were demonstrated by IHC in 13 cases (16%); using monoclonal antibodies, HSV1 was found in 9 cases and HSV2 in 4 cases. In half of the cases, HSV1- or HSV2-positive cells represented more than 25% of immunopositive CMV cells. In all 13 cases, double immunochemical staining showed cells containing both CMV and HSV antigens. PCR for HSV1 and 2 was positive in only 7 of 13 cases (5 HSV1 and 2 HSV2). In the remaining 6 negative cases PCR for β-globin was also repeatedly negative. HSV1 or 2 infection can be demonstrated by IHC in a significant proportion of AIDS cases with necrotizing CMV encephalitis. Nested PCR for HSV1 and 2 on DNA extracted from formalin-fixed and paraffin-embedded autopsy tissues was positive in only slighty above 50% of IHC-positive cases.

Etiology of microglial nodules in brains of patients with acquired immunodeficiency syndrome

Microglial nodules associated with opportunistic and HIV-related lesions are frequently found in the brains of AIDS patients. However, in many cases, the causative agent is only presumptively suspected. We reviewed 199 brains of AIDS patients with micronodular lesions to clarify their etiology by immunohistochemistry (to Toxoplasma gondii, cytomegalovirus, herpes simplex virus I/II, varicella zoster virus and HIV-p24 core protein), PCR (for herpetic viruses and Mycobacterium tuberculosis) and electron microscopy. Productive HIV infection was observed in 110 cases (55.1%): 30 cases with Toxoplasma gondii encephalitis, 30 with cytomegalovirus encephalitis, eight with multiple cerebral diseases, while in the remaining 42 cases HIV was the only pathogenetic agent. Multinucleated giant cells (hallmark of HIV infection) were found in the MGNs of 85/110 cases with HIV-related lesions; the remaining 25 cases had only p24 positive cells but no multinucleated giant cells. In these latter cases the micronodular lesions had been initially attributed to the main opportunistic agent found in the brain, or defined as subacute encephalitis. Individual microglial nodules positive for an opportunistic pathogen were generally negative for HIV antigens. In 13 cases no opportunistic agent or HIV productive infection was found. In these cases, PCR and electron microscopy examination for HIV and other viral infections were negative. Our data suggest that HIV-immunohistochemistry should be used for the etiological diagnosis of micronodular lesions in AIDS brains, even in the presence of other pathogens. After extensive search, the etiology of the microglial nodules remains unknown in only a small percentage of cases.

VZV fulminant necrotizing encephalitis with concomitant EBV-related lymphoma and CMV ventriculitis: report of an AIDS case

A case of AIDS with varicella zoster virus fulminant necrotizing encephalitis associated with cytomegalovirus ependymitis-subependymitis and a periventricular Epstein-Barr virus-related lymphoma is described. The patient had no herpes zoster cutaneous eruptions and died three days after the onset of symptoms. Varicella zoster virus and cytomegalovirus antigens were found by immunohistochemistry in the same area around a necrotic periventricular lesion; a periventricular lymphoma, large B cell type, was also observed. In situ hybridization with Epstein-Barr virus-encoded- RNAs probe was positive in about 40% of the neoplastic cells. The association of herpes-related lesions in the same cerebral region should be consistent in AIDS cases with acute neurological symptoms.

Polymerase chain reaction for Mycobacterium tuberculosis complex DNA : Use on negative archival Ziehl-Neelsen cytologic samples

OBJECTIVE To evaluate the usefulness of a nested polymerase chain reaction (PCR) for Mycobacterium tuberculosis complex on routinely stained cytologic samples from patients with extrapulmonary tuberculosis. STUDY DESIGN Nested PCR for the detection of a fragment of the IS6110 insertion sequence of M tuberculosis complex was applied to Ziehl-Neelsen-negative archival cytologic slides of serous effusions (pleural [n = 7], peritoneal [n = 1] and pericardial [n = 1]) and a lymph node fine needle aspirate (n = 1) from nine human immunodeficiency virus (HIV)-positive patients with autopsy-proven active extrapulmonary tuberculosis. Malignant effusions and aspirates from nine HIV-positive patients with non-Hodgkins lymphoma and pleural effusions from seven HIV-negative patients with heart failure were used as controls. DNA was extracted after removing the coverslip and gently scraping the cytologic sample from the slides. RESULTS In all cases, enough DNA was obtained for PCR without any significant loss of integrity, as demonstrated by PCR positive for HLA-Dq. PCR for M tuberculosis was positive in 8 of the 10 samples (80%) from patients with tuberculosis but also in three samples (30%) from HIV-positive patients in the control group. None of the samples from the HIV-negative patients was positive. CONCLUSION PCR for M tuberculosis can be reliably performed on archival cytologic slides from extrapulmonary samples, but although it is highly sensitive, it may lead to positive results in immunocompromised patients without any sign of active tubercular disease.

Hepatic metastases from medullary thyroid carcinoma appearing twelve years after the eradication of primitive tumor: Cytological and radiological aspects

We report on radiological and cytological findings from a case of medullary thyroid carcinoma (MTC) metastatizing to the liver 12 yr after the eradication of the primary neoplasm. This behavior has never before been described in a sporadic form of MTC. Diagn. Cytopathol. 1999;21:43–45.