Screening markers for chronic atrophic gastritis in Chiapas, Mexico.

Intestinal-type gastric adenocarcinomas usually are preceded by chronic atrophic gastritis. Studies of gastric cancer prevention often rely on identification of this condition. In a clinical trial, we sought to determine the best serological screening method for chronic atrophic gastritis and compared our findings to the published literature. Test characteristics of potential screening tests (antibodies to Helicobacter pyloni or CagA, elevated gastrin, low pepsinogen, increased age) alone or in combination were examined among consecutive subjects enrolled in a study of H. pylori and preneoplastic gastric lesions in Chiapas, Mexico; 70% had chronic atrophic gastritis. English-language articles concerning screening for chronic atrophic gastritis were also reviewed. Sensitivity for chronic atrophic gastritis was highest for antibodies to H. pylori (92%) or CagA, or gastrin levels >25 ng/l (both 83%). Specificity, however, was low for these tests (18, 41, and 22%, respectively). Pepsinogen levels were highly specific but insensitive markers of chronic atrophic gastritis (for pepsinogen I <25 microg/l, sensitivity was 6% and specificity was 100%; for pepsinogen I:pepsinogen II ratio <2.5, sensitivity was 14% and specificity was 96%). Combinations of markers did not improve test characteristics. Screening test characteristics from the literature varied widely and did not consistently identify a good screening strategy. In this study, CagA antibodies alone had the best combination of test characteristics for chronic atrophic gastritis screening. However, no screening test was both highly sensitive and highly specific for chronic atrophic gastritis.

Association of Epstein-Barr virus in epithelioid angiomatosis of AIDS patients.

Epithelioid angiomatosis, hemangioma-like vascular proliferations recently described in AIDS patients, has been associated with the cat scratch disease bacillus. Other vascular lesions present in AIDS patients, in particular Kaposi's sarcoma, have been associated with cytomegalovirus (CMV). We investigated the possibility of viral association with epithelioid angiomatosis by analyzing two such lesions, as well as unrelated concurrent skin lesions, for the presence of viral genetic information. Colorimetric in-situ hybridization was performed on formalin-fixed, paraffin-embedded sections using cloned biotinylated probes for CMV, herpes simplex virus, human immunodeficiency virus, and Epstein-Barr virus (EBV). The only virus demonstrated was EBV, and this was only in the two epithelioid angiomatosis lesions. Hybridization signal for EBV was present in the nuclei of endothelial cells and occasional histiocytes. Bacilli were demonstrated within one of the lesions by silver stain. This is the first report associating EBV with this entity, and the first-time demonstration of EBV genetic information in endothelial cells. Our data suggest that these vascular lesions may represent a nonspecific response to infection by many different agents, and that EBV may be involved in the pathogenesis of some of these lesions.

Gastric atrophy and extent of intestinal metaplasia in a cohort of Helicobacter pylori-infected patients.

Atrophy and intestinal metaplasia (IM) are preneoplastic gastric lesions associated with Helicobacter pylori infection. Atrophy and IM are usually found together; however, the association between increasing degrees of severity of both atrophy and IM has not been evaluated completely. Two pathologists graded atrophy and IM using the visual analog scale of the Sydney classification in gastric biopsies from 368 H pylori-infected patients. Extent of IM also included determining the number of specimens affected. We then correlated the degree of atrophy with the degree and number of specimens affected with IM by calculating relative risks (RR) and 95% confidence intervals (95% CI). The mean number of biopsies examined from each patient was 6.5. Atrophy and IM were found more frequently in the antrum (85% and 75% of biopsies, respectively). One hundred thirty-eight patients had a combination of atrophy and IM, 48 had IM only, and 89 had atrophy only. Fifty-three subjects had mild atrophy and IM (RR = 1.57; 95% CI 1.2-2.1), 69 had moderate atrophy and IM (RR = 1.86; 95% CI 1.9-2.4), and 16 had marked atrophy and IM (RR = 2.47; 95% CI 1.8-3.3). The median number of biopsy specimens with IM increased from 0 in subjects with no atrophy to 3 in subjects with severe atrophy. The degree of IM correlated with the degree of atrophy; the median degree was 0.6 in subjects with no atrophy and increased to 2.32 in those with severe atrophy. Our data suggest that higher degrees of IM in an individual specimen and increasing number of specimens with IM are associated with moderate or severe degrees of atrophy.

Interobserver variability in application of the revised Sydney classification for gastritis.

The Sydney classification for gastritis provides guidelines for histological grading of gastric biopsies. In an ongoing study of gastric preneoplastic lesions in Chiapas, Mexico, 7 biopsies from 150 patients (4 from the antrum and 3 from the body) were obtained during endoscopy and studied histologically. The first 74 endoscopy specimens were read independently by 2 general surgical pathologists. We assessed diagnostic concordance using kappa statistics. The 2 pathologists then jointly reviewed biopsies about which they had disagreed to reach a final diagnosis. A second group of 76 endoscopies was subsequently evaluated independently by the 2 pathologists, and concordance was again assessed. In the first group of biopsies, we found low concordance rates (Heliobacter pylori 0.59, acute inflammation 0.22, intestinal metaplasia 0.60, and atrophy 0.04). In the second group, of independently reviewed cases, there was better concordance (H pylori 0.77, acute inflammation 0.50, intestinal metaplasia 0.70, and atrophy 0.64). We presumed that use of the Sydney classification would result in minimal interpretational differences achieving ideal kappas greater than 0.80. Because pathology results are based on subjective interpretation of this classification, complete diagnostic agreement is practically impossible. Concordance by general surgical pathologists after joint review of cases was similar to that obtained by gastrointestinal pathologists.

Leptospirosis mimicking acute cholecystitis among athletes participating in a triathlon.

Leptospirosis, a disease acquired by exposure to contaminated water, is characterized by fever accompanied by various symptoms, including abdominal pain. An acute febrile illness occurred in athletes who participated in an Illinois triathlon in which the swimming event took place in a freshwater lake. Of 876 athletes, 120 sought medical care and 22 were hospitalized. Two of the athletes had their gallbladders removed because of abdominal pain and clinical suspicion of acute cholecystitis. We applied an immunohistochemical test for leptospirosis to these gallbladders and demonstrated bacterial antigens staining (granular and filamentous patterns) around blood vessels of the serosa and muscle layer. Rare intact bacteria were seen in 1 case. These results show that leptospirosis can mimic the clinical symptoms of acute cholecystitis. If a cholecystectomy is performed in febrile patients with suspicious environmental or animal exposure, pathologic studies for leptospirosis on formalin-fixed, paraffin-embedded tissues may be of great value.

Multiple arteriovenous malformations of the small intestine in a patient with protein S deficiency.

The authors report a case of arteriovenous malformations (AVMs) of the small intestine in a young patient with protein S deficiency. These disorders have not been previously reported to occur together. Protein S deficiency may cause thromboses in unusual sites, including the mesenteric veins. Several mechanisms linking protein S deficiency to the occurrence of AVMs in this patient are offered.

Immunohistochemical and in situ hybridization studies of influenza A virus infection in human lungs.

Influenza viruses are responsible for acute febrile respiratory disease. When deaths occur, definitive diagnosis requires viral isolation because no characteristic viral inclusions are seen. We examined the distribution of influenza A virus in tissues from 8 patients with fatal infection using 2 immunohistochemical assays (monoclonal antibodies to nucleoprotein [NP] and hemagglutinin [HA]) and 2 in situ hybridization (ISH) assays (digoxigenin-labeled probes that hybridized to HA and NP genes). Five patients had prominent bronchitis; by immunohistochemical assay, influenza A staining was present focally in the epithelium of larger bronchi (intact and detached necrotic cells) and in rare interstitial cells. The anti-NP antibody stained primarily cell nuclei, and the anti-HA antibody stained mainly the cytoplasm. In 4 of these cases, nucleic acids (ISH) were identified in the same areas. Three patients had lymphohistiocytic alveolitis and showed no immunohistochemical or ISH staining. Both techniques were useful for detection of influenza virus antigens and nucleic acids in formalin-fixed paraffin-embedded tissues and can enable further understanding of fatal influenza A virus infections in humans.

Mouse model for Chagas disease: immunohistochemical distribution of different stages of Trypanosoma cruzi in tissues throughout infection.

Different stages of Trypanosoma cruzi are seen during mammalian infection. Histologic sections of infected hearts have shown amastigotes and, when using immunohistochemistry (IHC), parasite antigens; however, demonstration of trypomastigotes in these tissues has proven elusive. Using a mouse strain that develops chagasic cardiomyopathy (histologically similar to human infection) 70 days after injecting T. cruzi-Brazil strain, we studied the distribution of parasite stages and the extent of inflammation. All organs had varying amounts of mononuclear inflammation by day 10, which peaked between day 20 and day 30, and decreased by day 50. Amastigotes were detected in myocytes, histiocytes, acinar pancreatic cells, astrocytes and ependymal cells by day 10, and the number of amastigotes peaked on day 30. Immunohistochemistry demonstrated trypomastigotes in sinusoids, vessels and interstitial tissues of several organs between day 15 and 50. Abundant parasite antigens (granular staining) were detected in connective tissues throughout the infection. The burden of amastigotes and trypomastigotes during the acute phase seems to correlate with the degree of inflammation and granular staining in the chronic stage.

An outbreak of plague including cases with probable pneumonic infection, Ecuador, 1998.

During February and March of 1998, 12 sudden deaths were reported among residents of a high-Andean community in Ecuador. All 12 fatalities were members of the same extended family and some had apparent exposure to sick guinea-pigs. Following an initial investigation by public health officials, an additional death was reported in a nearby community in April, also associated with exposure to sick guinea-pigs. Blood samples from humans, dogs, and a rodent were tested for antibody to the F1 antigen of Yersinia pestis by passive haemagglutination assay. Tissue from rodents was subjected to direct fluorescent antibody staining using fluorescein-labelled monoclonal antibody to Y. pestis F1 antigen. Formalin-fixed specimens from the 2 autopsies were evaluated using a 2-step alkaline phosphatase immunoassay with a monoclonal antibody to Y. pestis F1 antigen, and tissues that had not been embedded in paraffin were tested for the presence of DNA encoding the F1 structural antigen by polymerase chain reaction. Serological evaluation of close contacts of the fatalities revealed positive titres to F1 antigen of Y. pestis, the aetiological agent of plague, in 3 contacts from the first community and 1 from the second. Immunohistochemical staining of tissues collected from 2 of the fatalities provided evidence that both had pneumonic plague. Five of 14 dogs found in the communities were seropositive for plague antibody, providing evidence of a recent epizootic plague in the area.

Frequency of intestinal parasites in adult cancer patients in Mexico.

Approximately 28% of the Mexican population has intestinal parasites. Oncologic patients receiving chemotherapy should have a coproparasitoscopic study to avoid disseminated parasitic infections. The frequency of intestinal parasites, including Cryptosporidium and Isospora, was evaluated in 100 diarrheic (DS) and 100 formed stools (FS) from adult patients recently diagnosed with cancer, using wet mounts stained with Kinyoun, saccharose and ZnSO4 procedures stained with Lugol's iodine. Seven patients with DS and three with FS had more than one parasite. Pathogenic intestinal parasites were seen in 26% of DS and 15% of FS. Of the frequent parasites, Entamoeba histolytica was found in 12 DS and in 2 FS (p = 0.01), Giardia lamblia in three DS and six FS and Hymenolepis nana in eight DS and 10 FS. Other pathogenic parasites were found only in DS: Cryptosporidium sp. in five patients, Ascaris lumbricoides in two, Strongyloides stercoralis in two and Isospora sp. in one. Cryptosporidium and Isospora were only identified by wet mounts stained with Kinyoun while other parasites were identified by flotation procedures. Since six (3%) of our patients had coccidia, the laboratory must perform special techniques for their detection. In epidemiologic settings where there is a high prevalence of intestinal parasitic infections the coproparasitoscopic studies should be performed and antiparasitic treatment provided before starting chemotherapy.

Ca 15.3 in breast cancer: comparison of two assays and validation in a Mexican population.

Ca 15.3 is a tumor marker used for breast carcinoma, since one epitope is an antigen present in milk fat globules. Serum from 171 patients with breast cancer upon initial presentation was studied for Ca 15.3. In the first 72 cases, the authors compared RIA vs. ELISA using a simple linear regression. On the following 99, only ELISA was performed. With all 171 patients, a clinical association between Ca 15.3 measurement and age, stage and hormone receptors was carried out. Correlation coefficient between RIA and ELISA was 0.85. Of 104 patients below 50 years of age, 88 had normal Ca 15.3 and 16, elevated; 67 were older than 50 years, 46 had normal Ca 15.3 and 21, elevated (p=0.022). Ca 15.3 was elevated in 11% of patients with clinical stages I/II, and 89% in stages III/IV (p=0.0001). The association of Ca 15.3 with hormone receptors was not significant. In conclusion, ELISA and RIA measure Ca 15.3 with comparable results, the first method has the advantage of not using radioactivity. The authors found higher probability of elevated Ca 15.3 in older patients and in those with advanced disease.

Chronic myelocytic leukemia in accelerated phase with i(17) (q10) and loss of p53 gene. Case report.

Chronic myelogenous leukemia (CML) is a clonal disorder that presents with a stable period followed by an accelerated phase. The most frequent chromosomal abnormality described is t(9;22). Alterations of chromosome 17, where p53 is located, have been described during transformation. We studied a 23-year-old male who presented with chronic myelogenous leukemia. The karyotype demonstrated 46,XY,t(9;22) (q34;q11) in 12% of mitoses and hyperdiploidy in 43%. Forty-six months later the patient suffered a blast crisis characterized by absolute basophilia; the cytogenetic study demonstrated 48,XY,+8,t(9;22) (q34;q11), +der(22)t (9;22) (q34;q11), +i(17)(q10) in 18% of the mitoses, 46,XY, t(9;22) (q34;q11) in 34% and hyperdiploidy in 23%. Since there was i(17)(q10) during this stage, a retrospective DNA study of the biopsy material before and after the transformation was performed. In the chronic phase, p53 was present in normal amounts, during transformation there was loss of genetic material from the p53 region. The protein product of suppressor gene p53 normally works holding the proliferation of cells. When there is the formation of an isochromosome, genetic material is lost; thus, in this patient, p53 was deleted upon the observation of i(17). Lastly, this case shows how DNA can be extracted from slides; this technique is novel and can be used for retrospective studies when paraffin blocks or fresh tissue are not available.

A comprehensive review of the natural history of Helicobacter pylori infection in children.

Across populations of children, Helicobacter pylori prevalence ranges from under 10% to over 80%. Low prevalence occurs in the U.S., Canada, and northern and western Europe; high prevalence occurs in India, Africa, Latin America, and eastern Europe. Risk factors include socioeconomic status, household crowding, ethnicity, migration from high prevalence regions, and infection status of family members. H. pylori infection is not associated with specific symptoms in children; however, it is consistently associated with antral gastritis, although its clinical significance is unclear. Duodenal ulcers associated with H. pylori are seldom seen in children under 10 years of age. H. pylori-infected children demonstrate a chronic, macrophagic, and monocytic inflammatory cell infiltrate and a lack of neutrophils, as compared with the response observed in adults. The effect of H. pylori infection on acid secretion in children remains poorly defined. The events that occur during H. pylori colonization in children should be studied more thoroughly and should include urease activity, motility, chemotaxis, adherence, and downregulation of the host response. The importance of virulence determinants described as relevant for disease during H. pylori infection has not been extensively studied in children. Highly sensitive and specific methods for the detection of H. pylori in children are needed, especially in younger pediatric populations in which colonization is in its early phases. Criteria for the use of eradication treatment in H. pylori-infected children need to be established. Multicenter pediatric studies should focus on the identification of risk factors, which can be used as prognostic indicators for the development of gastroduodenal disease later in life.

Fungal peritonitis caused by Curvularia lunata in a patient undergoing peritoneal dialysis.

The authors present a case of a patient undergoing continuous ambulatory peritoneal dialysis (CAPD) who developed peritonitis with Curvularia lunata and gram negative Enterobacteriaceae. A review of the literature indicates that human infections caused by Curvularia are uncommon despite the ubiquity of the organism in the environment. In this case, the organism was present in the Tenckhoff catheter, lacking attachment to it, but obstructing the flow. Treatment of fungal peritonitis during CAPD is discussed.

Mammary Paget's disease and associated carcinoma. An immunohistochemical study.

Mammary Paget's disease has been said to result from epidermal spread by contiguity of primary intraductal carcinoma. To assess similar identity, we immunostained Paget's cells and underlying intraductal and/or invasive mammary carcinoma in 20 cases for cytokeratins, epithelial membrane antigen, gross cystic disease fluid protein-15, lysozyme, carcinoembryonic antigen, S100 protein, kappa-casein, and alpha-lactalbumin. Steroid receptor immunostain was positive in only one (5%) of the cases of Paget's disease and in two and four (approximately 15%) (for estrogen and progesterone receptor, respectively) of the cases of ductal carcinoma. In 18 patients (90%), the immunohistochemical profile was identical in Paget's cells and associated carcinoma for seven or more antigens. In one patient, there was a definite disparity in the antigenic profile; in another patient, this was dissimilar because of very focal staining in one site. The antigenic similarity between Paget's cells and underlying carcinoma in 18 (90%) of the cases of mammary Paget's disease suggested in favor of their common origin, ie, probably intraepidermal spread of ductal carcinoma. Origin from apocrine/eccrine structures, or multipotent cells in the epidermis, was suggested in a minority.

Sputum examination in the diagnosis of Pneumocystis carinii pneumonia in the acquired immunodeficiency syndrome.

To examine the role of sputum examination in the diagnosis of Pneumocystis carinii pneumonia in patients with the acquired immunodeficiency syndrome (AIDS), we conducted a prospective study of 30 patients with AIDS or suspected AIDS. Sputum was obtained just prior to bronchoscopy by spontaneous cough (20 patients) or by induction with a saline nebulizer (ten patients). Pneumocystis carinii was diagnosed by bronchoalveolar lavage in 13 of the 30 patients; two of these patients had P carinii organisms identified in sputum specimens (sensitivity of sputum, 15.3%; negative predictive value, 60.7%). A cost-analysis study demonstrated that sputum examination is not cost effective when the sensitivity is below 24%. We conclude that P carinii can be diagnosed from expectorated sputum in patients with AIDS, but, because of the test's low sensitivity, it cannot be recommended in the routine evaluation of patients with AIDS and pulmonary complaints.

Biclonal gammopathy (IgG kappa and IgG lambda) in a patient with non-Hodgkin's lymphoma.

We report a case of non-Hodgkin's malignant lymphoma with biclonal gammopathy (IgG kappa and IgG lambda) involving both serum and urine. Detailed immunologic studies of the tumor disclosed two morphologically indistinguishable clones of cells that were responsible for the production of the two monoclonal immunoglobulins. This, to our knowledge, is the first documented case of a biclonal gammopathy involving a single heavy-chain class with both kappa and lambda light chains in a non-Hodgkin's lymphoma. Lesions resembling lymphomas must not be assumed to be inflammatory simply because the cells express both kappa and lambda antigens.

Primary non-Hodgkin's lymphoma of the heart in two patients with the acquired immunodeficiency syndrome.

We report two cases of primary cardiac lymphoma that developed in patients suffering from the acquired immunodeficiency syndrome. Both cases of lymphoma were histologically aggressive as generally observed in patients with the acquired immunodeficiency syndrome. The lymphoma cells in the center of a tumor nodule obtained from one patient were monoclonal B-cells, whereas those at the periphery showed a polyclonal pattern of staining. It is postulated that this represents a monoclonal lymphoma evolving from a polyclonal B-cell lymphoproliferation analogous to those reported in some cases of lymphoma in immunosuppressed patients infected with Epstein-Barr virus. The lymphoma cells in the other case failed to stain for cytoplasmic immunoglobulins. The possible underlying basis for the increase in incidence of lymphoma in immunodeficiency and the reasons for prevalence of extranodal sites are discussed.

Cytologic detection of Pneumocystis carinii: a comparison of Papanicolaou and other histochemical stains.

Pneumocystis carinii, a common pathogen among immunocompromised patients, has been investigated in cytologic specimens using both the histochemical stains and ultraviolet (UV) fluorescence following Papanicolaou staining. We reviewed 57 pulmonary cytologic specimens obtained from 23 patients and compared the results of specific histochemical stains and Papanicolaou-stained preparations under UV excitation. Specific Pneumocystis fluorescence was observed in 26 of 49 Papanicolaou-stained specimens. Thirty-seven specimens were examined using both histochemical staining and after Papanicolaou UV staining. A comparison of the two techniques showed the Papanicolaou UV technique to have 89% sensitivity and 95% specificity. Cellulosic filters were the most valuable Papanicolaou-stained preparation for Pneumocystis diagnosis. The authors conclude that UV fluorescence of Papanicolaou-stained specimens obtained by noninvasive procedures is a rapid, accurate, and economical method for diagnosing pulmonary Pneumocystis carinii infections.

Vulvar Paget's disease. Cytologic and immunohistologic diagnosis of a case.

An exfoliative smear from the vagina in a case of vulvar Paget's disease extending into the vagina and urethra was cytologically diagnosed as showing a large cell carcinoma. The malignant cells proved to be Paget cells by comparison of the cytologic specimen with subsequent biopsy specimens and by immunohistochemical studies using antibodies for glandular cytokeratin, epithelial membrane antigen, carcinoembryonic antigen and gross cystic disease fluid protein. These studies demonstrated that the Paget cell is probably of apocrine derivation. Exfoliative cytology and immunohistochemistry of exudative vulvar lesions may be helpful in the identification of Paget cells.