Immunohistochemistry to identify Leishmania parasites in fixed tissues.

The definitive diagnosis of leishmaniasis currently depends on the identification of characteristic amastigote morphology in tissue, or isolation of promastigotes by culture. Histopathological identification can be difficult, and is variably sensitive; culture is considered "the gold standard", but is not uniformly diagnostic or available. In this study, we compared light microscopic immunohistochemistry (IHC) using a monoclonal anti-Leishmania antibody (G2D10) to standard hematoxylin and eosin (H&E) stain in the diagnosis of Leishmania on skin. Sixty-one archived specimens from patients suspected of being infected with Leishmania were used; 41 of these had leishmaniasis confirmed by culture. Although not statistically significant, both sensitivity and specificity were higher for IHC compared to H&E: 51% (95% CI: 35-67%) compared to 42% (CI: 26-58%; 2p=0.29) for sensitivity, and 100% (CI: 83-100%) compared to 85% (CI: 62-97%, 2p=0.25) for specificity, respectively. Furthermore, because organisms could be diagnosed by IHC at low power (x20-40), this assay was more rapid than H&E, in which parasite morphology could best be identified at oil immersion power. The G2D10 antibody has broad Leishmania species recognition, and offers promise as a simple, rapid diagnostic screen for leishmaniasis. Further study is underway to better characterize this antibody.

Alveolar adenoma: a histochemical, immunohistochemical, and ultrastructural analysis of 17 cases.

Alveolar adenoma of lung is a rare benign neoplasm of uncertain histogenesis. Its rarity hampers characterization of its epithelial and mesenchymal elements. Clinical and histopathologic features of 17 alveolar adenomas were reviewed. Histochemistry was performed on 10 cases, ultrastructural analysis on two, and immunohistochemistry on six cases for pneumocyte markers, thyroid transcription factor (TTF-1), surfactant protein markers pro-SP-B and pro-SP-C, and the Clara cell marker, CC10. Immunohistochemistry was performed in nine cases for desmin, smooth muscle actin, muscle-specific actin, cytokeratin, proliferating cell nuclear antigen (PCNA), factor VIII, and carcinoembryonic antigen. The mean age was 53 years. Seven cases occurred in men, and nine occurred in women. The age and sex were not known for one patient. The tumors were coin lesions on chest radiographs in asymptomatic patients except for one (cough). The mean size was 2.2 cm. The tumors were well demarcated with multiple cystic spaces containing granular material. Mostly type 2 pneumocytes lined the cystic spaces with fewer type 1 cells and no Clara cells. This was confirmed by staining for TTF-1, pro-SP-B, and pro-SP-C and by ultrastructure. CC10 was negative in all cases. The stroma varied from prominent spindle cells with a myxoid matrix to thin alveolar septa. The interstitial spindle cells resembled fibroblasts by immunohistochemistry and ultrastructure. Follow-up data available in five cases showed no recurrence at 2, 2, 5, 8, and 13 years. In summary, alveolar adenoma is a benign neoplasm consisting of an intimate admixture of alveolar epithelial and septal mesenchymal tissue. Most of the epithelial cells are type 2 pneumocytes, and the interstitial stromal cells are fibroblasts or fibroblast-like cells. Recognition of its characteristic morphological appearance allows for its distinction from other benign lesions of the lung.

Pathological and biophysical findings associated with silicone breast implants: a study of capsular tissues from 86 cases.

Breast implant capsular tissues from 86 cases were studied to characterize the relationship between capsular findings and the type of implant used. Tissues were examined by light microscopy, immunohistochemistry, scanning electron microscopy/energy dispersive x-ray analysis and Fourier transform infrared, and Raman microspectroscopy. Capsular pathology was influenced by the structure and composition of the implant. A pseudoepithelium at the inner capsular surface (synovial metaplasia) was noted with silicone gel-filled, saline-filled, and polyurethane-coated implants, and disproportionatelywith textured surface implants. Immunohistochemical studies of pseudoepithelium supported a macrophage/histiocyte cellular origin. Talc was identified intracellularly within macrophages in 42 cases. Capsular calcification was strongly associated with the presence of implant stabilization patch material. Infrared spectra were used to identify silicone, talc, Dacron, and two different types of polyurethane in capsular tissues. Micropapillary structures identified at the pseudoepithelial surface have, to the authors' knowledge, not been previously described.

Papillary squamotransitional cell carcinoma of the cervix: a report of 32 cases.

Papillary carcinomas of the uterine cervix with transitional or squamous differentiation are rare tumors that often resemble transitional cell carcinomas of the urinary tract. We reviewed 32 such cases of papillary cervical carcinoma and divided them into three groups: 1) predominantly (> 90%) squamous (nine cases), 2) mixed squamous and transitional (16 cases), and 3) predominantly transitional (seven cases). Overall, the patients ranged in age from 22 to 93 years (mean 50), and the most common clinical presentation was abnormal bleeding (15 patients) and an abnormal Papanicolaou smear (nine patients). The tumors ranged in size from 0.7 to 6.0 cm (mean 3.0). All cases demonstrated a papillary architecture with fibrovascular cores lined by a multilayered, atypical epithelium resembling a high-grade squamous intraepithelial lesion of the cervix. Underlying superficial to deep stromal invasion was seen in 18 of 20 cases (90%); in the remaining 12 cases, the specimen was too superficial to assess invasion. Eighteen (86%) of the 21 cases examined immunohistochemically demonstrated immunoreactivity for cytokeratin 7, whereas only two of the 21 (9.5%) showed positivity for cytokeratin 20. Of the 12 women for whom follow-up information was available, three were treated by simple hysterectomy, two underwent radical hysterectomy, one was treated with radiation alone, and one with combination chemotherapy and radiotherapy. Three patients died of disease (two in the squamous group and one transitional) within an average of 13 months after diagnosis. Local recurrence developed in two women, and one of these, a vaginal recurrence, occurred 12 years after the original diagnosis. Based on the above findings, we believe that these tumors are a clinicopathologically distinct, homogeneous group that display a morphologic spectrum. Nevertheless, because some tumors may show a purely squamous or purely transitional appearance, we propose retaining the above three separate designations for these tumors with the understanding that there is often a substantial degree of subjectivity in deciding whether a tumor is squamous or transitional. The most distinctive, objective, and easily recognizable feature of these tumors is their surface papillary architecture rather than their superficial resemblance to transitional cell carcinomas of the urinary tract, and we emphasize the need to distinguish these potentially aggressive malignant tumors from the far more common and benign papillary lesions of the cervix.

Localization of human immunodeficiency virus 1 RNA in thymic tissues from asymptomatic drug addicts.

Thymic tissue was collected from 11 human immunodeficiency virus 1 (HIV-1)-seropositive drug users who died suddenly of drug intoxication or trauma. None of the 11 individuals had symptoms related to HIV-1 infection or were known to be seropositive for HIV-1 before death. Secondary B-cell follicles were present in every thymus, and Warthin-Finckeldey giant cells were noted in three cases. These follicles were enlarged or fragmented and appeared similar to those in lymph nodes excised from the same individuals. Localization of viral RNA by in situ hybridization demonstrated abundant virus in a follicular center cell distribution within hyperplastic follicles and in scattered medullary lymphocytes. In nine thymus glands from seronegative drug addicts and five thymus glands from seronegative trauma victims who were not drug addicts, secondary follicles were absent and no hybridization signal was present. Other than the presence of germinal centers associated with HIV-1 RNA, there were no histologic differences among the thymus glands of seropositive drug addicts, seronegative drug addicts, and seronegative controls without a history of drug abuse. We conclude that the thymus gland in early stages of infection with HIV-1 is characterized by induction of secondary B-cell follicular hyperplasia in medullary tissues, the germinal centers of which contain abundant viral RNA.

Simultaneous confirmation and differentiation of human T-lymphotropic virus types I and II infection by modified western blot containing recombinant envelope glycoproteins.

A modified Western blot (WB) that includes both shared (r21e) and unique recombinant envelope proteins from human T-lymphotropic virus (HTLV) type I (rgp46I) and type II (rgp46II) was compared to conventional HTLV serologic tests in 379 United States blood donors and individuals residing in diverse geographic regions, and the specimens were categorized as positive (n = 158), indeterminate (n = 158), or negative (n = 63) for HTLV infection. Of the 158 HTLV-I/II-positive specimens (66 requiring radioimmunoprecipitation assay [RIPA] for confirmation), 156 reacted concordantly with r21e, gag, and either rgp46I or rgp46II, thus eliminating the need for RIPA in all but two specimens and yielding a test sensitivity of 98.7 percent. Of the 158 indeterminate and 63 negative specimens, none reacted with r21e and rgp46I or rgp46II, yielding a test specificity of 100 percent. Furthermore, analysis of an additional 184 consecutive specimens from a retrovirology reference laboratory demonstrated that the modified WB correctly identified 27 of 28 HTLV-I specimens and all 13 HTLV-II specimens, with a test sensitivity of 97.6 percent. None of specimens that were indeterminate or nonreactive in conventional WB and/or RIPA and none of the screening enzyme immunoassay-negative specimens reacted with r21e and either rgp46I or rgp46II, for a test specificity of 100 percent. Thus, the modified WB appears to be highly sensitive and specific for simultaneous detection and discrimination of HTLV-I from HTLV-II and has the advantage of being a one-step assay that is easily performed in all types of laboratory settings and allows rapid, reliable, and standardized testing for HTLV-I/II infection.

Incidental myocarditis with intravenous drug abuse: the pathology, immunopathology, and potential implications for human immunodeficiency virus-associated myocarditis.

Human immunodeficiency virus (HIV)-associated myocarditis is well reported. Many of these patients are also intravenous (IV) drug abusers. This study examined sudden death victims from the Office of the Chief Medical Examiner, State of Maryland, for active myocarditis. A group of HIV-negative drug abusers is compared with a group of HIV-negative victims without any known risk factors for the acquired immunodeficiency syndrome. Using modified Dallas criteria combined with an avidin-biotin-labeled immunoperoxidase procedure, the cases were classified as active, borderline, or absent myocarditis. Serologic analysis for circulating antimyocardial antibody was performed along with phenotypic analysis of the infiltrate. Of the 15 IV drug abuse cases examined, none were positive for HIV (enzyme-linked immunosorbent assay and Western blot). With IV drug abuse as the primary risk factor, five cases demonstrated active myocarditis, while five others had borderline myocarditis. Only one of 10 low-risk patients had a lymphocytic infiltrate consistent with borderline myocarditis. Drug abuse-related myocarditis was associated with cardiac pathology resulting in sudden death in only one case. Antimyocardial antibodies were positive in four of the 15 IV drug abuse cases, including patients with active, borderline, and absent myocarditis. The phenotypic expression of the lymphocytic infiltrates was similar to the findings reported for idiopathic and HIV-related myocarditis (Am J Pathol 137:1365-1371, 1990). Toxicology studies did not implicate any particular drug of abuse, but the increased frequency of myocarditis observed may reflect complications of cocaine or the combined effects of opiates and cocaine. Intravenous drug abuse is an independent risk factor for myocarditis and must be taken into consideration in studies of HIV-associated myocarditis.

HIV-associated myocarditis. Pathology and immunopathology.

Autopsy studies of AIDS (acquired immune deficiency syndrome) patients showed a high incidence of myocarditis. To attain a better understanding of the pathogenesis, the pathology and immunopathology of nine endomyocardial biopsies with active myocarditis from 18 human immunodeficiency virus (HIV)-positive patients were systematically characterized. These were compared with 17 biopsies with active myocarditis from patients without AIDS risk factors. In both groups, the myocarditis consisted of either multifocal or interstitial infiltrates of small lymphocytes and isolated myocyte necrosis. The lymphocytes consisted of T cells (CD2+, CD3+) and cells not identified by the usual markers. B cells, monocytes, CD4+ cells, and natural killer (NK) cells were only rarely observed. All of the HIV-positive patients but only 7 of 17 non-HIV patients had CD8+ lymphocytes in the infiltrates (P less than 0.01). The arteriolar endothelium demonstrated induced class I (HLA-A, B, C) and II (HLA-DR) antigens in both groups. In situ hybridization for HIV-1 failed to identify the virus in the specimens. The immunopathology is consistent with a cell-mediated injury to the myocytes in HIV-positive patients and is similar to a subgroup of myocarditis in the non-HIV group.

Hypersensitivity to chromated catgut sutures: a case report and review of the literature.

Chromated catgut sutures are used extensively in general surgical procedures. Although delayed hypersensitivity reactions to this material are difficult to diagnose post-operatively--ie, they may be interpreted as non-specific complications of surgery--the condition can be readily evaluated by patch testing with chromate or intracutaneous placement of the actual suture material. Multiple reports in the literature suggested that there was an increased frequency of post-operative adhesions, wound dehiscence, infection, and even intestinal obstruction along the line of suture material to which the patient had been sensitized during a previous surgery. Particularly with the widespread availability of fully synthetic suture materials, which appear to be less sensitizing, an increased awareness of chromate hypersensitivity in patients undergoing repeated surgical procedures may decrease the frequency of subsequent inflammatory post-operative complications. We report a patient with a history of multiple abdominal surgical procedures, eosinophilic cystitis surrounding the suture material, prolonged post-operative pain, and inflammatory masses at the sites of previous surgery associated with a positive delayed hypersensitivity skin reaction to patch test chromate and to intradermal chromic catgut.