Ultrastructure of the polymorphonuclear leucocytes in human immunodeficiency virus infection.

The ultrastructure of polymorphonuclear leucocytes (PMNL) was studied in 16 patients infected with the human immunodeficiency virus (HIV). PMNL were isolated from HIV-infected patients with CD4+ lymphocytes counts > 200/mm3 (without signs of active infection) (n = 12) (group 1), or < 200/mm3 (n = 4) (group 2), and from 16 healthy volunteers (group 3). Immunoelectron microscopy staining using an anti-beta 2 integrin antibody (anti-CD18) was performed on PMNL from three individuals of group 2 and of three individuals of group 3, before and after incubation with N-formyl-methionyl-leucylphenylalanine (f-MLP). The radical oxygen intermediates (ROI) production of PMNL was investigated by luminol-mediated chemiluminescence. A number of ultrastructural abnormalities in PMNL were found in a higher proportion in HIV-infected patients. These were: (a) an increase in the size of the Golgi apparatus and in the number of mitochondria, and in the quantity of endoplasmic reticulum; (b) some dysplastic features including large cytoplamic vacuoles, whorl of myelin, and nuclear pockets; (c) an increase prevalence of multivesicular bodies compared with control PMNL; (d) some cylindrical confronting cisternae and tubuloreticular structures. After anti-CD18 staining, gold particles were seen on the plasma membrane and more rarely inside the cytoplasm of PMNL from each group but no decrease in this staining was noted in HIV PMNL. Incubation with f-MLP similarly increased the immunostaining of the PMNL in each group. In vitro ROI production was significantly depressed for HIV PMNL compared with control PMNL. Some ultrastructural abnormalities observed in this study could support the possibility that one of the mechanisms underlying the qualitative functional defects of PMNL from HIV-infected patients may be related to some cytopathic effect.

Impairment of HIV polymorphonuclear leukocyte transmigration across T84 cell monolayers: an alternative mechanisms for increased intestinal bacterial infections in AIDS?

Our objective was to study the influence of HIV infection of polymorphonuclear leukocytes (PMN) on transepithelial migration. To date, reports of functional PMN chemotaxis in AIDS are contradictory. This is the first attempt to assess this function via an in vitro model allowing transmigration of neutrophils through an intestinal epithelial barrier. PMN were isolated from 45 HIV-infected patients and 45 healthy volunteers. PMN transmigration across T84 epithelial cells was initiated by applying either various concentrations of formyl-met-leu-phe peptide (f-MLP) or interleukin-8 and assayed by quantification of myeloperoxidase activity. CD11b, CD18, and CD47 expression on PMN was compared before and after transepithelial migration by flow cytometry analysis. CD11b expression was studied by electron microscopy. Apoptosis of transmigrated HIV PMN and control PMN was investigated by morphology and DNA fragmentation characterization. Compared to control PMN, HIV PMN exhibited a decrease in transepithelial migration that directly correlated with CD4+ counts. Basal and transepithelial migration-mediated expression of CD11b, CD18, and CD47 were unmodified in HIV PMN compared to control PMN. Electron microscopy labeling confirmed no difference in CD11b expression on HIV and control PMN. The index of apoptosis in transmigrated HIV PMN and control PMN was identical. These data provide evidence of a defect in the f-MLP-induced chemotaxis of PMN from HIV-infected patients across an intestinal epithelial barrier. This defective migration is not due to a quantitative modification of CD11b, CD18 and CD47 on HIV PMN suggesting a more subtle alteration. The impairment in the transmigration function may contribute in vivo to an increased susceptibility to intestinal bacterial infection in HIV-infected patients.

Autopsy findings in the acquired immunodeficiency syndrome (AIDS). A report of 395 cases from the south of France.

Necropsy findings in 395 adult patients with the acquired immunodeficiency syndrome (AIDS) who died in Nice, France, between March 1983 and May 1996 were compared retrospectively with antemortem diagnoses, risk factors and number of positive T CD4 lymphocytes at the time of death. Special emphasis on bacterial infections was made in this study. Lesions observed from 1983 through 1989 and from 1990 through 1996 were compared. We assessed the role of organ lesions in the immediate cause of death. The organ system distribution of major opportunistic infections and neoplasms was similar throughout the years of the study. The most common diagnostic disease entities in all organ sites were cytomegalovirus infection, toxoplasmosis and candidiasis. Toxoplasmosis was more common in the intravenous drug abuser group. Bacterial infections were frequent and contributed to the mortality and morbidity of all risk factor groups. Kaposi' sarcoma continued to occur more frequently in the homosexual population. Cytomegalovirus infection remained one of the most common causes of death from 1983 to 1996. Mortality from fungal and bacterial infections, and mycobacteriosis increased in frequency during the course of this study whereas deaths from pneumocystosis declined. The death rate from malignant lymphoma and carcinoma increased after 1989. The clinical cause of death concurred with the pathological cause in 55% of the cases. Lung was the most frequent organ involved followed by the central nervous system the gastrointestinal tract and the heart.

[Epithelial tumors with thymus differentiation of the thyroid gland and the neck]. / Les tumeurs épithéliales à différenciation thymique de la glande thyroïde et du cou.

Epithelial tumors with thymus-like differentiation occurring in the thyroid gland and the neck, delineate four entities with distinct histological features and different behaviour. The spindle epithelial tumors with thymus-like differentiation are potentially malignant tumors occurring in the thyroid gland of young patients. They are highly cellular with pattern of spindle cells and tubulopapillary formations and mucinous glands. Carcinomas showing thymus-like differentiation of the thyroid gland are histologically identical to some thymic carcinomas. The ectopic hamartomatous thymoma is strictly benign and occurs in the soft tissues of the lower neck. It is characterized by spindle and solid or cystic islands of epithelial cells associated with adipose cells. The ectopic cervical thymoma is usually benign and histologically similar to mediastinal thymomas. All these tumors are particularly rare and arise from ectopic thymus or remnants of branchial pouch. The differential diagnoses of these tumors can be difficult and include some other proliferations occurring in the neck.

[Pulmonary lymphangioleiomyomatosis. Immunohistochemical and ultrastructural study of two cases]. / La lymphangioléiomyomatose pulmonaire. Etude immunohistochimique et ultrastructurale de deux observations.

The authors report two cases of pulmonary lymphangioleiomyomatosis which were diagnosed by surgical biopsies. Immunohistochemical study showed positive staining of the smooth muscle cells using antibodies directed against smooth muscle actin, specific muscle actin, HMB45 and vimentin. Ultrastructural study showed some smooth muscle differentiation features, with numerous myofilaments and some dense bodies near the plasma membrane. In one case, the patient was treated by a double-lung transplantation. LAM is a non-familial disease occurring exclusively in females. The etiology is unknown. This disease can be complicated by chronic respiratory failure. Extrapulmonary sites are not rare, particularly in the uterus. Anti-estrogen treatment can slow the course of the disease. Lung transplantation is actually the only effective treatment at the present time therapy. The differential diagnosis of this disease is discussed.

[Cutaneous malacoplakia. An immunohistochemical and ultrastructural case study]. / La malacoplakie cutanée. Etude immunohistochimique et ultrastructurale d'une observation.

The authors report a case of a 70 year-old man with a past of myelodysplasia and presenting a voluminous lesion of the thigh corresponding to a cutaneous malacoplakia. Histologic study showed a dermo-hypoderma granuloma with numerous Von Hansemann cells containing some Michaelis-Gutmann bodies. Immunohistochemical study showed a positivity of these cells with the antibodies against CD68 (KP1, Mac 387, PGM1), the lysozyme and the alpha-chemotrypsine. Ultrastructural study confirmed the histiocytic origin of this infiltration by showing some regular and voluminous inclusions with a clear center and a peripheral and dense ring, and also some bacteria measuring 3 to 5 microns. Bacteriological study isolated an Escherichia coli. The evolution was favourable after surgical excision and antibiotherapy. Cutaneous malacoplakia is a very rare disease, usually with a perineal localization, and occurring in immunodeficient host. Michaelis-Gutmann bodies are sometimes difficult to identify by light microscopy underlying the rule of the immunohistochemical and the ultrastructural studies to perform the diagnosis.

[Kimura's disease of the lymph node. Histology, immunohistochemistry, and differential diagnosis]. / La maladie de Kimura ganglionnaire. Histologie, immunohistochimie, et diagnostic différentiel.

Kimura's disease, a chronic inflammatory condition of unknown cause, occurs predominantly in young Asian adult men. The disease involves subcutaneous tissues and lymph nodes in the head and neck region. We report a new case occurring in a young woman. The diagnosis was made late on a retroauricular lymph node examination. Immunohistochemical study showed that B lymphoid area remained, located in the germinal center showing some fibrosis involvement, and in the subcortex. T lymphoid zones were observed in the paracortex. Strong IgE positivity was noted in germinal centers. Vessels were positive with CD31, CD34, factor VIII and smooth muscle actin antibodies. Warthin-Finkeldey cells were negative for lymphoid and macrophagic markers used in this study. Differential diagnosis is discussed.

[Placenta toxoplasmosis in the course of AIDS. Immunohistochemical and ultrastructural study of a case]. / Toxoplasmose placentaire au cours du SIDA. Etude immunohistochimique et ultrastructurale d'une observation.

Histological lesions occurring in the placenta of human immunodeficiency virus positive women are rare and non specific and opportunistic infections are exceptional. We report the case of a female intravenous drug abuser with AIDS, who had an abortion associated with fever. Histological, immunohistochemical and ultrastructural studies of the placenta allowed the diagnosis of toxoplasmic infection. In comparison of the high frequency of toxoplasmic lesions seen in different organs, we did not find any case in the literature of placenta toxoplasmosis in AIDS.