Kaposi's sarcoma of the gastrointestinal tract: report of two cases and review of the literature

Involvement of Kaposi's sarcoma in the gastrointestinal tract is common in AIDS patients and can also occur in non-AIDS patients. However, the disease is usually asymptomatic and, due to tumor growth primarily in the submucosa, biopsy diagnosis is possible in less than 25%. In the present study, we describe two cases of Kaposi's sarcoma that were first diagnosed in the gastrointestinal tract of a 74-year-old patient who presented to the clinic with nausea and vomiting. On esophagogastroduodenoscopy, a lesion 0.7 cm in size was found. Histology revealed a Kaposi's sarcoma of the stomach with existing HHV8 infection, and there were negative tests for HIV. The second case is a 39-year-old patient with multiple lesions in the stomach and in the small and large intestine. The histology verified multiple Kaposi's sarcomas that were HHV 8-positive. Afterwards, the diagnosis of an HIV infection was made. Primary diagnosis of Kaposi's sarcoma of the gastrointestinal tract in HIV-negative patients is certainly rare and more frequently made in HIV patients. Nevertheless, Kaposi's sarcoma must always be considered in lesions of the gastrointestinal tract or in gastrointestinal bleeding and should lead to further elucidation of the causes.     

HIV/AIDS患者CD28在外周血CD4+、CD8+ T细胞上的表达变化

目的　研究国内HIV AIDS患者CD2 8在外周血CD4 + 、CD8+ T淋巴细胞上表达的变化 ,并探讨这些变化的临床意义。方法　用流式细胞仪检测 5 1例正常对照、14例HIV感染者和 36例AIDS患者的外周血CD4 + 、CD8+ T淋巴细胞表面的CD2 8分子的表达 ,用bDNA法检测 11例HIV感染者和 18例AIDS患者的血浆病毒载量。结果　CD4 + CD2 8+ T细胞的绝对计数与百分比、CD8+ CD2 8+T细胞的百分比均显示为正常对照组 >HIV感染组 >AIDS组 ;而CD8+ CD2 8+ T细胞的绝对计数显示HIV感染组和对照组显著大于AIDS组 ,HIV感染组与对照组间差异无显著性。CD4 + 、CD2 8+ CD4 + T淋巴细胞计数与血浆病毒载量显著负相关。结论　HIV AIDS患者外周血CD2 8在CD4 + 、CD8+ T淋巴细胞上表达随着病情进展而降低 ,反映了细胞免疫功能随着疾病进展损害逐渐加重 ,是判断病情进展的指标。     

Fas (CD95) expression on CD4+ T cells from HIV-infected patients increases with disease progression

Active T cell suicide (apoptosis) is supposed to be involved in the CD4⁺ T cell depletion in the course of HIV infection. We investigated the expression of the apoptosis-related antigen Fas on CD4⁺ T cells from 25 HIV-positive individuals (CDC I-III) and 8 HIV-negative controls by two-colour flowcytometry. In addition, we evaluated: total CD4 count, HIV p24 antigen concentration in serum after immune complex dissociation, and clinical course of infection in HIV-positive individuals. We found a significant increase in mean Fas expression on CD4⁺ T cells from HIV-positive individuals compared to HIV-negative individuals (85.84±14.92% vs. 64.28±7.59%, P<0.001). Within the HIV-positive group the increase in Fas expression was correlated with the decline in CD4 count (r=–0.76, P<0.001), p24 antigen concentration in serum after immune complex dissociation (r=0.67, P<0.001), and CDC stage (r=0.73, P<0.001). The upregulation of Fas antigen on CD4 cells is associated with CD4 depletion and other virological and clinical marker of disease progression in HIV infection.Abbreviations AIDS Acquired immunodeficiency syndrome - CDC Center of disease control - CTL Cytotoxic T lymphocyte - FasL Fas ligand - HIV Human immunodeficiency virus - MFI Mean fluorescence intensity     

存放温度及时间对于HIV/AIDS患者外周血CD4+、CD8+细胞测定结果的影响

目的　研究HIV AIDS患者外周血CD4 、CD8 淋巴细胞数在不同条件下 (时间、温度和处理过程 )的变化。方法　选取HIV AIDS患者 34例 ,用流式细胞术检测在 4℃条件下放置不同时间(2、2 4、4 8、72h)的外周血CD4 、CD8 细胞数的变化 ,对经过处理的外周血 (处理过的血样 )CD4 、CD8 细胞数的变化进行比较 ;对室温条件下放置不同时间 (2、2 4、4 8、72h)处理过的血样CD4 、CD8 细胞数的变化进行比较。结果　在 4℃时 ,全血放置 2、2 4、4 8、72h的CD4 细胞计数差异无显著意义(P >0 0 5 ) ,而CD8 细胞数放置 72h时则差异有显著意义 (P <0 0 5 ) ;处理过的样品放置 72hCD4 细胞计数差异才有显著意义 (P <0 0 5 ) ,而CD8 细胞数在 2 4h时差异就有显著意义 (P <0 0 5 )。在室温时 ,处理过血样放置 2、2 4、4 8、72h的CD4 细胞计数差异无显著意义 (P >0 0 5 ) ,而CD8 细胞数在 4 8h则差异有显著意义 (P <0 0 5 )。结论　抗凝全血在 4℃放置 4 8h ,检测CD4 、CD8 淋巴细胞数 ,结果是可靠的。处理过血样在室温放置 2 4h ,检测CD4 、CD8 淋巴细胞数 ,结果是可靠的。 2 4～4 8h虽然CD4 淋巴细胞没有变化 ,但CD8 淋巴细胞却发生明显的变化 ,两者比例必然发生变化。     

Antibody-dependent cellular cytotoxicity (ADCC)-mediated destruction of human immunodeficiency virus (HIV)-coated CD4+ T lymphocytes by acquired immunodeficiency syndrome (AIDS) effector cells

The acquired immunodeficiency syndrome (AIDS) is defined in clinical terms by the development of Kaposi's sarcoma and/or severe opportunistic infections in persons without predisposing conditions. A hallmark of the syndrome has been a decrease in the number of CD4⁺ T helper cells. The reduction in the frequency of the CD4⁺ lymphocytes has been postulated to be primarily the result of human immunodeficiency virus (HIV) tropism and cytophathogenicity for the T-cell subset. Yet only a small percentage of cells is actually infected with HIV. Recently, we provided evidence indicating that AIDS patients' natural killer cells can mediate normal levels of antibody-dependent cellular cytotoxicity (ADCC) despite exhibiting a defect in natural killer (NK) effector function (J Immunol 139:55, 1987). This finding prompted us to investigate whether AIDS patients' effector cells could mediate ADCC against circulating CD4⁺ T cells infected with or expressing HIV antigen. The findings reported herein demonstrate that AIDS effector cells can mediate lysis of CEM (CD4⁺ T-cell line) coated with HIV protein in the presence of HIV-specific antibody. Lysis was specific, as non-HIV-coated CEM or the addition of HIV-negative serum resulted in no lysis. We then examined HIV-coated peripheral blood-derived CD4⁺ T lymphocytes as targets in ADCC. We demonstrate that in the presence of HIV-specific antibody, HIV-coated CD4⁺ T lymphocytes serve as targets for ADCC by AIDS effector cells. The lytic activity obtained with AIDS effector cells was comparable to that obtained with normal effector cells. These results demonstrate that AIDS effector cells can mediate ADCC against HIV-coated CD4⁺ T lymphocytes and suggest that ADCC may play a rolein vivo in the pathogenesis of AIDS.     

HIV病发病学新概念：肠淋巴组织主要病灶论

艾滋病 (acquiredimmunodeficiencysyndrome ,AIDS)无疑是人类空前严重的疾病 ,这不仅仅因为它是一种流行范围最广的传染病 ,而且它还是一种死亡率几乎高达 10 0 %的疾病。人免疫缺陷病毒病(humanimmunodeficiencyvirusdisease ,HIVdisease)指从HIV感染到AIDS发病整个病程 ,HIV     

Influence of HIV-1 and/or HIV-2 infection and CD4 count on cervical HPV DNA detection in women from Senegal,West Africa

BackgroundHIV infection is associated with greater risk of precancerous lesions and cervical cancer in women. However, several factors remain unclarified regarding the association between HIV infection and HPV detection, especially among those with HIV type 2 versus type 1 infection and severely immunocompromised persons.ObjectivesTo evaluate HPV overall and type-specific detection among HIV-infected and uninfected women in Senegal.Study designDetection of HPV DNA for 38 genotypes in cervical swabs using PCR-based methods was evaluated in HIV-positive (n = 467) and HIV-negative (n = 2139) women participating in studies in Senegal. Among HIV-1 and/or HIV-2 positive women, CD4 counts were assessed. Adjusted multivariable prevalence ratios (PR) were calculated.ResultsThe prevalence of any HPV DNA and multiple HPV types was greater among HIV-infected individuals (78.2% and 62.3%, respectively) compared with HIV-negative women (27.1% and 11.6%). This trend was also seen for HPV types 16 and 18 (13.1% and 10.9%) compared to HIV-negative women (2.2% and 1.7%). HIV-infected women with CD4 cell counts less than 200 cells/μl had a higher likelihood of any HPV detection (PR_a 1.30; 95% CI 1.07–1.59), multiple HPV types (PR_a 1.52; 95% CI 1.14–2.01), and HPV-16 (PR_a 9.00; 95% CI 1.66–48.67), but not HPV-18 (PR_a 1.20, 95% CI 0.45–3.24) compared to those with CD4 counts 500 cells/μl or above.ConclusionHIV-infected women, especially those most severely immunocompromised, are more likely to harbor HPV. Measures to prevent initial HPV infection and subsequent development of cervical cancer through focused screening efforts should be implemented in these high risk populations.     

Fine-needle aspiration cytology of lymphadenopathy in homosexual males

We report five patients who illustrate the usefulness of fine-needle aspiration cytology (FNAC) in the differential diagnosis of lymphadenopathy in homosexual males. This differential includes hyperplasia, disseminated Kaposi's sarcoma, mycobacterial infections, and non-Hodgkin's lymphoma.     

Effects of Talaromyces marneffei infection on mortality of HIV/AIDS patients in southern China: a retrospective cohort study

Objective

Talaromyces marneffei is an opportunistic infection with high morbidity among human immunodeficiency virus (HIV)/AIDS patients in Southeast Asia and southern China. Its effects on mortality in HIV/AIDS patients has not been clearly elucidated.

Increased expression of CD80, CD86 and CD70 on T cells from HIV-infected individuals upon activation in vitro: regulation by CD4+ T cells

T cells express CD28 and CD27 which transduce co-stimulatory signals after interaction with their ligands on antigen-presenting cells (APC). These ligands, CD80, CD86 and CD70, are also expressed to some extent on activated T cells. Here, we show that in human immunodeficiency virus (HIV)-infected individuals, CD28 and CD27 expression is decreased on CD8⁺ T cells. On the other hand, T cell stimulation in vitro induced high CD80, CD86 and CD70 expression on T cells from HIV-infected individuals. It appeared that an inverted CD4:CD8 T cell ratio could explain this enhanced expression of co-stimulatory ligands. Indeed, high expression levels of CD80, CD86 and CD70 were found on activated CD8⁺ T cells from HIV⁻ individuals cultured in the absence of CD4⁺ T cells. Addition of CD4⁺ T cells prevented this up-regulation. However, in HIV-infected individuals, addition of excess autologous or healthy control CD4⁺ T cells did not completely counteract up-regulation of co-stimulatory ligand expression on CD8⁺ T cells. Thus, to some extent, CD8⁺ T cells in HIV-infected individuals appeared to be refractory to CD4⁺ T cell-mediated regulation of ligand expression in vitro. Activated T cells from HIV-infected individuals and activated CD8⁺ T cells from healthy controls were able to act as accessory cells in CD3-induced T cell proliferation, which was dependent on cell-cell contact. Thus, we showed that T cells from HIV-infected individuals express enhanced levels of co-stimulatory ligands upon activation, which provides them with accessory cell properties. Enhanced stimulatory potential of these nonprofessional APC may contribute to persistently high levels of immune activation in HIV infection related to disease progression.     

Deletion of T lymphocytes in human CD4 transgenic mice induced by HIV-gp120 and gp120-specific antibodies from AIDS patients

CD4, a T cell receptor for major histocompatibility complex class II antigen, is a key regulator of immunological reactivities. When engaged together with the T cell antigen receptor, CD4 enhances immune reactions, whereas when ligated independently of the antigen receptor CD4 inhibits the activation of T cells or initiates their deletion. CD4 serves also as a receptor for the human immunodeficiency virus (HIV), which binds the receptor with high avidity through its envelope molecule, gp120. Studies in tissue culture have shown that its affinity to CD4 gives the virus opportunities to utilize CD4-mediated signaling and to manipulate immunocytes. We show here in human CD4 transgenic mice that appropriately cross-linked HIV envelope protein causes massive deletion of HIV-reactive T cells in vivo.     

Expression of CD8alpha identifies a distinct subset of effector memory CD4+ T lymphocytes

Circulating CD4+ CD8+ T lymphocytes have been described in the peripheral blood of humans and several animal species. However, the origin and functional properties of these cells remain poorly understood. In the present study, we evaluated the frequency, phenotype and function of peripheral CD4+ CD8+ T cells in rhesus macaques. Two distinct populations of CD4+ CD8+ T cells were identified: the dominant one was CD4hi CD8lo and expressed the CD8alphaalpha homodimer, while the minor population was CD4lo CD8hi and expressed the CD8alphabeta heterodimer. The majority of CD4hi CD8alphalo T cells exhibited an activated effector/memory phenotype (CCR5lo CD7- CD28- HLA-DR+) and expressed relatively high levels of granzyme B. Intracellular cytokine staining assays demonstrated that the frequency of cytomegalovirus-specific T cells was enriched five-fold in CD4hi CD8alphalo T cells compared to single-positive CD4+ T cells, whereas no consistent enrichment was observed for simian immunodeficiency virus (SIV)-specific T cells. Cross-sectional studies of SIV-infected animals demonstrated that the frequency of CD4hi CD8alphalo T cells was lower in wild-type SIV-infected animals compared to uninfected controls, although prospective studies of SIV-infected animals demonstrated depletion of CD4hi CD8alphalo lymphocytes only in a subset of animals. Taken together, these data suggest that CD4+ T cells expressing CD8alpha represent an effector/memory subset of CD4+ T cells and that this cell population can be depleted during the course of SIV infection.     

Pyogenic granuloma of the large intestine: Case report and review of reported cases in the adult

Pyogenic granuloma (PG) is a polypoid lobular capillary hemangioma rarely described in the large bowel. We describe the case of a 72-year-old man with recent weight loss, anemia, and change in bowel habit. A 3 cm × 2 cm polypoid lesion in the right flexure of the colon was observed and treated with extended right hemicolectomy. A review of the English-language literature on PG of the large bowel in adults yielded eight previously reported cases. The age of the patients ranged from 26 to 80 years with a mean of 54.8 years. The lesions were all solitary, except one case of multiple lesions in the colon. Another case was associated with satellite lesions. Seven cases were located in the colon and two in the rectum. The mean maximum diameter of the lesions was 1.6 cm (range 0.5–3 cm). Colorectal bleeding was the most common clinical symptom. Due to its unusual appearance, PG can be misdiagnosed and mistreated as colon carcinoma with extensive surgery. Polypectomy or endoscopy mucosal resection is the optimal treatment. In large or deep lesions, a surgical excision may be necessary. Pathologists should be familiar with this condition so as to avoid overdiagnosis as a malignant vascular tumor.     

Ultrastructural characterization of human herpesvirus 8 (Kaposi's sarcoma- associated herpesvirus) in Kaposi's sarcoma lesions: electron microscopy permits distinction from cytomegalovirus (CMV)

Kaposi's sarcoma (KS) has been shown by molecular techniques to be associated with infection with human herpesvirus 8 (HHV8/KSHV), but specific ultrastructural characterization of the virus has been impaired by the frequent presence in these lesions of other herpesviruses, particularly cytomegalovirus (CMV). Since the ultrastructural appearance of HHV8/KSHV has been studied in the cell line KS-1 uninfected with other viruses including CMV, it was possible to undertake a comparative study of CMV and HHV8/KSHV in KS lesions. HHV8/KSHV was sparsely present and lytic infection was restricted to endothelial cells. The following specific ultrastructural features allowed distinction between HHV8/KSHV and CMV: the viral particles were more delicate and less numerous in cases of HHV8/KSHV infection; the viral tegument was more electron-dense in CMV than in HHV8/KSHV; dense bodies characteristic of CMV were absent in HHV/KSHV; complete CMV viral particles were more variable in size and generally larger (150–200 nm) than HHV8/KSHV (120–150 nm); and finally, the viral envelope was more pleomorphic in CMV than in KSHV/HHV8. Similarities between CMV and HHV8/KSHV included the basic structure of the nucleocapsids and the presence of capsids lacking central DNA cores (so-called non-infectious enveloped particles). These observations show that electron microscopy can be used to identify HHV8/KSHV and confirm the relationship between HHV8/KSHV and KS. © 1997 John Wiley & Sons, Ltd.     

In vitro separation and expansion of CD4 lymphocytes from HIV-infected individuals without activation of HIV infection

In order to offer a gene therapy-based treatment against AIDS, it is likely to be necessary to harvest and culture CD4 cells from HIV-positive patients without activating the HIV infection. We have used a magnetic cell sorting (MACS) system to enrich CD4 cells. Using positive selection, CD4 cells from a total of 14 patients were enriched from a mean percentage of CD4 cells in PBMC of 18% to 91% CD4 cells in the enriched cell fraction. Furthermore, we found that this separation did not lead to an increase in viral load. The MACS performed equally well on cells from HIV-positive patients and HIV-negative donors. CD4 cells from HIV-positive patients were readily expanded with PHA; 19-fold by day 10, 50-fold by day 20, and 156-fold by day 25. However, CD4 cells from HIV-positive patients grew at a slower rate than CD4 cells from HIV-negative donors. The expanded CD4 cells showed a high degree of CD4 expression and no loss of polyclonality. Only in two of six cultures were we able to detect HIV-antigen production, and using an LTR-PCR and an RT assay, we did not find activation of the HIV infection during the culture period. Thus, the method described separates and expands CD4 cells from HIV-positive patients without activation of the HIV infection.     

Induction of CD95 ligand expression on T lymphocytes and B lymphocytes and its contribution to apoptosis of CD95-up-regulated CD4+ T lymphocytes in macaques by infection with a pathogenic simian/human immunodeficiency virus

Using an established SIV/HIV-C2/1-infected cynomolgus monkey model displaying stable CD4+ T cell depletion, the kinetics of apoptosis and the levels of expression of CD95 membrane-associated CD95L on lymphocytes were investigated to test the involvement of the CD95/CD95L system in CD4+ T lymphocyte loss in vivo. Rapid depletion of CD4+ T cells occurred up to 2 weeks after infection, with chronic CD4+ T lymphopenia thereafter. During the initial CD4+ T cell loss, which was accompanied by viraemia, about 90% of the peripheral CD4+ T cell subset underwent spontaneous apoptotic cell death during 24 h of culture. Increased expression of CD95 was observed on both CD4+ and CD8+ T cell subsets, with CD95 expression on CD8+ cells declining rapidly, but high CD95 expression being maintained on CD4+ cells. Since CD95L was expressed on CD8+ T cells, B cells and to a lesser extent on CD4+ T cells, this suggests that CD95-mediated apoptosis might be controlled in an autocrine/paracrine fashion.     

Patterns of antibody reactivity to selected human immunodeficiency virus type 1 (HIV-1) gp160 epitopes in infected individuals grouped according to CD4+ cell levels

We examined sera from 160 HIV-infected individuals for antibodies reactive to HIV-1 gp160 epitopes defined by seven synthetic peptides. Seropositive individuals were placed into three groups based upon levels of circulating CD4+ cells. These groups consisted of individuals with (1) more than 400 CD4+ cells, (2) 200–400 CD4+ cells, and (3) fewer than 200 CD4+ cells/mm³. The percentage of sera containing antibodies reactive with two immunodominant gp160 epitopes (a.a. 304–321 and 600–611) was unchanged between groups, regardless of CD4 cell numbers. The percentage of sera containing antibodies reactive with weakly immunogenic gp160 epitopes, such as those defined by peptides 425–448 and 846–860, declined in the groups as CD4 values decreased. Our results suggest that the patterns of antibody reactivity to gp160 epitopes change as CD4 levels decline. A narrowing of the humoral immune response to epitopes on the envelope of HIV-1 appears to occur with disease progression.