Hepatobiliary tuberculosis

Tuberculosis is known to involve the liver in different ways. The term hepatobiliary tuberculosis refers to the localized form of hepatic tuberculosis as a distinct clinical entity, with signs and symptoms related to the hepatobiliary tract. Its clinical features and the different diagnostic aids used in its diagnosis are reviewed. Plain abdominal radiographs showing diffuse hepatic calcifications seen in approximately 50% of cases are almost diagnostic for hepatobiliary tuberculosis. Liver biopsies obtained either by ultrasound, computed tomography or laparoscopy, showing caseating granuloma usually establish the diagnosis. In the absence of caseation necrosis, a positive acid-fast bacillus (AFB) or culture for Mycobacterium tuberculosis is needed to establish the diagnosis. A polymerase chain reaction assay for the identification of Mycobacterium tuberculosis in liver biopsy specimens is a new development. Treatment is similar to that used for pulmonary tuberculosis. Quadruple therapy (using four anti-tuberculosis drugs) is recommended, generally for 1 year. For patients with obstructive jaundice, in addition to anti-tuberculous treatment, biliary decompression should be performed either by stent insertion during endoscopic retrograde cholangiopancreatology, by percutaneous transhepatic biliary drainage or by surgical decompression whenever feasible.

A possible role of multidrug resistance-associated protein (MRP) in basic fibroblast growth factor secretion by AIDS-associated Kaposi's sarcoma cells: a survival molecule?

Kaposi's sarcoma (KS) is considered a disorder of cytokines. Basic fibroblast growth factor (bFGF) is produced by AIDS-associated KS (AIDS-KS) cells and supports their growth in an autocrine and paracrine manner. bFGF lacks a signal sequence; therefore, its mechanism of secretion is unclear. In this study, we investigate the role of two important members of ATP-binding cassette transport proteins, the P-glycoprotein (P-gp) and multidrug resistance-associated protein (MRP), in the secretion of bFGF from AIDS-KS cells. Expression of P-gp and MRP was examined at both the protein and the mRNA levels by flow cytometry and RT-PCR respectively. Intracellular and secreted bFGF was measured by ELISA. AIDS-KS cells expressed MRP at both the mRNA and the protein levels; however, no P-gp expression was detected at either the mRNA or the protein level. Probenecid, a putative inhibitor of MRP efflux function, in a concentration-dependent manner, inhibited bFGF secretion, with a concomitant increase in intracellular bFGF, demonstrating that probenecid blocks bFGF secretion without inhibiting its synthesis. In addition, probenecid induced apoptosis in AIDS-KS cells. AIDS-KS cells expressed fas, bcl-2, and bcl-xL genes but lacked fasL and bax gene expression. These data suggest that bFGF is secreted from AIDS-KS cells via a probencid-sensitive transporter, most likely in MRP. Furthermore, probenecid appears to induce apoptosis in AIDS-KS cells by depriving them of the growth promoting activity of bFGF. These data suggest that MRP may play a role as a survival molecule in AIDS-KS cells.

The podiatric examination

With the evolution of the AIDS epidemic into a relatively chronic disease, practitioners will continue to see an increase in the number of patients infected with HIV for the diagnosis and management of podiatric pathology. A thorough history and physical examination, taken with a complete knowledge base of HIV implications, will enhance the ability to form the strategies required to treat the manifestations of this disease and to request appropriate referrals. Laboratory studies and other diagnostic techniques have been developed and increased in specificity to allow for earlier and more precise identification of the presenting pathology. A continuously expanding choice of medications is available for treatment. The clinical presentations of HIV infection in the foot involve nearly all organ systems. This article reviews the podiatric role as part of the medical team in the diagnosis and treatment of patients infected with HIV.

Association of cutaneous and oral diseases in HIV-infected men

OBJECTIVES

Mucocutaneous diseases are common in patients infected with human immunodeficiency virus (HIV). To identify cutaneous diseases for which HIV-infected people are at high risk, we sought those that are strongly associated with specific HIV-related oral lesions and with progression of HIV disease.

DESIGN

A cross-sectional study of HIV-positive outpatients referred to a university stomatology clinic for diagnosis and treatment of oral diseases. Each subject underwent both complete oral and cutaneous examinations.

RESULTS

Among 55 men, with a median age of 41 years and a median CD4 cell count of 125/microliter (range 0-950/microliter), 93% had active oral diseases or conditions, including candidiasis, hairy leukoplakia, ulcers, Kaposi's sarcoma (KS), and xerostomia, and 95% had skin conditions, including onychomycosis, dermatophytosis, seborrheic dermatitis, KS, folliculitis, xerosis, and molluscum contagiosum. Seborrheic dermatitis, xerosis, skin KS, and molluscum contagiosum were associated with oral HIV-sentinel lesions (oral candidiasis, hairy leukoplakia, and KS), with low CD4 cell counts, and with AIDS.

CONCLUSION

Our results suggest that xerosis and seborrheic dermatitis may be early harbingers of HIV disease progression. Their roles as predictors warrant further study, based on their associations with low CD4 cell counts and AIDS and strong co-prevalence with one of the most common HIV-related oral lesions, oral candidiasis.

Psychosocial aspects of seropositive HIV patients

Acquired immunodeficiency syndrome, has become a serious global health problem with an enormous biomedical impact and diverse psychological and clinical manifestation. A study was conducted wherein seropositive HIV patients admitted in a medical ward were assessed for demographic profile, presenting physical illness, mode of contacting the infection, psychiatric morbidity and associated psychosocial factors. The results revealed male preponderance and heterosexual unprotected exposure as the common mode of contacting the illness. It was observed that majority of the patients presented with tuberculosis. Psychiatric assessment revealed a high rate of depressive and anxiety syndromes. Thus it was concluded that the HIV-infected population has a higher prevalence of psychiatric disorders as compared to the general population. The reason for this includes psychological, biological and social factors.

[Coinfection of hepatitis B and C in HIV-infected patients]

There is only limited information on the prevalence and influence of coinfection with either hepatitis B or C on the clinical course in patients infected with the human immunodeficiency virus (HIV). Samples of 232 HIV infected patients were investigated for markers of HBV and HCV infection (HBsAg, HBeAg, Anti-HBs, anti-HBc, anti-HCV, HCV-RNA). 60/232 patients (23%) were anti-HCV positive. 78% of these sera were positive for HCV-RNA. 22/232 patients (9%) suffered from chronic HBV-infection (HBsAg positive), 18/22 (82%) of these sera had detectable HBeAg. Presence of HCV-RNA, HBeAg was related to the degree of immunodeficiency. In patients with AIDS coinfection with HBV or HCV was associated with a reduced survival compared to controls (HBV: 212 days, 95% CI, 106 to 317; HCV: 267, 95% CI, 112 to 396; controls: 439 days, 95% CI, 364 to 513). Coinfection of HIV and HBV or HCV is frequently observed. Our results suggest that in HIV-infected patients with AIDS coinfection with either HBV or HCV was associated with a reduced survival rate.

[Tuberculosis in HIV-positive and HIV-negative drug users in Amsterdam]

OBJECTIVE

To determine and to compare the incidences of active tuberculosis in HIV positive and HIV negative drug users and to describe the main characteristics of the tuberculosis cases.

DESIGN

Prospective.

SETTING

Municipal Health Service, Amsterdam, the Netherlands.

METHOD

Data of the ongoing cohort study of HIV infection in Amsterdam drug users, including HIV serostatus and CD4 cell counts, from 1986 until 1996 were completed with data from the tuberculosis registration of the tuberculosis department of the Amsterdam Municipal Health Service and analysed statistically.

RESULTS

Of 872 participants 24 persons developed culture confirmed tuberculosis during a total follow-up period of 4000 person years (py) (0.6 per 100 py). Nineteen persons were HIV positive (1.54 per 100 py) and 5 HIV negative (0.18 per 100 py). Multivariately, HIV infection and higher age increased the risk of tuberculosis substantially (relative risks 12.9; 95% confidence interval (CI): 3.4-48.8 and 6.8: 95% CI: 1.3-35.0 respectively). Thirteen of 22 pulmonary tuberculosis cases (59%) were detected by half-yearly X-ray screening of the chest. Tuberculosis occurred relatively early in the course of HIV infection at a mean CD4 cell number of 390/microliter. All but one patient completed the tuberculosis treatment.

CONCLUSION

HIV infection increases the risk of active tuberculosis in Amsterdam drug users 13-fold. The incidence of tuberculosis in HIV negative drug users in 6 times higher than that in the overall Amsterdam population. Periodic chest X-ray screening contributes substantially to case-finding of active tuberculosis in Amsterdam drug users.

Pneumonia in AIDS patients in the critical care unit

Despite advances in prophylaxis and the reduction of mortality and morbidity resulting from highly active antiretroviral therapy, neumocystis pneumonia remains a common problem in HIV-infected patients. There are many possible causes for the continued prevalence of this condition. This article examines the characteristics, and some of the complex causes of P. carinii pneumonia in AIDS patients.

Surgical infections in immunocompromised patients--prevention and treatment

The care of immunocompromised patients is a challenge to all physicians. The variety of opportunistic infections that can develop in these patients underscores the importance of the immune response. The key to success in the prevention and management of infections in these patients lies in knowing what kind of infections to expect and instituting empirical treatment even before a specific diagnosis is made. With the advent of better preventive strategies, the use of prophylactic and preemptive therapies, and the introduction of new immunomodulators, successful outcomes in these interesting and challenging patients may be more easy to achieve in the future.

The placental barrier to maternal HIV infection

Infection with HIV destroys the immune system and causes acquired immunodeficiency syndrome (AIDS). Death results from common bacterial and opportunistic infections that are rare in persons with a healthy immune system. HIV infection frequently is a fatal sexually transmitted disease that can also be transmitted from an infected mother to her offspring.

Natural history of HIV infection in women

Women represent the fastest growing group of adults with AIDS, and poor African-American and Latina women are disproportionately affected. There are differences in the clinical presentation of HIV symptoms in women. Although disease progression seems to be similar for women and men, women with HIV infection seem to have a higher mortality rate than men. Gender, racial, and class differences in access to care may account for this. Phases of the natural history of HIV infection in women are reviewed and include prevention opportunities, acute infection, viral and immunologic parameters of pathogenesis, therapeutic plans, and terminal care.

Does methotrexate increase the risk of infection or malignancy?

Most patients do not exhibit overt signs of immunosuppression. Studies cited in this article support a modest increase in the rate of bacterial respiratory and skin infections. Opportunistic infections occur rarely, however, and may be life threatening. The case for MTX carcinogenicity is less clear. The risk for malignancy other than lymphoproliferative disorders does not seem to be elevated, although multiple sporadic malignancies have been reported in treated patients. MTX is a superb agent for the therapy of a large group of immune-mediated diseases. Although an increased risk for infection and possible malignancy exists, the risk is small compared with the potential clinical benefit.

The demography, clinical manifestations and natural history of human immunodeficiency virus (HIV) infection in an older population in Singapore

In this retrospective study, we report 43 cases (41 males and 2 females) of human immunodeficiency virus (HIV) infection in the Singapore population aged 50 years and above at first presentation. We found an increasing proportion of these older individuals among our HIV-seropositive patients; from 4.8% in 1991 to 16.7% by mid-1996. The mean age at presentation was 59.2 years (range 50 to 75 years). They were mainly heterosexuals (93%) and the majority (79.1%) were previously or currently married. Thirty-six (83.7%) patients had multiple sexual exposures to commercial sex workers. Nearly all had acquired the infection through the sexual route. The majority (76.7%) were symptomatic at presentation. Common clinical presentations were weight loss (72%), respiratory symptoms (60%) and oral candidiasis (56%). More than half (58.1%) of the patients had acquired immunodeficiency virus (AIDS) at the time of first presentation with a low median CD4 count of 17 cells/mm3. Pneumocystis carinii pneumonia and tuberculosis were the common AIDS-defining diseases. Survival in patients presenting with AIDS (median survival 3 months) is poorer compared to younger HIV-seropositive patients (< 50 years; median survival 1 year). No increase in age-related infection or malignancy was seen. Common causes of death were pneumonia and septicaemia. Physicians should consider HIV infection in older patients particularly when he/she presents with unexplained weight loss, respiratory symptoms and oral candidiasis. A history of high-risk sexual behaviour must be sought in all patients, including the elderly.

Aetiology of Kaposi's sarcoma: current understanding and implications for therapy

Kaposi's sarcoma is an angiogenic neoplasm composed of endothelial and spindle cells. The enormous increase in Kaposi's sarcoma with HIV infection, and recent discovery that a new human herpesvirus (Kaposi's sarcoma-associated herpesvirus, also called human herpesvirus 8) is present in this tumor, has activated intense interest in the aetiology, epidemiology and pathogenesis of this disease. Today, Kaposi's sarcoma is one of the most frequent neoplasms in men under 50 years old in the USA, and in some African countries it is the most common tumour overall.

Cryptococcus neoformans infection in mice previously infected with LP-BM5 MuLV, the agent of murine AIDS (MAIDS)

We studied susceptibility to experimental systemic cryptococcosis in mice previously infected with the retroviral complex LP-BM5 (responsible for murine AIDS). LP-BM5 was inoculated to C57B1/6 mice by intravenous (i.v.) injection 8 weeks before an i.v. challenge with 4 x 10(3) CFU of Cryptococcus neoformans. Uninfected and singly infected mice were used as controls. LP-BM5 infection did not result in a significant increase in fungal burdens in the lungs or brains of co-infected animals compared to mice infected with C. neoformans alone. However, mortality was enhanced in the co-infected animals. The kinetics of splenocyte subsets differed in co-infected mice and LP-BM5-infected mice; the increase in CD4+, CD8+ and Ly5+ cells was only moderate in the former. Cytokine production by concanavalin A (Con A)-stimulated splenocytes from co-infected mice showed a marked decrease in the Th1 response (IFN-gamma, IL-2) and an increase in the Th2 response (IL-4, IL-10). Furthermore, cryptococcosis altered the course of MAIDS, inhibiting splenomegaly. This effect was not related to a decrease in ecotropic virus titres in the spleen or to improved in vitro responsiveness of spleen cells to Con A. The marked decrease in IFN-gamma production in co-infected animals could partly explain the inhibition of LP-BM5-induced splenomegaly. This model of murine retroviral infection does not seem to be suitable for studying cryptococcosis in immunosuppressed animals, but remains valuable for investigating in vivo interactions between two pathogens.