Visceral leishmaniasis in patients infected with human immunodeficiency virus (HIV)

Ethiopian visceral leishmaniasis patients co-infected with human immunodeficiency virus

This communication reports 7 Ethiopian visceral leishmaniasis (VL) patients co-infected with human immunodeficiency virus (HIV). The clinical and laboratory findings in 6 patients did not differ from classical VL. All patients had highly elevated anti-leishmanial antibody titres, determined by immunoglobulin G-based enzyme-linked immunosorbent assay; they most probably acquired the Leishmania infection before HIV. Amastigotes were identified in the splenic aspirates of 6 patients and in the lymph node aspirate of the 2 patients whose lymph nodes were examined. The CD4:CD8 lymphocyte ratio was depressed in those patients whose ratio was determined. Most patients showed some initial response to pentavalent antimonial therapy.

Treatment of atypical leishmaniasis with interferon gamma resulting in progression of Kaposi's sarcoma in an AIDS patient

Visceral leishmaniasis (kala-azar) affecting HIV-infected patient is being reported in increasing frequency. A 40-year-old German bisexual patient with full-blown AIDS is described who presented with Kaposi's sarcoma, epigastric pain, diarrhea, and weight loss but without fever. Leishmania amastigotes were initially found in biopsies from stomach, duodenum, and a cutaneous Kaposi's sarcoma lesion but were later also recovered from bone marrow and lymph node. The patient received three courses of a combination of pentavalent antimony and interferon-gamma. In addition to the common side effects such as fever, thrombocytopenia, and elevated amylase and lipase, a vivid progression of the Kaposi's sarcoma was noted. Tumor progression was temporally closely associated with treatment with interferon-gamma. Because this phenomenon has also been observed in other patients, we advise caution when using interferon-gamma in patients with Kaposi's sarcoma.

Laryngeal leishmaniasis as initial opportunistic disease in HIV infection

A case of laryngeal leishmaniasis, with symptoms of hoarseness and odinophagia which had developed over the past year, is presented. Clinical features and histological findings are discussed. Visceral leishmaniasis is increasingly associated with HIV infection and some authors have suggested the possibility of including it as a diagnostic criterium for AIDS in HIV-positive patients. When any case of leishmaniasis presents atypical clinical features, localization or treatment response in endemic areas, HIV infection should be ruled out.

Pancreatic lesions in HIV-infected patients

The pancreas is frequently involved during HIV infection, especially by disseminated infections or neoplasms. These lesions are generally asymptomatic and are discovered at autopsy. However, hypoglycaemia secondary to massive pancreatic infiltration by a tumour or tuberculous necrosis may occur. The most important cause of pancreatic dysfunction in HIV-infected patients is a drug toxic effect (intravenous pentamidine, didanosine, zalcitabine). Hypoglycaemia, which may or may not be followed by diabetes, can develop during intravenous pentamidine therapy. In cases with increased serum amylase and/or lipase levels, potentially toxic drugs must be promptly discontinued to avoid major pancreatic involvement.

Two cases of laryngeal leishmaniasis in patients infected with HIV

A high incidence of visceral leishmaniasis has been documented in HIV-infected patients in endemic areas. In these patients, atypical locations and a chronic course of the disease are more frequent. Two AIDS patients with laryngeal leishmaniasis are reported. These cases are believed to be the first of this type documented in the literature. The possible pathogenic mechanisms of the disease are discussed. Infection with Leishmania donovani may eventually be described for every organ containing phagocytic cells.

Isolated laryngeal leishmaniasis in an immunocompetent patient: successful treatment with surgery

The localization of Leishmania spp. in the larynx is rare but it has recently been described in patients infected by human immunodeficiency virus (HIV). The normal treatment given is antimonials. We describe a case of isolated leishmaniasis in the larynx which was cured by surgery. Our patient was a 47-year-old man who had suffered visceral leishmaniasis in his childhood with no immunosuppression.

Comparison of PCR with direct examination of bone marrow aspiration, myeloculture, and serology for diagnosis of visceral Leishmaniasis in immunocompromised patients

A PCR assay amplifying a repeated sequence from the Leishmania infantum genome was compared with direct examination of bone marrow aspirate, myeloculture, and serology for the diagnosis of visceral leishmaniasis in immunocompromised patients. Of 73 patients living in an area endemic for leishmaniasis and where visceral leishmaniasis was suspected by physicians, only 10 had an indisputable diagnosis of visceral leishmaniasis. None of the diagnostic tests performed in the study achieved 100% sensitivity for diagnosing visceral leishmaniasis. PCR exhibited superior sensitivity (82%) in comparison with bone marrow aspirate examination (55%) and myeloculture (55%). Our PCR assay also showed good specificity (97%), negative predictive value (97%), and positive predictive value (82%) even when all unconfirmed PCR results were scored as false positives. Serology exhibited good sensitivity (80%) and excellent specificity (100%), negative predictive value (98%), and positive predictive value (100%) in diagnosing new cases of visceral leishmaniasis but failed to diagnose relapses. We also observed consistent negative serological results using several different immunological detection methods for 2 of the 10 patients with confirmed cases of visceral leishmaniasis. This lack of serological reactivity persisted throughout the course of their infections. These results demonstrate the importance of using PCR as an aid in the diagnosis of visceral leishmaniasis in immunocompromised patients.

Visceral leishmaniasis in the acquired immunodeficiency syndrome: report of two cases

Core biopsies of the bone marrow are indispensable in the evaluation of fever of unknown etiology in human immunodeficiency virus-positive patients. We report two patients in whom visceral leishmaniasis was diagnosed based on the typical morphology, staining characteristics, and ultrastructure of the organisms.

Licochalcone A, a novel antiparasitic agent with potent activity against human pathogenic protozoan species of Leishmania

Licochalcone A, an oxygenated chalcone isolated from the roots of Chinese licorice plant, inhibited the growth of both Leishmania major and Leishmania donovani promastigotes and amastigotes. The structure of the licochalcone A was established by mass and nuclear magnetic resonance spectroscopies and by synthesis, and its purity was verified by high-pressure liquid chromatography. The 50% inhibition of growth of logarithmic- and stationary-phase promastigotes of L. major, as measured by [3H]thymidine uptake, were 4 and 2.5 micrograms/ml, respectively. The growth of L. major promastigotes was totally inhibited after a 20-h incubation period with licochalcone A at 5 micrograms/ml. At a concentration of 0.5 microgram/ml, licochalcone A markedly reduced the infection rate of human peripheral blood monocyte-derived macrophages and U937 cells with L. major promastigotes and exhibited a strong intracellular killing of the parasite. These data show that intracellular Leishmania amastigotes are more susceptible than promastigotes to licochalcone A. Results of studies on the site of action of licochalcone A indicate that the target organelle appears to be the parasite mitochondria. These findings demonstrate that licochalcone A in concentrations that are nontoxic to host cells exhibits a strong antileishmanial activity and that appropriate substituted chalcones might be a new class of antileishmanial drugs.

Lung diseases in the tropics. Part 1: Tropical granulomatous disorders of the lung: diagnosis and management

International travel, student and cultural exchanges and changing immigration patterns are insidiously transforming the face of medicine in the United States, Europe and other developed countries. It is essential that the practising clinician be aware of the increasing prevalence of various new and exotic tropical lung diseases. The definitive diagnosis of the pulmonary granulomas that constitute the bulk of lung disorders in the tropics is important since the treatment varies significantly. At the same time, recent developments in molecular biology, immunology and biochemistry have increased the diagnostic accuracy and therapeutic effectiveness related to tropical granulomatous disorders. Clinicians in the developing countries can now supplement their clinical acumen with rapid advances in immunology and histopathology enabling them to grasp the fundamental mechanisms of granuloma formation. Mycobacterial, fungal, parasitic, spirochetal and other infections must be differentiated from a variety of non-infectious granulomas including sarcoidosis, hypersensitivity pneumonitis, drug reaction and generalized vasculitis since therapy is vastly different. The treatment, if inappropriate, may not only be worthless but, in many cases, extremely harmful and even fatal.

Production of interferon-gamma and interleukin-4 by human T cells recognizing Leishmania lipophosphoglycan-associated protein

The Leishmania protein LPGAP which is co-isolated with lipophosphoglycan is a specific activator of T cells from individuals who have recovered from American leishmaniasis. We have tested the effect of LPGAP on peripheral blood mononuclear cells (PBMC) from Kenyan donors cured from L. donovani infections. LPGAP induced vigorous proliferation and production of interferon-gamma (IFN-gamma) by the cells. In addition PBMC incubated with LPGAP released interleukin-4 (IL-4) after pulsing with ionomycin and phorbol myristate acetate. Single cells were isolated from LPGAP-stimulated cell lines and expanded as T-cell clones. LPGAP-reactive T-cell clones were activated by crude preparations of both promastigotes and axenic grown amastigote-like parasites. Among 9 CD4+ T-cell clones recognizing LPGAP, cells secreting predominantly IFN-gamma as well as cells secreting predominantly IL-4 were identified. The results show that both IFN-gamma producing (Th1-like) and IL-4 producing (Th2-like) T cells recognizing LPGAP are expanded after infection with L. donovani in humans.

T-cell and cytokine responses in leishmaniasis

Intracellular pathogens, particularly those that inhabit lymphocytes and macrophages, represent unique challenges to the immune system. Leishmania are protozoan parasites that replicate exclusively in macrophages and are thus in an excellent position to influence lymphocyte responses. T cell responses are critical in determining the outcome of infections with Leishmania. In both murine and human infections, strong T helper type 2 responses have been associated with disease, and a decreased or absent T helper type 2 response has been associated with healing.

Leishmaniases of the New World: current concepts and implications for future research

Recent epidemiologic studies indicate that leishmaniasis in the Americas is far more abundant and of greater public health importance than was previously recognized. The disease in the New World is caused by a number of different parasite species that are capable of producing a wide variety of clinical manifestations. The outcome of leishmanial infection in humans is largely dependent on the immune responsiveness of the host and the virulence of the infecting parasite strain. This article reviews current concepts of the clinical forms, immunology, pathology, laboratory diagnosis, and treatment of the disease as well as aspects of its epidemiology and control. Recommendations for future research on the disease and its control are made.

Leishmania donovani-reactive Th1- and Th2-like T-cell clones from individuals who have recovered from visceral leishmaniasis

Infections in humans by Leishmania donovani parasites can result in a fatal disease, visceral leishmaniasis (VL), or in a self-limiting asymptomatic infection. In murine models of the infection employing Leishmania major, the course of the disease can be directed into a VL-like syndrome by interleukin-4 (IL-4)-producing Th2 cells, or cure may result by Th1 cells secreting gamma interferon (IFN-gamma). The present study examined the potential of human T cells to generate Th1 or Th2 responses to L. donovani. The profiles of IFN-gamma, IL-4, and lymphotoxin secretion after antigen stimulation were analyzed in a panel of L. donovani-reactive CD4+ human T-cell clones generated from individuals who had recovered from VL after antimonial treatment. Two of the T-cell clones produced large amounts of IL-4 without production of IFN-gamma, seven clones produced both IFN-gamma and IL-4, and eight produced only IFN-gamma. This is the first report of a Th1- and Th2-type response in human leishmaniasis. These results suggest that in analogy with murine models, there is a dichotomy in the human T-cell response to L. donovani infections. Preferential activation of IL-4-producing Th2-like cells may be involved in the exacerbation of human VL, whereas activation of IFN-gamma-producing Th1 cells may protect the host from severe disease. Identification of leishmanial antigens activating one or the other type of T cells will be important in the development of vaccines against leishmaniasis.

Acquired immunodeficiency syndrome-related visceral leishmaniasis presenting in a pleural effusion

Visceral leishmaniasis is increasingly reported in immunocompromised patients, including patients with AIDS. We report a case of visceral leishmaniasis in an AIDS patient who presented with pulmonary symptoms and bilateral pleural effusions. Histologic evaluation of pleural fluid and bone marrow revealed histiocytes with intracellular Leishmania amastigotes. Visceral leishmaniasis should be considered in AIDS patients with a significant travel history who present with unexplained pulmonary symptoms.

Visceral leishmaniasis after orthotopic liver transplantation: impact of persistent splenomegaly

Visceral leishmaniasis was observed in a 50-year-old female liver transplant recipient 1 year following transplantation. Signs of active infection were low-grade fever, pancytopenia, persistent splenomegaly, positive cultures for leishmania in liver and bone marrow biopsy specimens, and newly positive leishmania serology. Following sequential therapy with pentavalent antimony and amphotericin B, blood values improved massively, bone marrow cultures became negative, and leishmania serology decreased. Secondary prophylaxis with fluconazole was instituted and the patient remains without signs of active infection 1 year after successful therapy.

AIDS: Part II

Great strides have been made in the therapy of human immunodeficiency virus (HIV) infection. Currently approved drugs include zidovudine and didanosine. A third drug, dideoxycytidine (zalcitibine), has recently been filed for approval with the Food and Drug Administration. All these drugs work through inhibition of the reverse transcriptase enzyme. Zidovudine is the only drug that has shown clinical efficacy against HIV. Treatment of patients with advanced HIV disease (i.e., acquired immune deficiency syndrome [AIDS] or symptomatic infection with < 200 CD4+ lymphocytes per mm3), results in a prolongation and improved quality of life. Zidovudine is the only antiretroviral agent approved for the treatment of asymptomatic patients. Early intervention with zidovudine has been shown to delay progression to AIDS when patients' CD4+ lymphocyte counts decline to less than 500/mm3, irrespective of clinical signs or symptoms of HIV infection. Didanosine is currently indicated for the treatment of patients with advanced HIV disease who are intolerant to or failing zidovudine therapy. The major toxicity of zidovudine is bone marrow suppression with anemia and granulocytopenia (which occurs in from 1% to 45% of patients, depending on the clinical stage of disease and the dose of the drug). Didanosine and zalcitibine have both been associated with a severe peripheral neuropathy, which is generally reversible on cessation of the drug. In addition, didanosine has been implicated as a cause of pancreatitis that has been fatal in a small percentage of cases. The toxicities of didanosine and zalcitibine range from 1% to 10%, depending on dose, duration of therapy, and the presence of underlying HIV-related peripheral neuropathy or a previous history of pancreatitis. The clinical hallmark of HIV infection is the development of opportunistic infections and malignancies, which are a consequence of the profound immunodeficiency. The risk of an opportunistic infection increases significantly as the T-helper lymphocyte count declines to less than 20%, or 200 to 250/mm3. The spectrum of opportunistic infections ranges from viruses to protozoa. Patients with advanced HIV disease are also at increased risk of infection with nonopportunistic, community-acquired pathogens. Primary and secondary prophylaxis against the most common AIDS-defining opportunistic infection, Pneumocystis carinii pneumonia, is now recommended. Studies are currently underway to determine the efficacy of prophylaxis against other opportunistic pathogens. Treatment of opportunistic infections associated with AIDS has improved significantly over the past 5 years as new drugs and combination regimens of antimicrobials have been developed.(ABSTRACT TRUNCATED AT 400 WORDS)

Recognition of Leishmania antigens by T lymphocytes from nonexposed individuals

Crude antigen preparations of Leishmania promastigote sonicates were found to induce in vitro proliferation and gamma interferon production in peripheral blood mononuclear cells (PBMC) from individuals without known exposure to the parasite. The proliferating cells were mainly CD2-positive T cells. The proliferative response was maximal after more than 6 days of incubation with the antigens in contrast to the proliferation induced by the mitogenic lectin phytohemagglutinin (PHA), which peaked after 3 to 5 days. Judged by limiting dilution analysis, the frequencies of antigen-reactive precursor cells were less than 1:10,000 and varied considerably between individuals. Depletion of CD45R0-positive (memory) cells from the PBMC abolished proliferative responses induced by Leishmania antigen and by tetanus toxoid. In cell populations depleted of CD45RA-positive (naive) cells, only a small reduction in response was observed. Cell populations depleted of either CD45R0-positive cells or CD45RA-positive cells both responded to PHA. We conclude that presumably unexposed individuals have a low number of Leishmania-reactive T cells in their circulatory systems. The Leishmania-reactive T cells in these individuals are most likely memory cells recognizing antigens present both in the Leishmania preparations and in the environment.

Hepatobiliary complications in patients with human immunodeficiency virus infection

Human immunodeficiency virus (HIV) infection has been associated with a number of hepatic and biliary tract disorders. Case reports, series of liver biopsies, and postmortem studies that examined the hepatobiliary system were retrieved with a MEDLARS search and form the basis of this review. The liver and biliary tract are frequently involved with opportunistic infections (most commonly mycobacteria and cytomegalovirus) and neoplasms (mainly Kaposi's sarcoma) in patients with HIV infection. The patients are often asymptomatic but may have elevated levels of serum liver enzymes. These abnormalities are nonspecific. Sulfa drugs, pentamidine, and ketoconazole are the medications used in HIV-related infections that are most likely to result in abnormalities on liver tests. Acalculous cholecystitis and sclerosing cholangitis also occur in HIV infection. Cytomegalovirus and Cryptosporidium are the organisms most commonly associated with these conditions. Imaging studies of the liver may detect parenchymal abnormalities and guide liver biopsy. The role of this procedure in the diagnosis of opportunistic infections and neoplasms is controversial because these lesions are generally disseminated at the time liver abnormalities are evident. A liver biopsy is best used when other less invasive procedures have failed to provide a diagnosis. Endoscopic retrograde cholangiopancreatography is a useful diagnostic procedure with therapeutic potential in patients with abdominal pain, fever, or an elevated serum alkaline phosphatase level.

HIV-Leishmania co-infections in Italy. Isoenzyme characterization of Leishmania causing visceral leishmaniasis in HIV patients

Visceral leishmaniasis (VL) infections in patients with human immunodeficiency virus (HIV) infection are dramatically increasing in Mediterranean countries such as Spain, France and Italy. A study has been carried out to characterize biochemically the agents of typical or unusual VL in subjects with HIV infection and to compare results with those obtained so far from VL and cutaneous leishmaniasis (CL) infections in HIV negative subjects. Twelve Leishmania stocks were isolated from 8 HIV patients and typed through the electrophoretic analysis of 14 isoenzymes. All the stocks were identified as L. infantum s.l. According to zymodeme classification, the results can be summarized as follows: (i) only half of the subjects were infected with the expected commonest viscerotropic zymodeme in the Mediterranean area, MON 1; (ii) 2 patients were infected with the most widespread agent of CL in Italy, L. infantum MON 24; (iii) one subject was found infected with a zymodeme (MON 78) which, so far, has been found only in Malta as an agent of CL; (iv) one subject was infected with a new zymodeme, MON 136, which shares biochemical characteristics with 2 dermotropic L. infantum zymodemes, MON 78 and MON 111. Thus, half of the HIV patients surveyed displayed severe visceralization of parasites usually showing low virulence in HIV negative subjects.

Rapid and definitive diagnosis of infectious diseases using peripheral blood smears

A timely diagnosis is essential in the management of septicemia and septic shock. Three patients are described, all of whom presented with fever and one of whom was hypotensive at the time of admission. In each patient, rapid diagnosis of the cause of fever was possible because microorganisms were identified on a peripheral blood smear obtained at the time of admission. This identification permitted prompt initiation of appropriate antimicrobial therapy. In addition, a literature review of use of peripheral blood smears in the diagnosis of bacterial, fungal, and parasitic infections is provided.

Interactions between immunity and chemotherapy in the treatment of the trypanosomiases and leishmaniases

The immune status of a host infected with Trypanosoma spp. or Leishmania spp. can play an important role in successful chemotherapy. In animal models, treatment of African trypanosomiasis with difluoromethylornithine or melarsoprol requires an appropriate antibody-mediated immune response. An intact immune system is also necessary for rapid clearance of trypanosomes from the bloodstream following treatment with suramin or quinapyramine. Similarly, an efficient cell-mediated immune responses is required for maximal efficacy of pentavalent antimonials in the treatment of leishmaniasis. However, the potential relationship between parasite-induced or acquired immunosuppression and effective chemotherapy has been poorly studied. Macrophages which have been activated by bacterial cell wall components or gamma-interferon are known to display increased activity against Leishmania donovani or Trypanosoma cruzi. In experimental and clinical visceral leishmaniasis, use of macrophage activators together with pentavalent antimonials has lowered the dose of antimony required to cure the infection.

Visceral leishmaniasis in an HIV-infected patient: clinical features and response to treatment

We report the case of 43-year-old homosexual patient with HIV infection and a history of travel to the Far East in whom visceral leishmaniasis was the first infectious complication. Symptoms were fever, malaise, weight loss, hepatosplenomegaly, generalized lymphadenopathy, and oral thrush. Laboratory abnormalities included a slight elevation of liver enzymes, impairment of liver function tests, leukocytopenia, anemia, hypergammaglobulinemia, and markedly depressed CD4(+)-cell counts. Despite initially successful treatment with pentavalent antimony, a relapse of leishmaniasis occurred after 7 months. Eradication of the infection was not achieved. Treatment was continued as a palliative chronic suppressive treatment with fortnightly pentamidine infusions. The clinical course was complicated by legionella pneumonia and the development of rapidly progressing Kaposi's sarcoma. The case is presented in detail, and the influence of HIV infection on the course of leishmaniasis is discussed.

Visceral leishmaniasis in patients infected with human immunodeficiency virus. Co-operative Group for the Study of Leishmaniasis in AIDS

We describe 40 HIV-seropositive patients who developed visceral leishmaniasis. All the patients lived in areas endemic for visceral leishmaniasis and belonged to groups at risk for AIDS. Twenty-three patients (57.2%) had definitive AIDS before or after diagnosis of leishmaniasis and 77.5% were classified as belonging to CDC group IV. Fever was present in 95% patients and enlargement of the liver and/or spleen in 92.5%. Lymphopenia was found in 78.3%, depression of the absolute number of CD4 lymphocytes in 90% and depression of the CD4 to CD8 ratio in all evaluated cases but leishmania antibodies were found in only 35.2%. Parasites were demonstrated in the bone marrow or liver in every case. Thirty patients (75%) showed an initial good response to antimonial drugs, although the leishmaniasis followed a chronic or relapsing course in 17 (42.5%). HIV-related mortality was 40%. A significant correlation was found only between the relapsing course of the disease and mortality. In a multivariate linear regression model, the relapsing course was the only variable that influenced mortality. Visceral leishmaniasis is an opportunistic disease that should be suspected in HIV-infected patients. We suggest that it should be included in the CDC group IV C-1 and considered as a disease indicative of AIDS.