Visceral leishmaniasis (Kala-Azar) in transplant recipients: case report and review

An Atypical Course of Visceral Leishmaniasis After Kidney Transplantation: A Case Report From Iran

BACKGROUND

Organ transplantation can lead to human visceral leishmaniasis (VL) transmission in humans. This report aims to describe the possible complications related to an atypical course of VL after kidney transplantation.

CASE PRESENTATION

A 61-year-old man who suffered end-stage renal failure received a deceased donor kidney transplant after 2 years of hemodialysis. Tacrolimus, mycophenolate mofetil, and prednisolone were used for immunosuppressive therapy, and renal function remained stable for 2.5 years. He was referred to our hospital because of fever and malaise. Physical and radiological examinations showed mild splenomegaly and cervical and inguinal lymphadenopathy. Laboratory data showed bicytopenia, elevated C-reactive protein, serum creatinine, and non-nephrotic proteinuria. Bone marrow biopsy aspiration showed no abnormality. Polymerase chain reaction confirmed the diagnosis of Leishmania infantum. Anti-leishmanial therapy was initiated with liposomal amphotericin B for 2 weeks, and the patient became clinically stable. So far, there has been no evidence of clinical or biological relapse, and kidney function is stable.

CONCLUSIONS

Considering that VL has become increasingly widespread in immunocompromised patients in endemic regions, especially in patients with transplants, it is crucial to screen and rule out VL as a cause of infection in these patients. The probability of this problem should be considered in every patient with a transplant in endemic and nonendemic areas. Furthermore, our study showed that through timely diagnosis using noninvasive methods and standard treatments, mortality caused by this disease can be properly prevented.

Updated diagnosis and graft involvement for visceral leishmaniasis in kidney transplant recipients: a case report and literature review

Purpose

Visceral leishmaniasis (VL) has become a rising concern to transplantation teams, being associated with graft dysfunction and reduced survival of renal transplant recipients. Here, we describe a case of VL occurring in a kidney transplant (KT) recipient in Italy, a country in which Leishmania infantum is endemic and we reviewed the literature on the clinical course and diagnosis of VL in KT recipients residing or travelling to southern Europe.

Results

The VL case was diagnosed 18 months after transplant and 28 days after the onset of symptoms by quantitative PCR (qPCR) on peripheral blood. A graft biopsy showed renal involvement, and PCR performed on graft tissue displayed the presence of Leishmania DNA. The retrospective confirmation of Leishmania-positive serology in a serum sample collected before transplantation, as well as the absence of anti-Leishmania IgG in the graft donor strongly suggest that reactivation of a latent parasitic infection caused VL in the current case.

Conclusion

VL is often underdiagnosed in transplant recipients, despite the presence of latent Leishmania infection being reported in endemic countries. This case report, as well as the literature review on leishmaniasis in KT recipients, underline the importance of rapid VL diagnosis to promptly undergo treatment. Serology is scarcely sensitive in immunocompromised patients, thus molecular tests in peripheral blood should be implemented and standardized for both VL identification and follow-up.

Epidemiology, Clinical Characteristics, Diagnostic Work Up, and Treatment Options of Leishmania Infection in Kidney Transplant Recipients: A Systematic Review

Current knowledge on Leishmania infection after kidney transplantation (KT) is limited. In order to offer a comprehensive guide for the management of post-transplant Leishmaniasis, we performed a systematic review following the latest PRISMA Checklist and using PubMed, Scopus, and Embase as databases. No time restrictions were applied, including all English-edited articles on Leishmaniasis in KT recipients. Selected items were assessed for methodological quality using a modified Newcastle–Ottawa Scale. Given the nature and quality of the studies (case reports and retrospective uncontrolled case series), data could not be meta-analyzed. A descriptive summary was therefore provided. Eventually, we selected 70 studies, describing a total of 159 cases of Leishmaniasis. Most of the patients were adult, male, and Caucasian. Furthermore, they were frequently living or travelling to endemic regions. The onset of the disease was variable, but more often in the late transplant course. The clinical features were basically similar to those reported in the general population. However, a generalized delay in diagnosis and treatment could be detected. Bone marrow aspiration was the preferred diagnostic modality. The main treatment options included pentavalent antimonial and liposomal amphotericin B, both showing mixed results. Overall, the outcomes appeared as concerning, with several patients dying or losing their transplant.

Donor acquired visceral leishmaniasis following liver transplantation

Patients who undergo solid organ transplantation are at risk of opportunistic infection associated with immunosuppression. We report a case of confirmed donor derived visceral leishmaniasis (VL), in a patient following liver transplantation causing fever and pancytopenia. The diagnosis was confirmed by bone marrow biopsy, with confirmed positive donor serology, with no other route of transmission. To our knowledge, this is the first case report in the United Kingdom and Europe, of confirmed organ donor transmission of VL. This case report highlights an important consideration of donor derived infections, in the context of solid organ transplantation.

Presence of anti-Leishmania antibodies in candidates for kidney transplantation

OBJECTIVES

Visceral leishmaniasis (VL) is a progressive disease that, left untreated, is typically fatal. The purpose of this investigation was to detect Leishmania sp. infection in hemodialysis patients who had received multiple blood transfusions at a private clinic in Campo Grande, Mato Grosso do Sul state, Midwest Brazil.

METHODS

Fifty randomly selected volunteers were interviewed for collection of demographic, socioeconomic, and epidemiological data. Indirect immunofluorescence (titers positive when ≥1:40) and rK39 immunochromatographic tests were employed for serological investigation.

RESULTS

Males predominated (60%). Age ranged from 20 to 77 years. Most subjects reported being on hemodialysis for at least one year (94%) and 84% were candidates for kidney transplantation, 67% of whom were on the waiting list. Leishmania sp. infection was detected in 32%. Contact with infected dogs was the only variable associated with infection.

CONCLUSIONS

Under immunocompromised conditions, VL is opportunistic and potentially fatal. Despite existing risks, screening for VL is not performed in asymptomatic donors and recipients. The detection of anti-Leishmania antibodies in these patients reinforces the need for infection screening before immunosuppressive treatment is initiated to reduce not only the risks of VL development and severity, but also mortality rates in cases of reactivation of latent infection.

Leishmania donovani and Pneumocystis jirovecii (carinii) diagnosed on bronchoalveolar lavage cytology in a liver transplant recipient with Cytomegalovirus infection

Liver transplant recipients are prone to several infections, including lung infections, which can lead to substantial morbidity and mortality. Bronchoalveolar lavage (BAL) cytology is a rapid and sensitive diagnostic tool to identify the etiologic agents. We report a rare case of a 24-year-old male, post Live donor liver transplantation for autoimmune chronic liver disease, who presented with cough, fever, weight loss, and cavitatory lesion in lung. BAL cytology revealed Leishmania donovani (LD) and Pneumocystis jirovecii/carinii (PCP). Cytomegalovirus deoxyribonucleic acid polymerase chain reaction (CMV DNA PCR) test showed markedly raised levels. Patient was put on treatment for these multiple infections and showed significant improvement. Thus, rapid diagnosis of infections through BAL cytology is crucial in transplant recipients to institute timely therapy and avoid undesirable empirical treatments. Moreover, this case highlights a rare finding of LD bodies along with PCP in BAL cytology.

Solid Organ Transplant and Parasitic Diseases: A Review of the Clinical Cases in the Last Two Decades

The aim of this study was to evaluate the occurrence of parasitic infections in solid organ transplant (SOT) recipients. We conducted a systematic review of literature records on post-transplant parasitic infections, published from 1996 to 2016 and available on PubMed database, focusing only on parasitic infections acquired after SOT. The methods and findings of the present review have been presented based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) checklist. From data published in the literature, the real burden of parasitic infections among SOT recipients cannot really be estimated. Nevertheless, publications on the matter are on the increase, probably due to more than one reason: (i) the increasing number of patients transplanted and then treated with immunosuppressive agents; (ii) the “population shift” resulting from immigration and travels to endemic areas, and (iii) the increased attention directed to diagnosis/notification/publication of cases. Considering parasitic infections as emerging and potentially serious in their evolution, additional strategies for the prevention, careful screening and follow-up, with a high level of awareness, identification, and pre-emptive therapy are needed in transplant recipients.

Allogeneic hematopoietic stem cell transplant recipients and parasitic diseases: A review of the literature of clinical cases and perspectives to screen and follow-up active and latent chronic infections

BACKGROUND

Allogeneic hematopoietic stem cell transplant (HSCT) recipients are at substantial risk for a variety of infections depending upon numerous factors, such as degree of immunosuppression, host factors, and period after transplantation. Bacterial, fungal, viral, as well as parasitic infections can occur with high morbidity and mortality.

OBJECTIVES

The aim of this study was to evaluate the magnitude of the occurrence of parasitic infections in allogeneic HSCT recipients. Modalities of transmission, methods of diagnosis, treatment, donor and recipient pre-transplant screening and prevention measures of the most serious parasitic infections have also been discussed.

MATERIALS AND METHODS

We systematically reviewed literature records on post-transplant (allogeneic HSCT) parasitic infections, identified through PubMed database searching, using no language or time restrictions. Search was concluded on December 31, 2015. In the present review, we only discussed post-transplant parasitic infections in allogeneic HSCT. Only exclusion criteria were absence of sufficient information on the transmission of parasitic infection to the recipient. Autologous HSCT recipients have not been included because of the absence of a proper allogeneic transplantation even in presence of blood or blood product transfusions. The methods and findings of the present review have been reported based on the preferred reporting items for systematic reviews and meta-analysis checklist (PRISMA).

RESULTS

Regarding allogeneic HSCT recipients, from data published in the literature the real burden of parasitic infections cannot be really estimated. Nevertheless, a positive trend on publication number exists, probably because of more than one reason: (i) the increasing number of patients transplanted and then treated with immunosuppressive agents, (ii) the "population shift" resulting from immigration and travels to endemic areas, and (iii) the increasing of attention for diagnosis/notification/publication of cases.

CONCLUSIONS

Considering parasitic infections as emerging and potentially serious in their evolution, additional strategies for the prevention, careful screening and follow-up, with a high level of suspicion, identification, and preemptive therapy are necessary in transplant recipients.

PERSPECTIVES

The Authors' viewpoint in the perspective to screen and follow-up active and latent chronic parasitosis in stem cells donors and recipients: a proposal for a flow chart.

Leishmaniasis in solid organ and hematopoietic stem cell transplant recipients

Leishmaniasis occurs in <1% of solid organ and hematopoietic stem cell transplant recipients in endemic countries in which transplants are performed. Visceral leishmaniasis (VL) makes up the bulk of reported cases. The onset generally occurs months after transplantation and the mode of acquisition is often impossible to determine, but de novo vector-borne infection and reactivation of inapparent infection are thought to be the principal means. The potential role of clinically inapparent donor infection is uncertain and screening is not currently recommended, nor is it recommended for recipients from endemic areas, some of whom may have detectable circulating protozoan nucleic acid. While transplant recipients with VL often present with the non-specific findings of fever and cytopenia, the additional presence of hepatosplenomegaly in patients from endemic areas should lead to a directed diagnostic evaluation with bone marrow examination and PCR testing of marrow and peripheral blood having a high yield. Management may often be complicated by the presence of concomitant infections. A lipid formulation of amphotericin B is the preferred treatment, especially for VL, but the relapse rate in transplant recipients is approximately 25%. PCR monitoring of blood for either secondary prophylaxis or preemptive therapy requires further study.

PANCREATIC TOXICITY AS AN ADVERSE EFFECT INDUCED BY MEGLUMINE ANTIMONIATE THERAPY IN A CLINICAL TRIAL FOR CUTANEOUS LEISHMANIASIS

American tegumentary leishmaniasis is an infectious disease caused by a protozoan of the genus Leishmania. Pentavalent antimonials are the first choice drugs for cutaneous leishmaniasis (CL), although doses are controversial. In a clinical trial for CL we investigated the occurrence of pancreatic toxicity with different schedules of treatment with meglumine antimoniate (MA). Seventy-two patients were allocated in two different therapeutic groups: 20 or 5 mg of pentavalent antimony (Sb5+)/kg/day for 20 or 30 days, respectively. Looking for adverse effects, patients were asked about abdominal pain, nausea, vomiting or anorexia in each medical visit. We performed physical examinations and collected blood to evaluate serum amylase and lipase in the pre-treatment period, and every 10 days during treatment and one month post-treatment. Hyperlipasemia occurred in 54.8% and hyperamylasemia in 19.4% patients. Patients treated with MA 20 mg Sb5+ presented a higher risk of hyperlipasemia (p = 0.023). Besides, higher MA doses were associated with a 2.05 higher risk ratio (p = 0.003) of developing more serious (moderate to severe) hyperlipasemia. The attributable fraction was 51% in this group. Thirty-six patients presented abdominal pain, nausea, vomiting or anorexia but only 47.2% of those had hyperlipasemia and/ or hyperamylasemia. These findings suggest the importance of the search for less toxic therapeutic regimens for the treatment of CL.

Is leishmaniasis an "unusual suspect" of infection in allogeneic transplantation?

Leishmaniasis is a disease of the immunocompetent population, more often affecting infants and young children. However, the number of leishmaniasis cases associated with immunosuppression has increased over the last 20 years. The visceral form of the disease, visceral leishmaniasis (VL), is identified as an opportunistic infection in immunosuppressed individuals, occurring mainly after solid organ transplantation, especially in renal transplant recipients. Limited data are available about VL after hematopoietic stem cell transplantation (HSCT). We report the cases of 3 patients with late VL after allogeneic HSCT, and review the literature.

Progress in the treatment of a neglected infectious disease: visceral leishmaniasis

Visceral leishmaniasis (kala-azar) is a disseminated intracellular protozoal infection. Most cases (90%) occur in the rural regions of five countries: India, Sudan, Nepal, Bangladesh and Brazil. As with other infectious diseases embedded in high-level poverty, developing and/or delivering new treatments for visceral leishmaniasis had been painfully slow or nonexistent. However, despite persistent unresolved obstacles (e.g., drug affordability), renewed interest in visceral leishmaniasis and numerous successful treatment trials have combined to turn a therapeutic corner in the past 5 years, yielding new alternatives to conventional pentavalent antimony. Advances include the use of low-cost generic pentavalent antimony, rediscovery of amphotericin B, short-course regimens via lipid formulations of amphotericin B, retesting injectible paromyomycin and, of clear-cut importance, identifying miltefosine (Impavido, Zentaris) as the first effective oral therapy for this neglected disease.

Visceral leishmaniasis after kidney transplantation: report of a new case and a review of the literature

Visceral leishmaniasis (VL) is a parasitic disease, caused by protozoa of the genus Leishmania, transmitted by the phlebotomies sand fly. In the last 20 years, the increasing frequency of organ transplantations and the improvement of associated immunosuppressive treatments have led to the recognition of several cases of VL complicating organ transplantation. Actually, less than 100 cases of VL after kidney transplantation are reported in the literature. In this context, VL is fatal without antileishmanial treatment which constitutes a difficult challenge. We report a case of VL in Tunisian renal transplant recipient treated successfully by liposomal amphotericin B (Ambisome®, Gilead Sciences Inc). Also, we review the epidemiological, clinical, biological and therapeutic aspects of VL associated with renal transplantation reported in the literature. Our report identifies that VL should be suspected in renal transplant recipients presenting unexplained fever, splenomegaly and pancytopeny. It also suggests a serological testing for leishmaniasis in the pre-operative check-up of transplant patients and donors living or traveling in endemic areas of leishmaniasis. Moreover, recipients should be tested regularly for leishmaniasis after transplantation. Liposomal amphotericin B may be considered the treatment of choice of VL, since it has a lower incidence of side effects.

Parasitic infections in solid organ transplant recipients

Parasitic diseases are rare infections after a solid organ transplant (SOT). Toxoplasmosis, Trypanosoma cruzi, and visceral leishmanias are the 3 main opportunistic protozoal infections that have the potential to be lethal if not diagnosed early and treated appropriately after SOT. Strongyloides stercoralis is the one helminthic disease that is life-threatening after transplant. This review addresses modes of transmission, methods of diagnosis, and treatment of the most serious parasitic infections in SOT. The role of targeted pretransplant screening of the donor and recipient for parasitic diseases is also discussed.

Atypical presentation of cutaneous leishmaniasis in a renal transplant recipient successfully treated with allopurinol and fluconazole

Leishmaniasis is a zoonotic infection acquired through the bite of a female sandfly, which introduces the amastigotes of Leishmania into the bloodstream. Cutaneous leishmaniasis is rare after solid organ transplantation. Its diagnosis is difficult in immunosuppressed patients. We report a case of isolated cutaneous leishmaniasis in a renal transplant patient resident in an endemic area. The patient was successfully treated with allopurinol and fluconazole and has remained relapse-free for 44 months. The diagnosis of cutaneous leishmaniasis must be considered in immunosuppressed patients living in endemic areas. Our report shows that cutaneous leishmaniasis may complicate the clinical course of kidney transplant recipients and its presentation can be atypical. Conventional treatment with pen.tavalent antimonial agents can cause many side effects; of particular concern in renal transplant pa.tients are pancreatitis and nephrotoxicity. These latter may be avoided by using a combination of allopurinol and fluconazole.

Parasitic infections in solid-organ transplant recipients

PURPOSE OF REVIEW

To provide an updated perspective of the most common parasitic infections occurring in solid-organ transplant (SOT) recipients.

RECENT FINDINGS

Parasitic infections are an emerging problem in SOT programs and represent a diagnostic and therapeutic challenge. Transplantation in endemic areas - including medical tourism, international travel and migration - justify the necessity of considering parasitic infections in the differential diagnosis of posttransplant complications. Molecular techniques, such as PCR, may improve the diagnostic accuracy and help during the follow-up.

SUMMARY

Parasitic infections are an uncommon but potentially severe complication in SOT recipients. An increase of donors emigrated from tropical areas and more posttransplant patients traveling to endemic areas have led to a rise in parasitic infections reported among SOT recipients. Transplant physicians should get familiar with parasitic infections and promote adherence to preventive measures in SOT recipients.

Probing elongating and branching β-D-galactosyltransferase activities in Leishmania parasites by making use of synthetic phosphoglycans

Protozoan parasites of the genus Leishmania synthesize lipophosphoglycans (LPGs), phosphoglycans and proteophosphoglycans that contain phosphosaccharide repeat units of [-6)Gal(β1-4)Man(α1-OPO(3)H-]. The repeat structures are assembled by sequential addition of Manα1-OPO(3)H and β-Gal. In this study, an UDP-Gal-dependent activity was detected in L. donovani and L. major membranes using synthetic phospho-oligosaccharide fragments of lipophosphoglycan as acceptor substrates. Incubation of a microsomal preparation from L. donovani or L. major parasites with synthetic substrates and UDP-[6-(3)H]Gal resulted in incorporation of radiolabel into these exogenous acceptors. The [(3)H]galactose-labeled products were characterized by degradation into radioactive, low molecular mass fragments upon hydrolysis with mild acid and treatment with β-galactosidases. We showed that the activity detected with L. donovani membranes is the elongating β-d-galactosyltransferase associated with LPG phosphosaccharide backbone biosynthesis (eGalT). The eGalT activity showed a requirement for the presence of at least one phosphodiester group in the substrate and it was enhanced dramatically when two or three phosphodiester groups were present. Using the same substrates we detected two types of galactosyltransferase activity in L. major membranes: the elongating β-d-galactosyltransferase and a branching β-d-galactosyltransferase (bGalT). Both L. major enzymes required a minimum of one phosphodiester group present in the substrate, but acceptors with two or three phosphodiester groups were found to be superior.

Parasitic infections in solid organ transplant recipients

Parasitic infections are an uncommon but potentially severe complication in solid organ transplant (SOT) recipients. An increase in donors who have emigrated from tropical areas and more transplant recipients traveling to endemic areas have led to a rise in parasitic infections reported among SOT recipients. Clinicians should include these infections in their differential diagnosis and promote adherence to preventive measures in SOT recipients.

Visceral leishmaniasis in a kidney transplant recipient: parasitic interstitial nephritis, a cause of renal dysfunction

Visceral leishmaniasis (VL) due to Leishmania infantum is an endemic parasitic infection in the Mediterranean area. It most commonly affects immunosuppressed individuals, especially HIV patients and less frequently organ transplant recipients. Renal involvement seems to be frequent and is mostly associated with tubulointerstitial nephritis, as described in autopsy reports. In the 61 cases of renal transplant recipients with VL reported in the literature, renal dysfunction was noted at clinical presentation and was more frequently observed as a complication of antiparasitic therapy. However, no pathological analysis of the allograft lesions was reported. We present the case of a Swiss renal transplant recipient who developed VL after vacations in Spain and Tunisia, complicated by acute parasitic nephritis in the renal allograft 3 months after a well-conducted treatment of liposomal amphotericin B.

Visceral Leishmaniasis Revealing Chronic Granulomatous Disease in a Child

We report the first description of visceral leishmaniasis (VL) infection as a harbinger of chronic granulomatous disease (CGD) in a 3-year old child. Although VL is not frequently suspected in CGD patients, our case emphasises the importance of a complete evaluation of the immune system in children presenting with VL in order to exclude underlying immunodeficiency states. As the prognosis of CGD is poor, with high morbidity and mortality, establishing an early diagnosis has important practical implications in the successful treatment of these patients. Following the diagnosis, the patient received Human Leukocyte Antigen (HLA) identical sibling bone marrow transplantation (BMT). The child is now 2 years post-transplant and is in good general conditions with normal blood counts, and evidence of full-donor chimerism in repeated fluorescence in situ hybridization (FISH) studies.

The leishmaniases--survival and expansion in a changing world. A mini-review

The number of cases of visceral and cutaneous leishmaniasis is increasing globally at an alarming rate irrespective of the region and the leishmaniases are amongst the top emergent diseases in spite of control measures. In the present review attention is drawn to some of the reasons for this. The leishmaniases have expanded beyond their natural ecotopes due to the ecological chaos caused by man and this in turn affects the levels of his exposure to the vectors. Examples of how different phenomana (such as war, civilian migration, immuno-suppression caused by medication and viral infections, globalization of work and leisure and transmission outside endemic areas) contribute to the spread and increase of the disease are discussed.

Leishmaniasis among organ transplant recipients

Leishmaniasis is a rarely reported disease among transplant recipients; however, the number of published cases has quadrupled since the beginning of the 1990s. Most cases have been observed in patients living in countries of the Mediterranean basin. Leishmaniasis is most commonly associated with kidney transplantation (77%), and cases are also recorded among patients undergoing liver, heart, lung, pancreas, and bone marrow transplantation. Visceral leishmaniasis (VL) is the most frequently observed clinical presentation, followed by mucosal leishmaniasis and more rarely cutaneous leishmaniasis. Transplant recipients with VL develop the classic clinical form of the disease, which is a febrile hepatosplenic and pancytopenic syndrome. Immunodepression seems to predispose to development of mucosal leishmaniasis caused by viscerotropic strains. Early diagnosis of VL is crucial for patient therapy and outcome; however, this is frequently overlooked or delayed in transplant patients. Pentavalent antimonials are the most commom form of treatment for VL, but have a high incidence of toxicity (34%). Although used in fewer patients, liposomal amphotericin B seems to be better tolerated and should be considered as first-line therapy in transplant recipients.

Transmission of tropical and geographically restricted infections during solid-organ transplantation

In recent years, the increasing number of donors from different regions of the world is providing a new challenge for the management and selection of suitable donors. This is a worldwide problem in most countries with transplantation programs, especially due to the increase in immigration and international travel. This paper elaborates recommendations regarding the selection criteria for donors from foreign countries who could potentially transmit tropical or geographically restricted infections to solid-organ transplant recipients. For this purpose, an extensive review of the medical literature focusing on viral, fungal, and parasitic infections that could be transmitted during transplantation from donors who have lived or traveled in countries where these infections are endemic has been performed, with special emphasis on tropical and imported infections. The review also includes cases described in the literature as well as risks of transmission during transplantation, microbiological tests available, and recommendations for each infection. A table listing different infectious agents with their geographic distributions and specific recommendations is included.

Liver transplant recipient with concomitant cutaneous and visceral leishmaniasis

Diagnosis of leishmaniasis in immunosuppressed patients may be a serious challenge for physicians because of the major clinical and laboratory differences with immunocompetent patients. In immunosuppressed patients, the disease is characterized usually by disseminated visceral involvement, atypical cutaneous lesions and persistent negativity of diagnostic tests. Here, we report an eight-yr-old liver transplant recipient with concomitant cutaneous and visceral leishmaniasis in whom the cutaneous lesion led to the diagnosis of systemic involvement.

Comparative protein modeling and surface analysis of Leishmania sirtuin: A potential target for antileishmanial drug discovery

Homology model of Leishmania SIR2 shed new light on the ligand binding features of this enzyme. The molecular electrostatic potentials (MESP), the cavity depth analysis, and LmSIR2-hSIRT2 models' superposition suggested that the nicotinamide binding catalytic domain has several minor but potentially important structural differences. These differences could be exploited for designing antileishmanial compounds.

Reactivation of dormant cutaneous Leishmania infection in a kidney transplant patient

BACKGROUND

Leishmaniasis is an infection caused by a protozoan parasite belonging to genus Leishmania and transmitted by the Phlebotomus sandfly. Clinical presentations of infection include visceral, cutaneous, and mucocutaneous forms. Leishmaniasis is endemic in Africa, Asia, Europe, South America, and southern part of North America. This infection is extremely rare in the US and is mostly found among travelers coming from endemic areas. Cases of cutaneous and visceral leishmaniasis have been reported in organ transplant recipients in endemic areas.

CASE REPORT

We describe a case of cutaneous leishmaniasis in a kidney transplant patient, originally from Bolivia, who resides in the area known to be non-endemic for leishmaniasis and who is known not to travel within or outside of the US after the transplantation.

RESULTS

Histologic examination of cutaneous lesion revealed extensive subcutaneous lymphohistiocytic inflammation with clusters of amastigote within histiocytes.

CONCLUSION

To our knowledge, this is the first case of cutaneous leishmaniasis in a kidney transplant patient residing in the US in an area known to be non-endemic for leishmaniasis, probably after reactivation of a previously dormant infection acquired outside of the US at least 9 months prior to developing clinical symptoms.

Parasitic central nervous system infections in immunocompromised hosts: malaria, microsporidiosis, leishmaniasis, and African trypanosomiasis

Immunosuppression associated with HIV infection or following transplantation increases susceptibility to central nervous system (CNS) infections. Because of increasing international travel, parasites that were previously limited to tropical regions pose an increasing infectious threat to populations at risk for acquiring opportunistic infection, especially people with HIV infection or individuals who have received a solid organ or bone marrow transplant. Although long-term immunosuppression caused by medications such as prednisone likely also increases the risk for acquiring infection and for developing CNS manifestations, little published information is available to support this hypothesis. In an earlier article published in Clinical Infectious Diseases, we described the neurologic manifestations of some of the more common parasitic CNS infections. This review will discuss the presentation, diagnosis, and treatment of the following additional parasitic CNS infections: malaria, microsporidiosis, leishmaniasis, and African trypanosomiasis.

Visceral leishmaniasis in organ transplant recipients: 11 new cases and a review of the literature

Eleven new cases of visceral leishmaniasis (VL) are reported in organ transplant patients in France. The epidemiological, clinical, biological, diagnostic and therapeutic features are reviewed, based on these cases and 46 cases reported in the literature. VL was most commonly associated with renal transplantation (77% of the cases). Most patients were from Southern European countries. The main clinical symptom was fever. Leucopoenia and anaemia were the most frequent haematological disorders. Diagnosis was by direct finding of the parasite in smears of bone marrow (85.2%) or, by positive serology (90.9%). Without antileishmanial treatment, VL in transplant recipients was fatal. Treatment using either antimonials or amphotericine B gave similar cure rates of around 80% of the cases. But toxicity was higher for antimonials. Relapses occurred in 14.3%.

Visceral leishmaniasis in immunocompromised patients with and without AIDS: a comparison of clinical features and prognosis

Visceral leishmaniasis is basically a disease of healthy infants and adults. However, in the last decade an increasing number of cases of kala azar in immunocompromised patients have been reported with emphasis on atypical manifestations of the disease. During a period of 11 years, 20 immunocompromised patients with AIDS (12 patient), haematological neoplasia (3 patients), corticosteroid therapy (3 patients) or renal transplantation (2 patients) were studied by one or more of the authors. We did not find differences in the presentation of leishmaniasis between patient with or without AIDS and most patients had fever, enlargement of the liver and spleen, blood cytopenias and biochemical abnormalities. Serology was more frequently positive in HIV-negative than in HIV-positive patients (100% versus 63.6%; P=0.13). Bone marrow biopsy was diagnostic in 66% and 87% of patients with and without AIDS, respectively. Failure of anti-leishmanial therapy occurred in 6 of 19 patients treated (31.5%), and 3 patients with AIDS and another 3 without AIDS died during the first episode of leishmaniasis. Of 12 survivors, relapses occurred in five (41.6%). Only patients in whom immunosuppression was ameliorated by means of antiretroviral therapy or by reduction of corticosteroid and other immunosuppressive drugs did not relapse. Treatment of kala azar in immunocompromised host is in satisfactory and new drugs or strategies are urgently needed.

Recurrent cytomegalovirus disease, visceral leishmaniosis, and Legionella pneumonia after liver transplantation: a case report

PURPOSE

Recurrent cytomegalovirus (CMV) disease is a frequent complication of liver transplantation. Visceral leishmaniosis in a transplant recipient is, on the other hand, extremely rare and only two cases of kala-azar have been described after liver transplantation. Immunosuppressed patients are known to be at risk of Legionella infection and the relationship between infection with this organism and hospital water supplies has been well described. These three diseases carry a high mortality rate. Our report examines the potential relationship between these complications.

CLINICAL FEATURES

We describe the case of a liver transplant recipient who presented the three complications successively and survived. After reviewing the literature, we explore hypotheses linking these infections and discuss treatment strategies.

CONCLUSIONS

In the patient described, infection with leishmania probably occurred months prior to the clinical presentation, a delay that matches the incubation period of kala-azar. The simultaneous onset of leishmaniosis and of a high CMV viremia may have been a coincidence. However, CMV infection has been shown to be an independent predictor of invasive fungal infection in liver transplant recipients. CMV does indeed have a suppressive effect on the humoral and cellular immune response in vitro as well as in vivo. The clinical manifestations of leishmaniosis may, therefore, have been precipitated in this patient by the additive immunosuppressive effect of antirejection drugs and CMV.

Visceral leishmaniasis in lung transplantation

Infection by intracellular microorganisms with a special geographic distribution, such as Leishmania spp, has been reported in a limited number of patients undergoing solid-organ transplant (SOT). No cases of Leishmania spp infection in lung transplant patients were found in a review of the literature. In our series of 222 lung or heart and lung transplantations performed from February 1990 to October 2002, two cases of visceral leishmaniasis (VL) were diagnosed and treated with liposomal amphotericin B. All cases reported to date in transplant patients, including the ones discussed here, occurred in people living in or traveling to countries in the Mediterranean area. We therefore consider it advisable to include serological testing for latent infection due to Leishmania spp in pretransplantation screening for our geographical setting, despite the limited return of this strategy.

Antileishmanial drug development: exploitation of parasite heme dependency

A rational approach in the search for new antiparasitic drugs is the exploitation of biochemical differences between the parasite and its mammalian host. One specific example in the case of Leishmania relates to the biosynthesis of heme, a critical prosthetic group for proteins involved in metabolism and electron transport. Like all Trypanosomatids, Leishmania parasites require heme or pre-formed porphyrins for survival because they lack several key enzymes in the heme biosynthetic pathway. Considering their specific nutritional requirements, we speculated that they would be particularly sensitive to the effects of heme-complexing xanthones. In this report, we document the antileishmanial activity of selected nitrogenated xanthones and correlate drug potency with heme affinity. In vitro tests demonstrated that 3,6-bis-omega-diethylaminoamyloxyxanthone, C5, was at least 100 times more active than pentamidine against intracellular amastigotes of Leishmania mexicana. Our findings provide practical guidance for optimizing the antileishmanial activity of the xanthone pharmacophore to better exploit parasite heme salvage processes.

Posttransplant infections in the tropical countries

Over half of all renal transplant recipients in the tropical countries develop a serious infection at some point in the posttransplant period and 20% to 40% of them succumb to these infections. Many of these infections are endemic to the region. A multitude of factors including unhygienic conditions, hot and humid climate, late presentation, lack of knowledge about the spectrum of organisms in these areas, scanty diagnostic techniques, and high cost of lifesaving antimicrobial agents contribute to this dismal outcome. Tuberculosis is observed in 10% to 15% of transplant recipients. Pleuropulmonary disease is most frequent, but the commonly employed tests are seldom helpful in the diagnosis. Bronchoalveolar lavage is very sensitive in early detection of this infection and allows timely institution of specific therapy. Hepatitis virus infections are generally acquired before transplant, and viral replication is accelerated under the effect of immunosuppressive therapy leading to chronic liver disease. Cytomegalovirus (CMV) disease has shown a fourfold increase after introduction of cyclosporine to the immunosuppressive regimes at our center. Coinfection with other bacteria or fungi is frequent in CMV-infected allograft recipients. Opportunistic fungal infections are seen in less than 10% of allograft recipients, but this figure is likely an underestimate. The frequently encountered fungal infections include Candida, Aspergillus, Cryptococcus, and Mucor. Fungal infections carried a high mortality of over 65% at our center. The protean manifestations of the opportunistic infections and nonavailability of sensitive diagnostic tests in most centers in the underdeveloped countries often delay the diagnosis and institution of therapy.

Concurrent cutaneous, visceral and ocular leishmaniasis caused by Leishmania (Viannia) braziliensis in a kidney transplant patient

Although cases of leishmaniasis co-infection have been described in acquired immunodeficiency syndrome patients as well as those who have undergone organ transplants, to our knowledge, the present report is the first documented case of simultaneous cutaneous, visceral and ocular leishmaniasis due to Leishmania (Viannia) braziliensis in a transplant patient. The patient had been using immunosuppressive drugs since receiving a transplanted kidney. The first clinical signs of leishmaniasis included fever, thoracic pain, hepatosplenomegaly, leucopenia and anemia. The cutaneous disease was revealed by the presence of amastigotes in the skin biopsy. After three months, the patient presented fever with conjunctive hyperemia, intense ocular pain and low visual acuity. Parasites isolated from iliac crest, aqueous humor and vitreous body were examined using a range of molecular techniques. The same strain of L. (V.) braziliensis was responsible for the different clinical manifestations. The immunosuppressive drugs probably contributed to the dissemination of Leishmania.

Light microscopic and electron microscopic diagnosis of gastrointestinal opportunistic infections in HIV-positive patients

The surgical pathologist is expected to recognise gastrointestinal opportunistic infections in biopsies from HIV-positive patients, and patients immunocompromised iatrogenically by cancer therapy, steroid treatment and transplantation immunosuppression regimes. This review article presents the diagnostic features in gastrointestinal biopsies of microsporidia, cyclospora, isospora, cryptosporidia, mycobacteria, adenovirus, enteropathogenic bacteria, cryptococcus and leishmania. All of these infections have been diagnosed at our hospital in Sydney, Australia, since the AIDS epidemic began. A protocol for the examination and assessment of these gastrointestinal biopsies is presented and discussed.

Infections in recipients of kidney transplants

A review of infections in kidney transplant recipients is presented in this article, beginning with a discussion of the pretransplant infectious diseases evaluation and an overview of the timing of infectious posttransplant, and then focusing on individual types of infection.

Treatment of visceral leishmaniasis (kala-azar): a decade of progress and future approaches

In 1990, there was essentially one treatment regimen in use for visceral leishmaniasis (kala-azar) around the world: 20 to 28 days of daily injections of pentavalent antimony (Sb). During the past 10 years, however, new agents have been tested alone or in combination, in more than 50 studies carried out worldwide. This renewed clinical effort was spurred by a variety of factors, including the emergence of large-scale Sb unresponsiveness in India, where up to one-half of the world's cases of kala-azar now are found. As this new decade opens, the success of this clinical research effort is tangible: three additional, highly effective parenteral regimens now are available (amphotericin B, lipid formulations of amphotericin B, aminosidine), and an active oral agent, a long sought after objective in kala-azar, has been identified (miltefosine). This report reviews the evolution of treatment of visceral leishmaniasis, considers the interaction of the immune response and chemotherapy, highlights therapeutic successes and failures, examines advantages and disadvantages of current treatments, and looks at future therapeutic approaches to the management of this disseminated intracellular protozoal infection.