Case report: Cutaneous pseudolymphoma caused by a Leishmania infantum infection in a patient treated with anti-TNF antibody for plaque psoriasis

For psoriasis, which affects up to 2% of the population and adalimumab is approved from the age of 4 years. Here, we present a middle-aged Italian man with long-term history of plaque psoriasis and psoriasis arthropathica and adalimumab therapy. He developed ulcers or nodules within the psoriatic plaques, resembling cutaneous infection with Leishmania infantum. TNF and other cytokines such as IL-12 and IFN-γ are central in the early control of the infection. Discontinuation of the anti-TNF-treatment resolved the infection without specific therapy.

Monoclonal Antibodies for Protozoan Infections: A Future Reality or a Utopic Idea?

Following the SARS-CoV-2 pandemic, several clinical trials have been approved for the investigation of the possible use of mAbs, supporting the potential of this technology as a therapeutic approach for infectious diseases. The first monoclonal antibody (mAb), Muromonab CD3, was introduced for the prevention of kidney transplant rejection more than 30 years ago; since then more than 100 mAbs have been approved for therapeutic purposes. Nonetheless, only four mAbs are currently employed for infectious diseases: Palivizumab, for the prevention of respiratory syncytial virus (RSV) infections, Raxibacumab and Obiltoxaximab, for the prophylaxis and treatment against anthrax toxin and Bezlotoxumab, for the prevention of Clostridium difficile recurrence. Protozoan infections are often neglected diseases for which effective and safe chemotherapies are generally missing. In this context, drug resistance and drug toxicity are two crucial problems. The recent advances in bioinformatics, parasite genomics, and biochemistry methodologies are contributing to better understand parasite biology, which is essential to guide the development of new therapies. In this review, we present the efforts that are being made in the evaluation of mAbs for the prevention or treatment of leishmaniasis, Chagas disease, malaria, and toxoplasmosis. Particular emphasis will be placed on the potential strengths and weaknesses of biological treatments in the control of these protozoan diseases that are still affecting hundreds of thousands of people worldwide.

Unusual clinical presentation of cutaneous leishmaniasis in a patient with corticosteroid-induced immunosuppression

Clinicians should always consider rare, atypical, and opportunistic infections in patients undergoing long-term systemic corticosteroid therapy. Diagnosis needs further evaluations and special consideration.

Case Report: Cutaneous Leishmaniasis Misdiagnosed as Pyoderma Gangrenosum

With an estimated prevalence of 0.7%, pyoderma gangrenosum (PG) is the most frequent type of reactive skin lesions seen in the setting of inflammatory bowel disease, together with metastatic Crohn's disease. However, in the case of persistent cutaneous ulcerations in patients with Crohn's disease under biologic and/or immunosuppressive therapy, infectious or malignant etiologies should be excluded. We report a case of multiple difficult-to-treat skin ulcerations due to Leishmania in a patient with Crohn's disease treated with antitumor necrosis factor-alpha drugs, misinterpreted for a long time as PG.

Sonographic findings in visceral leishmaniasis - A narrative review

BACKGROUND

Visceral leishmaniasis (VL) is predominantly a neglected tropical parasitic disease but may also be acquired by travellers. We aimed at summarizing knowledge on sonographic presentation of VL to better understand sonographic features of VL.

METHODS

PubMed was searched for studies and case reports presenting original data on sonographic findings of VL, published before August 13th, 2019. Demographic, clinical, and sonographic data were extracted and summarized in a qualitative approach.

RESULTS

A total of 36 publications were included in this review; 27 of these were case reports and the remainder were prospective or retrospective studies. No study reported systematic cross-sectional comparative imaging. Overall, publications reported on 512 patients with VL of whom 12 were reported HIV-infected. Spleno- and hepatomegaly were the most frequently reported findings. Further relevant and repeatedly reported findings were splenic and hepatic lesions, abdominal lymphadenopathy, pleural and pericardial effusion and ascites. Reported focal splenic lesions were heterogeneous in size, shape, and echogenicity. Several publications reported gradual diminution and resolution of sonographic findings with VL treatment.

CONCLUSION

Available literature on sonographic findings of VL is limited. Available reports indicate that spleno- and hepatomegaly, free fluid, abdominal lymphadenopathy, and focal splenic lesions may be common sonographic features in patients with VL. Because of the apparent overlap of sonographic features of VL, extrapulmonary tuberculosis and other conditions, interpretation of sonographic findings needs to be made with particular caution.

Case Report: Unusual Presentation of Pharyngeal Mucosal Leishmaniasis due to Leishmania (Viannia) braziliensis

Mucosal leishmaniasis (ML) affects predominantly the nose and occurs usually weeks or months after the cure of the primary cutaneous lesion. The pathology of ML is characterized by an exaggerated inflammatory reaction with infiltration of lymphocytes, macrophages, and plasma cells. There is also a paucity of parasites and a strong delayed-type hypersensitivity reaction. Herein, we report a case of a young man who had a large ulcer in his left leg and complained of dysphagia. In nasofibrolaryngoscopy, there were nodular lesions in the oropharynx and rhinopharynx. The skin lesion biopsy showed a chronic inflammation with amastigotes inside macrophages, and DNA of Leishmania braziliensis confirmed the diagnosis of ML in tissue biopsied from the pharynx. The leishmaniasis skin test was negative. Cytokine evaluation showed lack of production of interferon (IFN)-γ, interleukin (IL)-1β, and IL-17 with enhancement of these cytokine levels after cure.

Infectious Complications of Biological and Small Molecule Targeted Immunomodulatory Therapies

The past 2 decades have seen a revolution in our approach to therapeutic immunosuppression. We have moved from relying on broadly active traditional medications, such as prednisolone or methotrexate, toward more specific agents that often target a single receptor, cytokine, or cell type, using monoclonal antibodies, fusion proteins, or targeted small molecules. This change has transformed the treatment of many conditions, including rheumatoid arthritis, cancers, asthma, and inflammatory bowel disease, but along with the benefits have come risks. Contrary to the hope that these more specific agents would have minimal and predictable infectious sequelae, infectious complications have emerged as a major stumbling block for many of these agents. Furthermore, the growing number and complexity of available biologic agents makes it difficult for clinicians to maintain current knowledge, and most review articles focus on a particular target disease or class of agent. In this article, we review the current state of knowledge about infectious complications of biologic and small molecule immunomodulatory agents, aiming to create a single resource relevant to a broad range of clinicians and researchers. For each of 19 classes of agent, we discuss the mechanism of action, the risk and types of infectious complications, and recommendations for prevention of infection.

Leishmania infantum asymptomatic infection in inflammatory bowel disease patients under anti-TNF therapy

BACKGROUND

In recent years anti-TNF therapy has been associated with leishmaniasis in immunocompromised patients from endemic areas. Nevertheless, data on asymptomatic Leishmania infection in such patients is scarce. The aim of this study was to determine the prevalence of asymptomatic infection in inflammatory bowel disease (IBD) patients treated with TNF inhibitors living in an endemic area (Catalonia) and to follow up them to study how the infection evolved.

METHODS

192 IBD patients (143 Crohn's disease; 49 ulcerative colitis) from Catalonia (Spain), an area endemic for L. infantum, were recruited. Peripheral blood samples were collected and tested for anti-Leishmania antibodies by Western blotting (WB). Leishmania kinetoplast DNA was detected in peripheral blood mononuclear cells (PBMC) by a quantitative PCR.

RESULTS

Serology was positive in 3.1% and Leishmania DNA was found in 8.8%, with a low parasitic load and humoral response. The prevalence was 10.9%, patients being considered infected if they tested positive by at least one of the techniques. Eight out of the 21 patients with asymptomatic leishmaniasis were monitored for 3-8 months after the first test. None of them showed an increased parasitemia or humoral response, or developed leishmaniasis during the follow-up period.

CONCLUSION

The prevalence of Leishmania asymptomatic infection detected in our IBD cohort is similar to that found in healthy population in close endemic areas. Due to the short monitoring period, it is not possible to reach a conclusion about the risk of Leishmania reactivation from this study.

Relapsing cutaneous leishmaniasis in a patient requiring TNF-α-inhibitor Infliximab for Takayasu-arteritis: Case report and review of the literature

Leishmaniasis is a protozoan parasitic infection that can manifest as visceral or cutaneous disease. Immunosuppression, mainly through TNF-α) inhibition, is a risk factor for complicated leishmaniasis that is becoming increasingly known. Here, we present a case of cutaneous leishmaniasis (CL) in a patient who suffers from advanced Takayasu-Arteritis, requiring TNF-α inhibition with infliximab. The primary CL lesions in this 47-year-old, female patient were caused by Leishmaniapanamensis and occurred after a touristic trip to Panama on her right foot. The lesions first resolved under treatment with liposomal amphotericin B. However, ten months later, the patient returned with relapsing lesions requiring further treatment. We discuss the challenges and risks of leishmaniasis in patients with TNF-α inhibition and the rare phenomenon of relapsing CL and the management hereof. We review published cases of CL associated with TNF-α inhibition. A growing body of evidence now suggests that especially CL (and visceral leishmaniasis (VL)) can be associated with TNF-α inhibition. The host response to leishmaniasis is of the Th1-type and TNF-α and interferon-gamma expression are crucial for disease control. Inversely, TNF-α inhibition can lead to complicated and relapsing progression of leishmanial infection. Therefore, we propose that CL and VL should be considered in at-risk patients receiving immunosuppressants.

Leishmaniasis and tumor necrosis factor alpha antagonists in the Mediterranean basin. A switch in clinical expression

Background

Tumor necrosis factor alpha (TNF-α) blockers are recognized as a risk factor for reactivation of granulomatous infections. Leishmaniasis has been associated with the use of these drugs, although few cases have been reported.

Methodology

We performed a retrospective observational study including patients with confirmed leishmaniasis acquired in the Mediterranean basin that were under TNF-α blockers therapy at the moment of the diagnosis. Patients diagnosed in our hospital from 2008 to 2018 were included. Moreover, a systematic review of the literature was performed and cases fulfilling the inclusion criteria were also included.

Principal findings

Forty-nine patients were analyzed including nine cases from our series. Twenty-seven (55.1%) cases were male and median age was 55 years. Twenty-five (51%) patients were under infliximab treatment, 20 (40.8%) were receiving adalimumab, 2 (4.1%) etanercept, one (2%) golimumab and one (2%) a non-specified TNF-α blocker. Regarding clinical presentation, 28 (57.1%) presented as cutaneous leishmaniasis (CL), 16 (32.6%) as visceral leishmaniasis (VL) and 5 (10.2%) as mucocutaneous leishmaniasis (MCL). All VL and MCL patients were treated with systemic therapies. Among CL patients, 13 (46.4%) were treated with a systemic drug (11 received L-AmB, one intramuscular antimonials and one miltefosine) while 14 (50%) patients were given local treatment (13 received intralesional pentavalent antimonials, and one excisional surgery). TNF-α blockers were interrupted in 32 patients (65.3%). After treatment 5 patients (10.2%) relapsed. Four patients with a CL (3 initially treated with local therapy maintaining TNF-α blockers and one treated with miltefosine) and one patient with VL treated with L-AmB maintaining TNF-α blockers.

Conclusions

This data supports the assumption that the blockage of TNF-α modifies clinical expression of leishmaniasis in endemic population modulating the expression of the disease leading to atypical presentations. According to the cases reported, the best treatment strategy would be a systemic drug and the discontinuation of the TNF-α blockers therapy until clinical resolution.

Tumor necrosis factor alpha (TNF-α) blockers are widely used in numerous inflammatory diseases such rheumatoid arthritis, psoriasis or inflammatory bowel diseases. They have been recognized as a risk factor for reactivation of granulomatous infections. Although few cases have been reported, Leishmaniasis has been associated with the use of these drugs. Leishmania infantum is the main causative agent of leishmaniasis in Southern Europe and is prone to produce the visceral form. However, TNF-α has been implicated in the initial events of the infection mediating the disease expression. In our series, we have observed a surprisingly high proportion of cutaneous form (32.6%) and muco-cutaneous form (10.2%). Clinical outcome observed in this series is also unusual. Four cases (14.3%) with cutaneous leishmaniasis who received local therapy relapsed. Among patients with visceral leishmaniasis, one patient who maintained TNF-α blockers therapy relapsed despite etiological treatment. This data supports the assumption that the blockage of TNF-α modifies clinical expression of leishmaniasis leading to atypical presentations. According to the cases reported we proposed as best treatment strategy a systemic drug and the discontinuation of the TNF-α blockers therapy until clinical resolution.

Cutaneous, mucocutaneous and visceral leishmaniasis in Sweden from 1996-2016: a retrospective study of clinical characteristics, treatments and outcomes

Background

Leishmaniasis is a neglected and poorly reported parasitic infection transmitted by sand flies in tropical and subtropical regions. Knowledge about leishmaniasis has become important in non-endemic countries due to increased migration and travel. Few studies of the clinical management of cutaneous, mucocutaneous and visceral leishmaniasis in non-endemic regions have been published to date. In this study, we aimed to evaluate patient characteristics, clinical manifestations and treatments of leishmaniasis in Sweden, over a 20-year period.

Methods

A retrospective observational nationwide study was performed using medical records of patients diagnosed with leishmaniasis in Sweden from 1996 to 2016. Cases with culture and polymerase chain reaction verified leishmaniasis were identified at the Public Health Agency of Sweden.

Results

In total, 165 cases of leishmaniasis were diagnosed from 1996 to 2016. Medical records from 156 patients (95%) were available for review and included in the study. Cutaneous leishmaniasis was the dominant manifestation (n = 149, 96%), and in 66 patients (44%) cutaneous leishmaniasis was due to Leishmania tropica. Other manifestations were mucocutaneous (n = 4, 3%), visceral (n = 2, 1%) and post-kala-azar dermal leishmaniasis (n = 1, 1%). During this time period, the number of cases increased, especially after 2013. Most patients (n = 81, 52%) were migrants who were infected in their countries of origin (from 2013 to 2016, mainly Syria or Afghanistan). Other groups were Swedish tourists (25%) and returning workers (13%). The time from collection of the diagnostic sample to the start of treatment was less than one month in 81 (66%) patients and under three months in 124 patients (96%). Among the 149 patients with cutaneous leishmaniasis, 125 patients received antileishmanial treatment, and in 88 of these patients (70%) cure was achieved, regardless of treatment.

Conclusions

The number of leishmaniasis cases diagnosed in Sweden increased between 1996 and 2016, mainly in migrants from endemic countries. Although leishmaniasis is a rare disease in Sweden, patients appear to be diagnosed early and treated according to current European guidelines, resulting in an overall high cure rate.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3539-1) contains supplementary material, which is available to authorized users.

Anti-Tumor Necrosis Factor α Therapeutics Differentially Affect Leishmania Infection of Human Macrophages

Tumor necrosis factor α (TNFα) drives the pathophysiology of human autoimmune diseases and consequently, neutralizing antibodies (Abs) or Ab-derived molecules directed against TNFα are essential therapeutics. As treatment with several TNFα blockers has been reported to entail a higher risk of infectious diseases such as leishmaniasis, we established an in vitro model based on Leishmania-infected human macrophages, co-cultured with autologous T-cells, for the analysis and comparison of anti-TNFα therapeutics. We demonstrate that neutralization of soluble TNFα (sTNFα) by the anti-TNFα Abs Humira^®, Remicade^®, and its biosimilar Remsima^® negatively affects infection as treatment with these agents significantly reduces Leishmania-induced T-cell proliferation and increases the number of infected macrophages. By contrast, we show that blockade of sTNFα by Cimzia^® does not affect T-cell proliferation and infection rates. Moreover, compared to Remicade^®, treatment with Cimzia^® does not impair the expression of cytolytic effector proteins in proliferating T-cells. Our data demonstrate that Cimzia^® supports parasite control through its conjugated polyethylene glycol (PEG) moiety as PEGylation of Remicade^® improves the clearance of intracellular Leishmania. This effect can be linked to complement activation, with levels of complement component C5a being increased upon treatment with Cimzia^® or a PEGylated form of Remicade^®. Taken together, we provide an in vitro model of human leishmaniasis that allows direct comparison of different anti-TNFα agents. Our results enhance the understanding of the efficacy and adverse effects of TNFα blockers and they contribute to evaluate anti-TNFα therapy for patients living in countries with a high prevalence of leishmaniasis.

Cutaneous leishmaniasis associated with TNF-α blockers: a case report

Leishmaniasis is a chronic protozoan disease that is found in diverse geographical areas of the world. Leishmania spp. are endemic in the Mediterranean coasts of southern Europe. Tumour necrosis factor alpha (TNF-α) plays an important role in the defence of the host against infection by Leishmania spp. In this case report we describe Leishmania infection caused by a monoclonal antibody against TNF-α: infliximab. A 51-year-old patient with psoriatic arthritis treated with infliximab, 5 mg/kg every 6 weeks as immunomodulatory treatment and methotrexate 10 mg weekly as a conventional disease-modifying antirheumatic drug, visited his otorhinolaryngologist owing to a lesion in his left nostril. The lesion was diagnosed as cutaneous leishmaniasis so treatment with infliximab was suspended. The patient was then treated with liposomal amphotericin B and showed a total recovery of the lesion; liposomal amphotericin B was maintained at 5 mg/kg monthly.

Case Report: Diffuse Cutaneous Leishmaniasis by Leishmania infantum in a Patient Undergoing Immunosuppressive Therapy: Risk Status in an Endemic Mediterranean Area

This case report highlights the risk of severe cutaneous leishmaniasis (CL) by Leishmania infantum in patients undergoing immunosuppressant therapy who either live in an endemic area or are visiting in the transmission season. The case patient, resident in Majorca (Balearic Islands), presented 12 disseminated erythematous skin lesions, 1-6 cm in diameter, located on the scalp, cheek, umbilical region, and lower extremities 8 years after undergoing anti-tumor necrosis factor (TNF) therapy. Parasite presence in peripheral blood and high levels of specific antibodies were also observed, indicating a possible risk of CL shifting toward a visceral infection. However, once CL was diagnosed, anti-TNF therapy was discontinued and liposomal amphotericin B was administered, resulting in a complete healing of lesions, no Leishmania DNA detection in blood, and an important serological decrease in antibodies. The lack of data on the supposed epidemiological association between leishmaniasis and immunosuppressive therapy highlights the importance of implementing surveillance systems in endemic areas. No obvious relationship was found based on the data provided by the Balearic Islands Epidemiological System, in contrast with data reported in nearby endemic areas. This indicates that if the suspected association is to be clarified, greater efforts are needed to report information about concomitant diseases and therapies in leishmaniasis patients.

Visceral leishmaniosis in immunocompromised host: an update and literature review

Visceral leishmaniasis (VL) is a chronic infectious disease endemic in tropical and sub-tropical areas including the Mediterranean basin, caused by a group of protozoan parasites of the genus Leishmania and transmitted by phlebotomine sandflies. Immunocompromised patients, in particular HIV positive, are considered at risk of VL. They report atypical signs and poor response to treatment due to impairment of T-helper and regulatory cells activity. Laboratory diagnosis is based on microscopy on bone marrow or spleen aspirates. Value of serology remains high in term of sensibility, but a positive test must be confirmed by microscopy or molecular tests. Treatment is based on Liposomal amphotericin B whose administration is associated to lower incidence of side effects, in respect to antimonials and other formulations of AmB. Use of Miltefosine needs further investigation when L. infantum is the causative agent. Frequent relapses are observed in co-infected HIV who can benefit of a second cycle.

Reactivation of cutaneous and mucocutaneous tegumentary leishmaniasis in rheumatoid arthritis patients: an emerging problem?

Rheumatoid arthritis (RA) is a chronic condition that is frequent in patients living in tropical areas exposed to leishmaniasis. RA therapy involves immunosuppressant drugs such as methotrexate (MTX), monoclonal antibodies (mAbs) and prednisone. We report an unusual presentation of cutaneous (CL) or mucocutaneous leishmaniasis (ML) in RA patients from an endemic area of leishmaniasis. A 51-year-old woman noted a cutaneous ulcer on her left ankle during MTX and prednisone RA therapy. Initially diagnosed as a venous stasis ulcer, the aspirate of the injury revealed the presence of Leishmania DNA. A 73-year-old woman presenting non-ulcerated, infiltrated and painful erythematous nodules inside her nostrils while receiving MTX, anti-TNF mAb, and prednisone for RA, had also the aspirate of injuries showing the presence of Leishmania DNA. Both patients healed after the therapy with liposomal amphotericin. The RA therapy has changed to low-dose prednisone, without further reactivation episodes. Both cases suggest that CL or ML can reactivate after administration of an immunosuppressant for RA treatment. Therefore, immunosuppressive treatments for RA should be carefully prescribed in patients from endemic areas or with a history of CL and ML.

Evolution of cutaneous leishmaniasis in the last 30 years in a tertiary hospital of the European Mediterranean coast

BACKGROUND

Although with a lower incidence than in other geographic areas, leishmaniasis is also endemic on the European Mediterranean coast. However, there are few studies on the clinical features of cutaneous lesions of leishmaniasis in Europe. Our objective was to review the clinical features of cutaneous leishmanial lesions in our European Mediterranean population in the last 30 years and compare the clinical features of immunosuppressed and nonimmunosuppressed patients.

METHODS

The clinical features of cutaneous lesions of leishmaniasis diagnosed between 1987 and 2016 at Bellvitge Hospital in Barcelona, Spain, were retrospectively analyzed.

RESULTS

Cutaneous lesions of leishmaniasis were diagnosed in 68 patients (40 male and 28 female, mean age 53.60 years, SD 19.68). Thirteen patients were immunosuppressed because of acquired immune deficiency syndrome (AIDS) (7), renal transplantation (1), lymphoma (1), and anti-TNF agents (4). Our immunosuppressed patients had more lesions (3.33 vs. 1.80, P = 0.021), with greater maximum diameter (33.00 vs. 13.33 mm, P = 0.001), and their lesions were more frequently disseminated (P = 0.008). Visceral leishmaniasis was observed only in immunosuppressed patients. Patients treated with anti-TNF drugs developed unusually large skin lesions with crusted, eroded surfaces and without a tendency to spontaneous remission.

CONCLUSION

With the widespread use of anti-TNF agents, an increase in severe forms of leishmaniasis can be expected. The development of persistent, crusted, or eroded erythematous-brownish plaques in patients treated with anti-TNF drugs who live or had traveled to endemic areas of Leishmania infection warrants consideration of a diagnosis of cutaneous leishmaniasis.

Cutaneous leishmaniasis associated with anti-tumour necrosis factor-α drugs: an emerging disease

Leishmaniasis is endemic in several geographic areas of the world. In each of these areas, particular species of Leishmania with differing aggressiveness to humans predominate. In the European Mediterranean basin, cutaneous leishmaniasis usually presents with discrete, self-healing skin lesions. Although it is known that tumour necrosis factor (TNF) inhibitors may increase the risk of developing infections such as tuberculosis, there is scarce literature on Leishmania infections in patients treated with these drugs. In recent months, we have observed three patients resident in the Catalan coast of Spain who were treated with TNF inhibitors for Crohn disease, and who developed unusually large and persistent cutaneous lesions of leishmaniasis. These lesions responded only to treatment with intravenous liposomal amphotericin B. In countries with a high incidence of infection by aggressive species of Leishmania, serological screening may be indicated to detect a possible latent leishmanial infection before prescription of TNF inhibitors.

Management of infections in critically ill returning travellers in the intensive care unit-II: clinical syndromes and special considerations in immunocompromised patients

This position paper is the second ESCMID Consensus Document on this subject and aims to provide intensivists, infectious disease specialists, and emergency physicians with a standardized approach to the management of serious travel-related infections in the intensive care unit (ICU) or the emergency department. This document is a cooperative effort between members of two European Society of Clinical Microbiology and Infectious Diseases (ESCMID) study groups and was coordinated by Hakan Leblebicioglu and Jordi Rello for ESGITM (ESCMID Study Group for Infections in Travellers and Migrants) and ESGCIP (ESCMID Study Group for Infections in Critically Ill Patients), respectively. A relevant expert on the subject of each section prepared the first draft which was then edited and approved by additional members from both ESCMID study groups. This article summarizes considerations regarding clinical syndromes requiring ICU admission in travellers, covering immunocompromised patients.

Tumor necrosis factor alpha neutralization has no direct effect on parasite burden, but causes impaired IFN-γ production by spleen cells from human visceral leishmaniasis patients

The pro-inflammatory cytokine tumor necrosis factor (TNF)-α has an important role in control of experimental Leishmania donovani infection. Less is known about the role of TNF-α in human visceral leishmaniasis (VL). Evidence for a protective role is primarily based on case reports of VL development in individuals treated with TNF-α neutralizing antibody. In this study, we have evaluated how TNF-α neutralization affects parasite replication and cytokine production in ex vivo splenic aspirates (SA) from active VL patients. The effect of TNF-α neutralization on cell mediated antigen specific responses were also evaluated using whole blood cultures. Neutralization of TNF-α did not affect parasite numbers in SA cultures. Interferon (IFN)-γ levels were significantly reduced, but interleukin (IL)-10 levels were unchanged in these cultures. Leishmania antigen stimulated SA produced significant TNF-α which suggests that TNF-α is actively produced in VL spleen. Further it stimulates IFN-γ production, but no direct effect on parasite replication.