Biomarkers in Post-kala-azar Dermal Leishmaniasis.

Eduard E Zijlstra

doi:10.3389/fcimb.2019.00228

Abstract

Post-kala-azar dermal leishmaniasis (PKDL) follows visceral leishmaniasis (VL, kala-azar) in 10–60% of cases. It is characterized by an asymptomatic skin rash, usually starting in the face and consisting of macules, papules, or nodules. Diagnosis is difficult in the field and is often made clinically. There is an extensive differential diagnosis, and parasitological confirmation is preferred particularly when drug treatment is considered. The response to treatment is difficult to assess as this may be slow and lesions take long to heal, thus possibly exposing patients unnecessarily to prolonged drug treatment. Biomarkers are needed; these may be parasitological (from microscopy, PCR), serological (from blood, or from the lesion), immunological (from blood, tissue), pathological (from cytology in a smear, histology in a biopsy), repeated clinical assessment (grading, photography), or combinations. In this paper, we will review evidence for currently used biomarkers and discuss promising developments.

Highlights

Visceral leishmaniasis (VL, kala-azar) is most common in Asia (India, Bangladesh, Nepal), East Africa (Sudan, South Sudan, Ethiopia, Kenya, Uganda), where it is caused by Leishmania donovani, and South America (Brazil), where Leishmania infantum is the causative parasite
The presence or absence of systemic symptoms and signs is recorded; in 10% of patients, Post-kala-azar dermal leishmaniasis (PKDL) occurs concomitantly with VL, as evidenced by fever, splenomegaly, hepatomegaly or lymphadenopathy, and poor nutritional status (Zijlstra et al, 2003). This distinction is important as the approach to treatment may be different: in case of suspected concomitant VL, parasitological confirmation needs to be sought and systemic treatment is given, by which the PKDL lesions are treated simultaneously
In a recent study, comparing the slit skin smear technique (SSS) and tissue biopsy, all cases with macular lesions (n = 4) were negative in microscopy, while in papular lesions, 2/17 and 10/20 were positive in microscopy, in SSS and biopsy, respectively; for nodular lesions, 13/26 and 20/26 patients were microscopy positive in SSS and biopsy, respectively (Bhargava et al, 2018)

Summary

INTRODUCTION

Visceral leishmaniasis (VL, kala-azar) is most common in Asia (India, Bangladesh, Nepal), East Africa (Sudan, South Sudan, Ethiopia, Kenya, Uganda), where it is caused by Leishmania donovani, and South America (Brazil), where Leishmania infantum is the causative parasite. The presence or absence of systemic symptoms and signs is recorded; in 10% of patients, PKDL occurs concomitantly with VL, as evidenced by fever, splenomegaly, hepatomegaly or lymphadenopathy, and poor nutritional status (para-kala-azar dermal leishmaniasis) (Zijlstra et al, 2003) This distinction is important as the approach to treatment may be different: in case of suspected concomitant VL, parasitological confirmation needs to be sought and systemic treatment is given, by which the PKDL lesions are treated simultaneously. In a recent study, comparing the slit skin smear technique (SSS) and tissue biopsy, all cases with macular lesions (n = 4) were negative in microscopy, while in papular lesions, 2/17 and 10/20 were positive in microscopy, in SSS and biopsy, respectively; for nodular lesions, 13/26 and 20/26 patients were microscopy positive in SSS and biopsy, respectively (Bhargava et al, 2018). Patients who had parasites demonstrated in a lymph node or bone marrow aspirate during PKDL diagnosis had a positive LST in 11%, while those with a negative aspirate were

Method

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DISCUSSION

CONCLUSIONS