Post Kala-azar Dermal Leishmaniasis (PKDL), a sequel of apparently cured Visceral Leishmaniasis presents in South Asia with papulonodular (polymorphic) or hypomelanotic lesions (macular). Till date, the polymorphic variant was considered predominant, constituting 85-90%. However, following active-case surveillance, the proportion of macular PKDL has increased substantially to nearly 50%, necessitating an in-depth analysis of this variant. Accordingly, this study aimed to delineate the cellular infiltrate in macular vis-à-vis polymorphic PKDL. To study the overall histopathology, hematoxylin and eosin staining was performed on lesional sections and phenotyping by immunohistochemistry done in terms of dendritic cells (CD1a), macrophages (CD68), HLA-DR, T-cells (CD8, CD4), B-cells (CD20) and Ki67 along with assessment of the status of circulating homing markers CCL2, CCL7 and CXCL13. In polymorphic cases (n = 20), the cellular infiltration was substantial, whereas in macular lesions (n = 20) it was mild and patchy with relative sparing of the reticular dermis. Although parasite DNA was identified in both variants by ITS-1 PCR, the parasite load was significantly higher in the polymorphic variant and Leishman-Donovan bodies were notably minimally present in macular cases. Both variants demonstrated a decrease in CD1a+ dendritic cells, HLA-DR expression and CD4+ T-cells. In macular cases, the proportion of CD68+ macrophages, CD8+ T-cells and CD20+ B-cells was 4.6 fold, 17.0 fold and 1.6 fold lower than polymorphic cases. The absence of Ki67 positivity and increased levels of chemoattractants suggested dermal homing of these cellular subsets. Taken together, as compared to the polymorphic variant, patients with macular PKDL demonstrated a lower parasite load along with a lesser degree of cellular infiltration, suggesting differences in host-pathogen interactions, which in turn can impact on their disease transmitting potential and responses to chemotherapy.

中文翻译：

---

多态性与黄斑部印度黑斑病后皮肤利什曼病的原位免疫谱。

黑热病后皮肤利什曼病（PKDL）是一种明显治愈的内脏利什曼病的续集，在南亚地区出现丘疹（多形性）或黑素瘤病（黄斑）。迄今为止，多态性变体被认为是主要的，占85-90％。但是，在进行活动病例监视后，黄斑PKDL的比例已大幅增加至近50％，因此有必要对该变体进行深入分析。因此，本研究旨在描述黄斑区相对于多态性PKDL的细胞浸润情况。为了研究总体组织病理学，对苏木精和伊红染色进行了病灶切片，并通过免疫组织化学对树突状细胞（CD1a），巨噬细胞（CD68），HLA-DR，T细胞（CD8，CD4）进行了表型分析，B细胞（CD20）和Ki67以及循环归巢标记CCL2，CCL7和CXCL13的状态评估。在多态性病例（n = 20）中，细胞浸润是大量的，而在黄斑病变（n = 20）中，它是轻度和斑片状的，且网状真皮相对较少。尽管通过ITS-1 PCR在两种变体中均鉴定出了寄生虫DNA，但在多态性变体中，寄生虫的载量明显更高，在黄斑病例中，利什曼-多诺万体的体显着最少。两种变体均显示CD1a +树突状细胞，HLA-DR表达和CD4 + T细胞减少。在黄斑病例中，CD68 +巨噬细胞，CD8 + T细胞和CD20 + B细胞的比例分别比多态性病例低4.6倍，17.0倍和1.6倍。Ki67阳性的缺乏和趋化剂水平的增加表明这些细胞亚群的皮肤归巢。总之，与多态性变体相比，黄斑型PKDL患者表现出较低的寄生虫负荷以及较低的细胞浸润度，表明宿主-病原体相互作用的差异，进而可能影响其疾病传播潜力和对化学疗法的反应。