Sera of Human Beings Hosting Durably Viscerotropic Leishmania Species Display Histones- Binding Immunoglobulins: A Feature To Consider When Probing Signatures of Auto-Reactivity?

Abstract

When being asked to extract molecular immune signatures, at the preclinical stage of systemic lupus erythematosus (SLE), the analysts who received the subjects' blood, monitor the presence and titers of autoantibodies against a more or less extended panel of SLE associated autoantigens. Tunisian subjects are known to stably share habitats where zoo anthropophilic blood-feeding sand flies and Leishmania infantum co-perpetuate. We were curious to add three other antigenic sources depicted below. Two serum biobanks were selected in the original publication. Analysis from the second shown, four sera containing high titers of mammalian histones autoantibodies as well as a range of ENA-binding autoantibodies. Combined tests that allow detecting antibodies signing [1] risks of developing SLE [2] as well as exposure to viscerotropic Leishmania species, whenever physicians addressed blood of healthy subjects inhabiting areas where perpetuate these species L. chagasi/infantum and L. donovani. L. donovani is the second species within the genus Leishmania to share these so-called viscerotropic features with L. chagasi/infantum.We were not in the position to disentangle the genetic and environmental components that could account for the multiple positive serologic tests in healthy subjects.It will be important to broaden the spectrum of differential diagnoses in healthy subjects at risk of developing auto immune diseases when they stably inhabit areas where sand flies and viscerotropic Leishmania species coperpetuate. Keywords: Systemic Lupus Erythematosus; SLE-associated autoantigen panels; Autoantibodies; Viscerotropic Leishmania species CommentaryIn the publication [1] commented here, the Systemic Lupus Erythematosus (SLE) associated autoantigens were (a) HEp-2 cells substrate with a native protein array with hundreds of antigens, provides an ideal substrate for the detection of ANA allowing the autoantibodies to be detected by Indirect Immunofluorescence (IIF) cell [2]. The detection of ANA in human serum is an important screening tool for SLE, and IIF is the gold method for ANA testing [2].Since the blood samples were collected from Tunisian subjects, we were curious to add three other antigenic sources depicted below to the above mentioned SLE associated autoantigens [3] and (b) human histones rich extracted nuclear auto-antigens (ENA) kits, these autoantibodies being detected and quantified by ELISA.Indeed, Tunisian subjects are known to stably share habitats where zooanthropophilic blood-feeding sand flies and Leishmania/L. infantum co-perpetuate. The completion of the developmental program of the latter eukaryotic single celled parasite is known to proceed through blood-feeding sand flies and mammals such as dogs and human beings [4][5][6].Briefly, once deposited, in the upper dermis, by the sand fly over its blood meal, the mammal pre-adapted L. infantum population of metacyclic promastigotes are rapidly internalized by mononuclear phagocytes/macrophages and dendritic cells.