First case report of M1 macrophage polarization in an untreated symptomatic patient with toxoplasmosis

Abstract

BackgroundIn immunocompetent patients, acute toxoplasmosis is usually asymptomatic. We identified M1 macrophages in a case of symptomatic acute Toxoplasma gondii infection that resolved without treatment. M1 macrophages have been demonstrated in animal models of toxoplasmosis, but not in humans.Case presentationA 63-year-old woman presented with laterocervical and axillary bilateral lymphadenopathy. Her anamnesis defined an episode of high fever and prolonged asthenia 4 months previously, which suggested an infectious disease. Following laboratory, radiological, and pathological analyses, she was diagnosed with toxoplasmosis. Immunohistochemical analyses were performed on lymph node sections. More than 50% of the macrophages in the lymph node microgranulomas were M1 macrophages, defined by CD68+/p-Stat1+ staining, and the presence of T helper 1 lymphocytes indicated an immune response known to induce M1 macrophage polarization. Activated endothelial cells were found only in inflamed areas. No therapy was administered before or after diagnosis, and the lymphadenopathy resolved after a follow-up of 5 months.ConclusionsThis is the first report to demonstrate the presence of M1 macrophages in human toxoplasmosis. Our findings contribute to the understanding of the pathogenesis of toxoplasmosis, and encourage further studies on the role of macrophage polarization in human toxoplasmosis.

Key Limitations and New Insights Into the Toxoplasma gondii Parasite Stage Switching for Future Vaccine Development in Human, Livestock, and Cats

“…Up-regulation of CD80, CD86, and CD40 on dendritic cells infected with T. gondii, have important implication for the initiation of a T cell response because T cell production of INF-g in response to T. gondii-infected DC is dependent on CD40-CD40L and CD80/CD86-CD28 signaling (Subauste and Wessendarp, 2000). Recently, a morphological and immunohistochemical evaluation of inflammatory cells in axillary lymph nodes from a symptomatic acute toxoplasmosis which self-resolved, demonstrated the presence of M1 macrophages and of T helper 1 lymphocytes (De-Luca et al, 2018).…”

Intervention threshold for epidemic control in susceptible-infected-recovered metapopulation models

“…Metapopulation epidemic models are a class of models that describe epidemic spreading processes in a group of spatially separated patches connected via migration pathways. This framework has been intensively studied to develop analytical methods for global epidemic thresholds [16][17][18][19][20][21][22][23][24][25][26][27][28][29] and widely applied to understanding actual epidemic outbreaks [30][31][32][33][34]. In a metapopulation model, infection and recovery events occur in each patch and migration of individuals potentially causes global epidemic spreading.…”