Efficacy of Intensified Hygiene Measures with or without the Addition of Doxycycline in the Management of Filarial Lymphedema: A Randomized Double-Blind, Placebo-Controlled Clinical Trial in Tanzania.

Lymphedema, hydrocele, and acute adenolymphangitis (ADL) are chronically disabling consequences in patients with lymphatic filariasis (LF). Provision of morbidity management and disability prevention and concurrent mass drug administration of anthelmintics are two pillars for elimination of LF. This study assessed the impact of strict hygiene protocols with or without doxycycline on the progression of filarial lymphedema. A randomized, placebo-controlled, double-blind trial was conducted in two regions in Tanzania. We enrolled 362 participants with lymphedema stages 1-3 assigned into three treatment groups of doxycycline 200 mg once daily, doxycycline 100 mg once daily, or matching placebo for 42 days in addition to hygiene measures. The participants were followed every 2 months for 2 years. Twenty-four months after treatment onset, 17.7% of participants displayed improved limb conditions, including 15/104 (14.4%) in the doxycycline 200 mg group, 16/105 (15.2%) in the doxycycline 100 mg group, and 25/107 (23.4%) in the placebo group. During the first 6 months after treatment, the number of participants experiencing an ADL attack was significantly lower in the doxycycline groups than in the placebo group. The study also found that hygiene was one of the factors associated with preventing the occurrence of acute attacks over the whole study period. Doxycycline 100 mg was a significant factor for the halt of progression (odds ratio: 0.53, P = 0.0239) when both legs if affected at baseline were considered. These findings emphasize the importance of practicing hygiene in reducing the occurrence of ADL attacks and the benefits of doxycycline with regards to acute attacks and halt of progression.

Eosinophils Suppress the Migration of T Cells Into the Brain of Plasmodium berghei-Infected Ifnar1-/- Mice and Protect Them From Experimental Cerebral Malaria.

Cerebral malaria is a potentially lethal disease, which is caused by excessive inflammatory responses to Plasmodium parasites. Here we use a newly developed transgenic Plasmodium berghei ANKA (PbAAma1OVA) parasite that can be used to study parasite-specific T cell responses. Our present study demonstrates that Ifnar1-/- mice, which lack type I interferon receptor-dependent signaling, are protected from experimental cerebral malaria (ECM) when infected with this novel parasite. Although CD8+ T cell responses generated in the spleen are essential for the development of ECM, we measured comparable parasite-specific cytotoxic T cell responses in ECM-protected Ifnar1-/- mice and wild type mice suffering from ECM. Importantly, CD8+ T cells were increased in the spleens of ECM-protected Ifnar1-/- mice and the blood-brain-barrier remained intact. This was associated with elevated splenic levels of CCL5, a T cell and eosinophil chemotactic chemokine, which was mainly produced by eosinophils, and an increase in eosinophil numbers. Depletion of eosinophils enhanced CD8+ T cell infiltration into the brain and increased ECM induction in PbAAma1OVA-infected Ifnar1-/- mice. However, eosinophil-depletion did not reduce the CD8+ T cell population in the spleen or reduce splenic CCL5 concentrations. Our study demonstrates that eosinophils impact CD8+ T cell migration and proliferation during PbAAma1OVA-infection in Ifnar1-/- mice and thereby are contributing to the protection from ECM.