B-Cell Responses in Chronic Chagas Disease: Waning of Trypanosoma cruzi-Specific Antibody-Secreting Cells Following Successful Etiological Treatment.

BACKGROUND: A drawback in the treatment of chronic Chagas disease (American trypanosomiasis) is the long time required to achieve complete loss of serological reactivity, the standard for determining treatment efficacy. METHODS: Antibody-secreting cells and memory B cells specific for Trypanosoma cruzi and their degree of differentiation were evaluated in adult and pediatric study participants with chronic Chagas disease before and after etiological treatment. RESULTS: T. cruzi-specific antibody-secreting cells disappeared from the circulation in benznidazole or nifurtimox-treated participants with declining parasite-specific antibody levels after treatment, whereas B cells in most participants with unaltered antibody levels were low before treatment and did not change after treatment. The timing of the decay in parasite-specific antibody-secreting B cells was similar to that in parasite-specific antibodies, as measured by a Luminex-based assay, but preceded the decay in antibody levels detected by conventional serology. The phenotype of total B cells returned to a noninfection profile after successful treatment. CONCLUSIONS: T. cruzi-specific antibodies in the circulation of chronically T. cruzi-infected study participants likely derive from both antigen-driven plasmablasts, which disappear after successful treatment, and long-lived plasma cells, which persist and account for the low frequency and long course to complete seronegative conversion in successfully treated participants.

Efficacy of continuous versus intermittent administration of nanoformulated benznidazole during the chronic phase of Trypanosoma cruzi Nicaragua infection in mice.

BACKGROUND: Benznidazole and nifurtimox are effective drugs used to treat Chagas' disease; however, their administration in patients in the chronic phase of the disease is still limited, mainly due to their limited efficacy in the later chronic stage of the disease and to the adverse effects related to these drugs. OBJECTIVES: To evaluate the effect of low doses of nanoformulated benznidazole using a chronic model of Trypanosoma cruzi Nicaragua infection in C57BL/6J mice. METHODS: Nanoformulations were administered in two different schemes: one daily dose for 30 days or one dose every 7 days, 13 times. RESULTS: Both treatment schemes showed promising outcomes, such as the elimination of parasitaemia, a reduction in the levels of T. cruzi-specific antibodies and a reduction in T. cruzi-specific IFN-γ-producing cells, as well as an improvement in electrocardiographic alterations and a reduction in inflammation and fibrosis in the heart compared with untreated T. cruzi-infected animals. These results were also compared with those from our previous work on benznidazole administration, which was shown to be effective in the same chronic model. CONCLUSIONS: In this experimental model, intermittently administered benznidazole nanoformulations were as effective as those administered continuously; however, the total dose administered in the intermittent scheme was lower, indicating a promising therapeutic approach to Chagas' disease.

Ultrasound-guided hyaluronic acid injection in carpometacarpal osteoarthritis: short-term results.

Carpometacarpal osteoarthritis (CMC-OA) is a disabling condition, characterized by pain and functional impairment. The aim of the present study is to evaluate the efficacy of a single ultrasoundguided injection of hyaluronic acid (HA) in patients suffering from CMC-OA. Eighteen patients with CMC-OA, grade 2-3 Kellgren and Lawrence score, attending the Orthopaedic Department of the University Hospital of Chieti, were enrolled. They underwent clinical evaluation at baseline and after one month follow-up, evaluating: grading of pain (VAS at rest and during activities), function (Dreiser Index), grip and pinch strengths Jamar dynamometer), as well as NSAIDs consumption. Each patient received a single ultrasound- guided injection of HA into the articular CMC joint. The results were that pain at rest and during activities decreased from 1.8 +/= 1.07 to 0.5 +/= 0.68 (p < 0.001) and from 8.05 +/= 0.94 to 4.15 +/= 1.42 (p < 0.001), respectively. Dreiser Functional Index showed a significant improvement (+11.59 percent; p < 0.004), as well as pulp pinch strength (24.07 percent; p < 0.001). The consumption of NSAIDs was also clearly reduced, from 16 to 7 patients (-45 percent) and from 2.45 +/= 1.98 to 1.15 +/= 1.30 tablets per week (p < 0.02). Mild local side effects, lasting less than 3 hours, were observed only in 2 cases. A single ultrasound guided injection of HA is a safe and effective procedure in CMC-OA, with a significant improvement in terms of pain and function. However, studies with larger samples and longer term follow-up are warranted.