Efficacy and safety of antiparasitic therapy for neurocysticercosis in rural Tanzania: a prospective cohort study

PURPOSE

Neurocysticercosis is common in regions endemic for Taenia solium. Active-stage neurocysticercosis can be treated with antiparasitic medication, but so far no study on efficacy and safety has been conducted in Africa.

METHODS

We conducted a prospective cohort study on treatment of neurocysticercosis in Tanzania between August 2018 and January 2022. Patients were initially treated with albendazole (15 mg/kg/d) for 10 days and followed up for 6 months. Additionally in July 2021, all participants who then still had cysts were offered a combination therapy consisting of albendazole (15 mg/kg/d) and praziquantel (50 mg/kg/d). Antiparasitic treatment was accompanied by corticosteroid medication and anti-seizure medication if the patient had experienced epileptic seizures before treatment.

RESULTS

Sixty-three patients were recruited for this study, of whom 17 had a complete follow-up after albendazole monotherapy. These patients had a total of 138 cysts at baseline, of which 58 (42%) had disappeared or calcified by the end of follow-up. The median cyst reduction was 40% (interquartile range 11-63%). Frequency of epileptic seizures reduced considerably (p < 0.001). Three patients had all active cysts resolved or calcified and of the remaining 14, eight received the combination therapy which resolved 63 of 66 cysts (95%). Adverse events were infrequent and mild to moderate during both treatment cycles.

CONCLUSION

Cyst resolution was unsatisfactory with albendazole monotherapy but was very high when it was followed by a combination of albendazole and praziquantel.

Functional relevance of NLRP3 inflammasome-mediated interleukin (IL)-1β during acute allergic airway inflammation

Overall asthmatic symptoms can be controlled with diverse therapeutic agents. However, certain symptomatic individuals remain at risk for serious morbidity and mortality, which prompts the identification of novel therapeutic targets and treatment strategies. Thus, using an adjuvant-free T helper type 2 (Th2) murine model, we have deciphered the role of interleukin (IL)-1 signalling during allergic airway inflammation (AAI). Because functional IL-1β depends on inflammasome activation we first studied asthmatic manifestations in specific inflammasome-deficient [NACHT, LRR and PYD domains-containing protein 3 (NLRP3(-/-) ) and apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC(-/-) )] and IL-1 receptor type 1(-/-) (IL-1R1(-/-) ) mice on the BALB/c background. To verify the onset of disease we assessed cellular infiltration in the bronchial regions, lung pathology, airway hyperresponsiveness and ovalbumin (OVA)-specific immune responses. In the absence of NLRP3 inflammasome-mediated IL-1β release all symptoms of AAI were reduced, except OVA-specific immunoglobulin levels. To address whether manipulating IL-1 signalling reduced asthmatic development, we administered the IL-1R antagonist anakinra (Kineret®) during critical immunological time-points: sensitization or challenge. Amelioration of asthmatic symptoms was only observed when anakinra was administered during OVA challenge. Our findings indicate that blocking IL-1 signalling could be a potential complementary therapy for allergic airway inflammation.

Lack of host gut microbiota alters immune responses and intestinal granuloma formation during schistosomiasis

Fatalities from schistosome infections arise due to granulomatous, immune-mediated responses to eggs that become trapped in host tissues. Schistosome-specific immune responses are characterized by initial T helper type 1 (Th1) responses and our previous studies demonstrated that myeloid differentiation primary response gene 88 (Myd88)-deficient mice failed to initiate such responses in vivo. Paradoxically, schistosomal antigens fail to stimulate innate cells to release proinflammatory cytokines in vitro. Since Schistosoma mansoni infection is an intestinal disease, we hypothesized that commensal bacteria could act as bystander activators of the intestinal innate immune system to instigate Th1 responses. Using a broad spectrum of orally administered antibiotics and anti-mycotics we analysed schistosome-infected mice that were simultaneously depleted of gut bacteria. After depletion there was significantly less inflammation in the intestine, which was accompanied by decreased intestinal granuloma development. In contrast, liver pathology remained unaltered. In addition, schistosome-specific immune responses were skewed and faecal egg excretion was diminished. This study demonstrates that host microbiota can act as a third partner in instigating helminth-specific immune responses.