Radiological evolution of porcine neurocysticercosis after combined antiparasitic treatment with praziquantel and albendazole

Neurocysticercosis and hydrocephalus: the value of ventriculoperitoneal shunting in its management

BACKGROUND

Hydrocephalus is the main complication of extraparenchymal neurocysticercosis (EP-NC). Its symptomatic management relies mainly on the placement of a ventriculoperitoneal shunt (VPS). Previous studies have shown that this surgical procedure is associated with a poor prognosis, but current information is lacking.

METHODS

We included 108 patients with a definitive diagnosis of EP-NC and hydrocephalus requiring VPS placement. We evaluated their demographic, clinical, and inflammatory characteristics, as well as the frequency of complications related to VPS placement.

RESULTS

Hydrocephalus was present at the time of NC diagnosis in 79.6% of patients. VPS dysfunction occurred in 48 patients (44.4%), mainly within the first year after placement (66.7%). The dysfunctions were not associated with the location of the cyst, the inflammatory characteristics of the cerebrospinal fluid or the administration of cysticidal treatment. They were significantly more frequent in patients in whom the decision to place a VPS was made in the emergency department. Two years after VPS, patients' Karnofsky score averaged 84.6±15 and only one patient died of a cause directly related to VPS.

CONCLUSIONS

This study confirmed the utility of VPS and showed a significant improvement in the prognosis of patients requiring VPS compared with previous studies.

Low responsiveness of peripheral lymphocytes in extraparenchymal neurocysticercosis

BACKGROUND

The morbidity and mortality of extraparenchymal neurocysticercosis (EP-NC) remain high and effectiveness of current medical treatment is suboptimal. Various factors have been implicated in the severity of EP-NC and in the poor response to treatment, but the possible role of host immune and endocrine systems has not yet been examined thoroughly.

METHODOLOGY/PRINCIPAL FINDINGS

42 participants with EP-NC before receiving standard treatment and 25 healthy controls were included in the study. Treatment response was assessed by comparing pre/post treatment parasite volumes from 3D MRI. Prior to treatment among participants with EP-NC, specific stimulation induced an increased specific proliferative response accompanied by a significant increase in IL-4, NK, NKT, Bregs and Tregs cells, whereas in healthy controls, specific stimulation induced a significant increase in IL-1β, IL-5, CCL5, IL-6, TNF-α, NK and Bregs cells. Significant differences between participants with EP-NC and healthy controls in the specific inflammatory response were observed. Participants with EP-NC prior to treatment had significantly weaker responses of proinflammatory cytokines (IL-6, TNF-α) and NK cells, and stronger IL-4 response. Anthelmintic treatment did not promote significant peripheral immunological changes at any time, although inflammation was sustained in the cerebrospinal fluid. Serum estradiol concentration significantly decreased after anthelmintic treatment among males, and cortisol correlated negatively with IL-6 and positively with IFN-γ levels. No pre-treatment immunologic or endocrinologic parameters were significantly associated with response to treatment.

CONCLUSION/SIGNIFICANCE

Prior to anthelmintic treatment, EP-NC was characterized by low lymphocyte reactivity accompanied by a regulatory response, which may be involved in the lack of peripheral immunological changes during and after treatment, although a central inflammatory response was present. This weak specific peripheral response could favor the chronicity of the infection and the poor response to treatment. Our findings highlight the need for new anti-inflammatory treatment focused on the central nervous system with less systemic immunosuppressive effects.

Porcine model of neurocysticercosis by intracarotid injection of Taenia solium oncospheres: Dose assessment, infection outcomes and serological responses

BACKGROUND

Neurocysticercosis (NCC) is the infection of the human central nervous system (CNS) by Taenia solium larvae that cause significant neurological morbidity. Studies on NCC pathophysiology, host-parasite interactions or therapeutic agents are limited by the lack of suitable animal models. We have previously reported that carotid injection of activated T. solium oncospheres directs parasites into the CNS and consistently reproduces NCC. This study assessed the minimal dose required to consistently obtain NCC by intracarotid oncosphere injection and compared antigen and antibody response profiles by dose-group.

METHODS/PRINCIPAL FINDINGS

Three groups of pigs were infected with either 2500 (n = 10), 5000 (n = 11), or 10000 (n = 10) oncospheres. Two pigs died during the study. Necropsy exam at day 150 post-infection (PI) demonstrated viable NCC in 21/29 pigs (72.4%), with higher NCC rates with increasing oncosphere doses (4/9 [44.4%], 9/11 [81.8%] and 8/9 [88.9%] for 2500, 5000, and 10000 oncospheres respectively, P for trend = 0.035). CNS cyst burden was also higher in pigs with increasing doses (P for trend = 0.008). Viable and degenerated muscle cysticerci were also found in all pigs, with degenerated cysticerci more frequent in the 2500 oncosphere dose-group. All pigs were positive for circulating parasite antigens on ELISA (Ag-ELISA) from day 14 PI; circulating antigens markedly increased at day 30 PI and remained high with plateau levels in pigs infected with either 5000 or 10000 oncospheres, but not in pigs infected with 2500 oncospheres. Specific antibodies appeared at day 30 PI and were not different between dose-groups.

CONCLUSION/SIGNIFICANCE

Intracarotid injection of 5000 or more oncospheres produces high NCC rates in pigs with CNS cyst burdens like those usually found in human NCC, making this model appropriate for studies on the pathogenesis of NCC and the effects of antiparasitic treatment.

Efficacy of Combination Therapy of Albendazole and Praziquantel vs Albendazole Monotherapy in Children With Persistent Neurocysticercosis: A Randomized Controlled Trial

AIM

To compare the efficacy of combined albendazole and praziquantel therapy vs albendazole monotherapy in a placebo-controlled, double-blinded, randomized trial in children with persisting neurocysticercosis.

METHODS

Children with persistent neurocysticercosis were randomized into 3 groups-albendazole (n = 19), albendazole and praziquantel (n = 21), and placebo (n = 20)-for 30 days and followed up at 3 and 6 months for resolution and recurrence of seizures.

RESULTS

Mean age of children was 9.3 ± 2.9 years (range 3-14). At baseline, the majority of lesions were ring-enhancing (70%), colloidal (97%), with scolex (68%) and perilesional-edema (45%), and located in the parietal (58%) lobe. One case each in albendazole and placebo groups had a recurrence of seizure in the first month of treatment. The majority (62%) of children in the combination therapy group showed complete resolution of the persisting lesion at the end of 6 months compared to the albendazole alone group (26.3%, P = .02). Percentage reduction in the lesion's mean area at 6 months was highest in the combination group compared with other groups (P = .006). Rate of calcification was identical in all 3 groups (10%). None of the patients required interruption of therapy.

CONCLUSION

Our study demonstrates the safety and efficacy of albendazole and praziquantel in combination for complete radiologic resolution in children with persistent neurocysticercosis when compared with albendazole monotherapy or placebo. The combination therapy did not result in increased seizure recurrence or adverse drug reaction compared with albendazole monotherapy.

Histopathologic evaluation of experimental murine neurocysticercosis after treatment with albendazole/nitazoxanide combination

Neurocysticercosis (NCC) is the most common helminthic brain infection related to epilepsy. Only albendazole (ABZ) and praziquantel are used in its treatment. The development of new therapeutics has been encouraged. Taenia crassiceps cysticerci intracranial infection is the experimental model used in NCC studies. This study evaluated the histopathology of the brains of BALB/c mice experimentally infected with T. crassiceps cysticerci after the treatment with the ABZ/nitazoxanide (NTZ) combination. Thirty days after the inoculation the mice received an oral single dose of the ABZ/NTZ combination (40 mg kg-1 each). The control groups were treated with: NaCl 0.9%; ABZ or NTZ. The histopathologic evaluation of the brains was performed 24 h after treatment. The ABZ treatment induced discrete mononuclear inflammatory infiltration, meningitis, gliosis, hyperaemia and hippocampus compression; moderate ependimitis and oedema. The NTZ treatment induced accentuated inflammatory infiltration, foamy macrophages, ependimitis, choroiditis, gliosis and hyperaemia and moderate oedema. The ABZ/NTZ combination treatment induced a significant decrease in the polymorphonuclear inflammatory infiltration, ependimitis, choroiditis, gliosis, hyperaemia and ventriculomegaly in comparison with the other groups. The cysticerci showed destruction of the tegument not observed in other groups. The ABZ/NTZ combination is efficient as the parasite showed signs of destruction and lower damage to the host's tissue.

A Large Cohort of Neurocysticercosis in Shandong Province, Eastern China, 1997-2015

Neurocysticercosis (NCC) has a wide spectrum of neurologic and psychiatric manifestations, including epileptic seizures, high intracranial pressure, cognitive dysfunction, and meningoencephalitis. This study presents the clinical diagnosis of 2539 NCC patients in Shandong Province, Eastern China, from 1997 to 2015. The diagnosis was based primarily on clinical features, neuroimaging, immunology, and electroencephalogramy studies. In all age groups, seizures were found to be the most common manifestation, followed by headaches, memory loss, and limb numbness, and disability. After antiparasitic treatment, computed tomography and magnetic resonance imaging showed that most of the lesions had been completely absorbed in 2106 (82.95%) patients, most of the lesions had been absorbed and a small proportion was converted into calcifications in 433 (17.05%) cases. Indirect hemagglutination (IHA), enzyme-linked immunosorbent assay (ELISA), and circulating antigen (CAg) serum tests initially gave 76.45%, 86.37%, and 80.66% positive results, respectively. After antiparasitic therapy, the positive rates of the IHA, ELISA, and CAg tests were 74.77%, 84.70%, and 3.75%, respectively, showing no significant difference in antibody levels (p > 0.05), but a significant difference in CAg levels (p < 0.01). The clinical antiparasitic treatment of NCC with three to four courses of a combination of albendazole and praziquantel achieved satisfactory therapeutic efficacy.

MicroRNAs in Taenia solium Neurocysticercosis: Insights as Promising Agents in Host-Parasite Interaction and Their Potential as Biomarkers

MicroRNAs (miRNAs) are short, endogenous, non-coding, single-stranded RNAs involved in post-transcriptional gene regulation. Although, several miRNAs have been identified in parasitic helminths, there is little information about their identification and function in Taenia. Furthermore, the impact of miRNAs in neurocysticercosis, the brain infection caused by larvae of Taenia solium is still unknown. During chronic infection, T. solium may activate numerous mechanisms aimed to modulate host immune responses. Helminthic miRNAs might also have effects on host mRNA expression and thus play an important role regulating host-parasite interactions. Also, the diagnosis of this disease is difficult and it usually requires neuroimaging and confirmatory serology. Since miRNAs are stable when released, they can be detected in body fluids and therefore have potential to diagnose infection, determine parasite burden, and ascertain effectiveness of treatment or disease progression, for instance. This review discusses the potential roles of miRNAs in T. solium infection, including regulation of host-parasite relationships and their eventual use as diagnostic or disease biomarkers. Additionally, we summarize the bioinformatics resources available for identification of T. solium miRNAs and prediction of their targets.