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1.
Am J Trop Med Hyg ; 110(5): 1014-1020, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38531100

ABSTRACT

Anemia is a complex condition associated with diet, chronic infections, and blood loss. Children living at high altitudes have higher absolute hemoglobin levels due to hypoxemia. However, they are exposed to repeated infections and dietary limitations. We conducted a cross-sectional study to identify factors affecting the hemoglobin concentration in children living in high-altitude rural communities in the Anta province of Peru. All children 3-16 years of age attending public schools were invited to participate. We enrolled children 3-16 years old in schools and visited their homes to collect demographic, socioeconomic, medical history, and anthropometric data. Children provided blood and stool samples for complete blood counts, iron status markers, and helminth infection testing. Among the 2,000 children enrolled, the mean age was 9.9 (±3.4) years, 1,004 (50.2%) were female, and the median residence altitude was 3,398 (interquartile range 3,35-3,497) meters. The mean hemoglobin level was 15 (±1.15) mg/dL; 320 (16%) had anemia as defined by WHO. Children with anemia were more likely to have lower serum iron levels (odds ratio [OR] 2.8 [95% CI 2.2-3.6], P <0.001) and serum transferrin saturation (OR 2.8 [95% CI 2-3.9], P <0.001). Younger age (OR 0.85 [95% CI 0.82-0.89], P <0.001), stunting (OR 0.68 [95% CI 0.59-0.79], P <0.001), education of the mother (OR 0.94 [95% CI 0.91-0.98], P <0.005), and low eosinophils (OR 0.49 [95% CI 0.26-0.9], P = 0.022) were associated with anemia. Helminth infections were not associated with anemia. Anemia among children at high altitude is multifactorial, but iron deficiency is a contributing factor. Further studies are needed to evaluate iron status and anemia in children living at high altitudes.


Subject(s)
Altitude , Hemoglobins , Iron , Humans , Peru/epidemiology , Child , Female , Male , Hemoglobins/analysis , Hemoglobins/metabolism , Child, Preschool , Adolescent , Cross-Sectional Studies , Iron/blood , Anemia, Iron-Deficiency/epidemiology , Anemia, Iron-Deficiency/blood , Biomarkers/blood , Anemia/epidemiology , Anemia/blood , Rural Population/statistics & numerical data
2.
Expert Rev Anti Infect Ther ; 21(2): 167-173, 2023 02.
Article in English | MEDLINE | ID: mdl-36533398

ABSTRACT

INTRODUCTION: Cryptosporidiosis was initially recognized as an important cause of diarrhea in AIDS patients. It has been underdiagnosed in other populations. Recent studies have highlighted the importance of Cryptosporidium as a cause of diarrhea and malnutrition in young children in resource-poor countries and an emerging pathogen in organ-transplant recipients. AREAS COVERED: Nitazoxanide is FDA approved for treatment of cryptosporidiosis in immunocompetent people. However, it is less effective in HIV and transplant patients and malnourished children. In transplant recipients, there is emerging data on antiparasitic combinations for cryptosporidiosis, including combinations of nitazoxanide, azithromycin, and in one case rifaximin. High-throughput phenotypic screens have identified some potential treatments. Among them, clofazimine was no better than placebo in a trial in AIDS patients. There have also been efforts to develop drug versus specific parasite targets. However, in part due to safety issues, none of these compounds have advanced into clinical trials. EXPERT OPINION: Development of new and more efficacious therapies for cryptosporidium is imperative. Current approve therapy is far from optimal and lacks efficacy in high-risk populations, such as, patients living with HIV. Additionally, there is limited data on patients with other types of immunosuppression (Transplanted, autoimmune conditions, etc).


Subject(s)
Acquired Immunodeficiency Syndrome , Antiprotozoal Agents , Cryptosporidiosis , Cryptosporidium , Child , Humans , Child, Preschool , Cryptosporidiosis/drug therapy , Cryptosporidiosis/parasitology , Diarrhea/drug therapy
3.
Curr Opin Infect Dis ; 35(3): 246-254, 2022 06 01.
Article in English | MEDLINE | ID: mdl-35665719

ABSTRACT

Neurocysticercosis (NCC) is an important cause of neurological disease worldwide, including imported cases in nonendemic countries. PURPOSE OF REVIEW: The purpose of this review is to update information on diagnosis, management, and prevention of neurocysticercosis. RECENT FINDINGS: WHO and Infectious Diseases Society of America/American Society of Tropical Medicine and Hygiene guidelines emphasize the importance of corticosteroids and antiparasitic drugs for viable parenchymal disease and single enhancing lesions. Subarachnoid NCC is associated with a high fatality rate unless optimally treated. Advances in subarachnoid NCC include use of prolonged antiparasitic and anti-inflammatory courses and the increasing use of antigen-detection and quantitative PCR assays in diagnosis and follow-up. Emerging data support the safety and efficacy of minimally invasive surgery in ventricular cases. Calcified neurocysticercosis continues to be associated with a high burden of disease. Field studies are demonstrating the feasibility of eradication using a combination of mass chemotherapy for human tapeworms and vaccination/treatment of porcine cysticercosis. SUMMARY: NCC remains an important and challenging cause of neurological disease with significant morbidity despite advances in treatment and prevention.


Subject(s)
Neurocysticercosis , Animals , Anti-Inflammatory Agents/therapeutic use , Antiparasitic Agents/therapeutic use , Humans , Hygiene , Neurocysticercosis/diagnosis , Neurocysticercosis/drug therapy , Neurocysticercosis/prevention & control , Subarachnoid Space/pathology , Swine
4.
Open Forum Infect Dis ; 9(1): ofab610, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34993260

ABSTRACT

BACKGROUND: Cryptosporidium is a major cause of diarrheal disease worldwide, including chronic disease in malnourished children and patients with acquired immune deficiency syndrome. There are increasing reports of cryptosporidiosis in transplant patients, especially from middle-income countries. METHODS: The literature on treatment of cryptosporidiosis in transplant patients was reviewed and included no controlled trials but only small case series. Nitazoxanide, azithromycin, spiramycin, and combination therapies have been used, but none are consistently efficacious. RESULTS: We present a case of chronic diarrhea from cryptosporidiosis in a renal transplant patient. His illness resolved with decreasing immunosuppression and treatment with the 3-drug combination of nitazoxanide, azithromycin, and rifaximin. CONCLUSIONS: Although current therapies are not reliably effective in the absence of an effective cellular immune response, combination therapies hold promise for improved responses.

5.
Parasitol Res ; 120(8): 2965-2968, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34245363

ABSTRACT

Fascioliasis is a foodborne trematode endemic worldwide. Children under 15 years have the highest prevalence of infection. We hypothesized that acute fascioliasis would be associated with more pronounced cytokine changes than in chronic disease or no helminth infections. To test this hypothesis, 33 children who lived in the Peruvian highlands were classified into 3 groups: acute fascioliasis, chronic fascioliasis, and no helminth infection. Type Th1, Th2, and Th17 cytokines were measured in plasma by cytometric bead array. Children with acute infection had higher levels of IL-5 and IL-17 compared with controls (p < 0.001 and p < 0.007, respectively). The increased IL-5 plasma concentration in children with acute infection was associated with the eosinophilia found in that group.


Subject(s)
Cytokines/immunology , Fascioliasis/immunology , Animals , Child , Fasciola hepatica , Humans , Interleukin-5 , Peru , Th17 Cells
6.
Am J Trop Med Hyg ; 105(3): 684-687, 2021 07 19.
Article in English | MEDLINE | ID: mdl-34280140

ABSTRACT

School-age children bear the highest burden of fascioliasis in endemic countries. Few studies have addressed Fasciola in preschool children. We performed a secondary data analysis using two Fasciola databases from Cusco, Peru, comparing preschoolers with elementary school children. We included 2,630 children, 50% were female, the median age was 8.4 years (interquartile range [IQR] 6.1-10.5), and 15% (396/2,630) were < 5 years of age. Children < 5 years were less likely to be infected with Fasciola hepatica (P = 0.008) and Hymenolepis nana (P < 0.001) and more likely to have anemia (P < 0.001) and a lower median height for age Z (HAZ) score (P = 0.002). Fascioliasis was less common in younger children, but this group may be at higher risk for chronic complications caused by fascioliasis.


Subject(s)
Fascioliasis/epidemiology , Age Factors , Anemia/epidemiology , Anemia/therapy , Child , Child Nutrition Disorders/epidemiology , Child Nutrition Disorders/therapy , Child, Preschool , Chronic Disease , Databases, Factual , Fascioliasis/physiopathology , Female , Growth Disorders/epidemiology , Humans , Male , Peru/epidemiology , Risk Factors
7.
Emerg Infect Dis ; 27(7): 1850-1857, 2021 07.
Article in English | MEDLINE | ID: mdl-34152949

ABSTRACT

We conducted a retrospective cohort study of children who had chronic fascioliasis in the highlands of Peru to determine triclabendazole treatment efficacy. Children passing Fasciola eggs in stool were offered directly observed triclabendazole treatment (>1 doses of 10 mg/kg). Parasitologic cure was evaluated by using microscopy of stool 1-4 months after each treatment. A total of 146 children who had chronic fascioliasis participated in the study; 53% were female, and the mean ± SD age was 10.4 ± 3.1 years. After the first treatment, 55% of the children achieved parasitologic cure. Cure rates decreased after the second (38%), third (30%), and fourth (23%) treatments; 17 children (11.6%) did not achieve cure after 4 treatments. Higher baseline egg counts and lower socioeconomic status were associated with triclabendazole treatment failure. Decreased triclabendazole efficacy in disease-endemic communities threatens control efforts. Further research on triclabendazole resistance and new drugs to overcome it are urgently needed.


Subject(s)
Anthelmintics , Fasciola hepatica , Fascioliasis , Adolescent , Animals , Anthelmintics/therapeutic use , Child , Child, Preschool , Feces , Female , Humans , Peru , Retrospective Studies , Schools , Treatment Failure , Triclabendazole/therapeutic use
8.
PLoS Negl Trop Dis ; 15(6): e0009519, 2021 06.
Article in English | MEDLINE | ID: mdl-34153050

ABSTRACT

Fascioliasis is a zoonotic trematode infection that is endemic in the highlands of Peru. Chronic fascioliasis can be asymptomatic and remain undiagnosed for years. Chronic malnutrition in children, as manifested by stunting, leads to delayed cognitive development and lost productivity. We hypothesized that fascioliasis is among the factors associated with stunting in children from endemic areas. We conducted a cross-sectional study among children attending pre-school and school in 26 communities in the Anta province in the Cusco region of Peru. We conducted interviews to collect information on demographic, socioeconomic, and medical history. Blood was collected and tested for complete cell count and FAS2 ELISA for Fasciola antibodies. Three stool samples per participant were tested for parasites by Kato-Katz and Lumbreras rapid sedimentation methods. Chronic fascioliasis was determined by the presence of ova in stool. Children's height, weight, and age were recorded and used to calculate height for age Z scores (HAZ). Three thousand children participated in the study. Nine percent (264) of children had at least one positive test for Fasciola infection, 6% (164) had chronic fascioliasis, and 3% (102) had only positive antibody tests. The median HAZ was -1.41 (IQR: -2.03 to -0.81) and was similar in males and females. Twenty six percent (776) of children had stunting with HAZ < -2. Children with chronic fascioliasis had a lower median HAZ than children without Fasciola (-1.54 vs. -1.4, p = 0.014). History of treatment for malnutrition, history of treatment for anemia, having other helminths in stool, lower socioeconomic score, living at a higher elevation, and fewer years of schooling of both parents were associated with a lower HAZ score. In a multiple regression analysis, older age and a lower socioeconomic score were associated with a lower HAZ score. While fascioliasis and other helminths were associated with lower HAZ, they were not independent of the socioeconomic score.


Subject(s)
Fascioliasis/epidemiology , Feces/parasitology , Growth Disorders/epidemiology , Socioeconomic Factors , Adolescent , Altitude , Anemia , Animals , Antibodies, Helminth/blood , Child , Child Nutrition Disorders/epidemiology , Child, Preschool , Cross-Sectional Studies , Fasciola/immunology , Fasciola/isolation & purification , Fascioliasis/immunology , Female , Helminths/isolation & purification , Humans , Male , Peru/epidemiology
9.
Vector Borne Zoonotic Dis ; 21(9): 707-712, 2021 09.
Article in English | MEDLINE | ID: mdl-34129405

ABSTRACT

Fascioliasis is a zoonotic infection linked to significant economic losses in the livestock industry. Infection prevalence and estimated financial burden vary across locations owing to different diagnostic tests used. The accuracy of liver condemnation to estimate the prevalence and costs of fascioliasis has seldom been evaluated. We performed a pilot study to determine the prevalence and burden of Fasciola hepatica infection among cattle slaughtered at the municipal abattoir in the Anta province of the Cusco highlands in Peru. We compared liver condemnation with bile microscopy for the diagnosis of infection and prediction of carcass weight. Data were collected from 2009 slaughtered cattle for 1 year. The overall prevalence of Fasciola infection by bile microscopy was 62.5% (1247/2009). A higher prevalence was observed after the rainy season from March to August than from September to February (p < 0.01). Fascioliasis prevalence during the first 6 months was 77.4% (714/923), combining the results of condemnation and microscopy. Bile microscopy diagnosed more infections than liver condemnation (62.7% (579/923) versus 55.4% (511/923), McNemar test p < 0.01). The agreement of the bile microscopy testing with liver condemnation was fair (κ = 0.247). Animal age, gender, breed, and liver condemnation predicted carcass weight [F (df 4, 704) = 61.1, p < 0.001]. Liver condemnation and bile microscopy are complementary tools for evaluation of the prevalence and burden of fascioliasis in livestock. Large scale studies are warranted to confirm our results.


Subject(s)
Cattle Diseases , Fasciola hepatica , Fascioliasis , Animals , Bile , Cattle , Cattle Diseases/epidemiology , Fascioliasis/epidemiology , Fascioliasis/veterinary , Liver , Microscopy/veterinary , Peru/epidemiology , Pilot Projects , Prevalence
10.
Am J Trop Med Hyg ; 104(6): 2069-2073, 2021 05 03.
Article in English | MEDLINE | ID: mdl-33939646

ABSTRACT

Fasciola hepatica is highly prevalent in the highlands of Peru. School-age children have the greatest risk of infection. Mass treatment of at-risk populations has been proposed to control the infection and prevent complications. However, the decreasing effectiveness of triclabendazole raises concerns regarding this strategy. Previous studies reported aggregation of Fasciola infection among family members. This study aimed to determine the risk of fascioliasis among household members living with Fasciola-infected children identified through school-based testing. We conducted a cross-sectional study including adult members of households where children with and without fascioliasis were identified. Demographic, epidemiological, and socioeconomic information was collected. One blood sample was drawn to test for Fasciola antibodies, and three stool samples were collected for microscopy for Fasciola ova. We tested 326 adults from 213 households. Of these adult subjects, chronic fascioliasis (24 of 326, 7.4%) was the most common helminth infection. Thirty-nine subjects (12.7%) tested positive for Fasciola antibodies. Combining microscopy and serum antibody tests, 13.2% (43 of 326) had evidence of Fasciola infection. One third (104 of 326, 31.9%) of the participants lived with at least one child infected with Fasciola hepatica. Adults with fascioliasis were four times more likely to live with an infected child. Poverty and diet were associated with increased risk of Fasciola infection. Adults with fascioliasis were significantly more likely to live with Fasciola-infected children.


Subject(s)
Family , Fasciola hepatica/immunology , Fascioliasis/epidemiology , Adult , Animals , Antibodies, Helminth/blood , Cross-Sectional Studies , Fasciola hepatica/pathogenicity , Fascioliasis/diagnosis , Feces/parasitology , Female , Humans , Male , Middle Aged , Peru , Prevalence , Risk Factors
11.
PLoS Negl Trop Dis ; 15(3): e0009193, 2021 03.
Article in English | MEDLINE | ID: mdl-33788843

ABSTRACT

Single brain enhancing lesions (SEL) are the most common presentation of neurocysticercosis (NCC) observed on neuroimaging in people presenting with epileptic seizures not only on the Indian sub-continent and in travelers returning from cysticercosis-endemic regions, but are also present in other parts of the world. The aim of this study, which consisted of a systematic review (CRD42019087665), a meta-analysis and an expert group consultation, was to reach consensus on the best anti-seizure medication and anti-inflammatory treatment for individuals with SEL NCC. Standard literature review methods were used. The Cochrane risk of bias tool was used and random effects model meta-analyses were performed. The quality of the body of evidence was rated using GRADE tables. The expert committee included 12 gender and geographically balanced members and recommendations were reached by applying the GRADE framework for guideline development. The 1-1.5-year cumulative incidence of seizure recurrence, cyst resolution or calcification following anti-seizure medication (ASM) withdrawal was not statistically different between ASM of 6, 12 or 24 months. In contrast, in persons whose cyst calcified post treatment, longer ASM decreased seizure recurrence. The cumulative incidence ratio (CIR) 1-1.5 years after stopping ASM was 1.79 95% CI: (1.00, 3.20) for patients given 6 versus 24 months treatment. Anti-inflammatory treatment with corticosteroids in patients treated with ASM compared to patients treated with ASM only showed a statistically significant beneficial effect on seizure reduction (CIR 0.44, 95% CI 0.23, 0.85) and cyst resolution (CIR 1.37, 95%CI: 1.07, 1.75). Our results indicate that ASM in patients with SEL NCC whose cysts resolved can be withdrawn, while patients whose cysts calcified seem to benefit from prolonged anti-seizure medication. Additional corticosteroid treatment was found to have a beneficial effect both on seizure reduction and cyst resolution.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Anticonvulsants/therapeutic use , Neurocysticercosis/complications , Adrenal Cortex Hormones/administration & dosage , Adrenal Cortex Hormones/therapeutic use , Animals , Anti-Inflammatory Agents/administration & dosage , Anticonvulsants/administration & dosage , Brain Diseases/drug therapy , Brain Diseases/parasitology , Calcinosis/parasitology , Consensus , Epilepsy/drug therapy , Female , Humans , Male , Neurocysticercosis/diet therapy , Seizures/drug therapy , Taenia , Treatment Outcome
13.
PLoS Negl Trop Dis ; 14(7): e0008294, 2020 07.
Article in English | MEDLINE | ID: mdl-32673333

ABSTRACT

As members of the Pan American Health Organization (PAHO) and World Health Organization (WHO) guidelines development group on chemotherapy strategies for the control of Taenia solium taeniasis, we are very disappointed at the systematic review by Haby and colleagues. With respect to the analysis of efficacy, the authors did not account for differences in the methods used to ascertain the outcome in the studies analyzed. There are also major concerns regarding the safety analyses. Few of the included studies used carefully designed active surveillance protocols to detect epileptic seizures and/or chronic progressive headaches. These neurologic side effects, due the inadvertent killing of viable brain cysts, have been noted after mass therapy with praziquantel and albendazole. We wholeheartedly agree with the authors' statement in their discussion that control programs applying chemotherapy using mass drug administration "need to be informed by evidence of the best drug and dose in terms of efficacy and side-effects." Unfortunately, the flawed analysis that was published is contrary to that goal.


Subject(s)
Cysticercosis , Taenia solium , Taeniasis , Albendazole , Animals , Praziquantel
14.
Expert Opin Ther Targets ; 24(9): 915-922, 2020 09.
Article in English | MEDLINE | ID: mdl-32552166

ABSTRACT

Introduction Cryptosporidium species are protozoan parasites that are important causes of diarrheal disease including waterborne outbreaks, childhood diarrhea in resource-poor countries, and diarrhea in compromised hosts worldwide. Recent studies highlight the importance of cryptosporidiosis in childhood diarrhea, malnutrition, and death in resource-poor countries. Despite this, only a single drug, nitazoxanide, has demonstrated efficacy in human cryptosporidiosis and its efficacy is limited in malnourished children and patients with HIV. Areas covered In this review, we highlight work on potential targets for chemotherapy and review progress on drug development. A number of new targets have been identified for chemotherapy and progress has been made at developing drugs for these targets. Targets include parasite kinases, nucleic acid synthesis and processing, proteases, and lipid metabolism. Other groups have performed high-throughput screening to identify potential drugs. Several compounds have advanced to large animal studies. Expert opinion Development of drugs for cryptosporidiosis has been plagued by a lack of success. Barriers have included poor correlations between in vitro activity and clinical success as well as frequent unanticipated adverse effects. Without a clear pathway forward, it is wise to maintain a diverse development pipeline. Drug developers should also realize that success will likely require a sustained, methodical effort.


Subject(s)
Antiprotozoal Agents/pharmacology , Cryptosporidiosis/drug therapy , Molecular Targeted Therapy , Animals , Antiprotozoal Agents/adverse effects , Child , Child Nutrition Disorders/complications , Cryptosporidiosis/parasitology , Diarrhea/drug therapy , Diarrhea/parasitology , Drug Development , HIV Infections/complications , High-Throughput Screening Assays , Humans
15.
Mol Biochem Parasitol ; 237: 111277, 2020 05.
Article in English | MEDLINE | ID: mdl-32348840

ABSTRACT

Cryptosporidiosis is an obligate intracellular pathogen causing diarrhea. Merozoite egress is essential for infection to spread between host cells. However, the mechanisms of egress have yet to be defined. We hypothesized that Cyclic GMP-Dependent Protein Kinase G (PKG) may be involved in Cryptosporidium egress. In this study, Cryptosporidium parvum PKG was silenced by using antisense RNA sequences. PKG-silencing significantly inhibited egress of merozoites from infected HCT-8 cells into the supernatant and led to retention of intracellular forms within the host cells. This data identifies PKG as a key mediator of merozoite egress, a key step in the parasite lifecycle.


Subject(s)
Cryptosporidium parvum/genetics , Cyclic GMP-Dependent Protein Kinases/genetics , Host-Parasite Interactions/genetics , Merozoites/genetics , Protozoan Proteins/genetics , Cell Line , Cryptosporidium parvum/enzymology , Cryptosporidium parvum/growth & development , Cyclic GMP-Dependent Protein Kinases/antagonists & inhibitors , Cyclic GMP-Dependent Protein Kinases/metabolism , Epithelial Cells/parasitology , Gene Expression , Gene Silencing , Humans , Merozoites/enzymology , Protozoan Proteins/antagonists & inhibitors , Protozoan Proteins/metabolism , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism
16.
N Engl J Med ; 382(14): 1379-1380, 2020 04 02.
Article in English | MEDLINE | ID: mdl-32242378
17.
Parasitol Int ; 76: 102092, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32120049

ABSTRACT

BACKGROUND: Regulatory T-cells (Tregs) are increased in patients with HTLV-1/Strongyloides stercoralis co-infection, and they may modify otherwise protective antigen-specific cytokine production. We hypothesized that effective anti-helminthic treatment would decrease Tregs and restore antigen-specific cytokine responses. METHODS/RESULTS: We enrolled 19 patients with Strongyloides larvae in their stool by Baerman's test. Six were positive and 13 negative for antibody to HTLV-1 by ELISA, with positive tests confirmed by immunoblot. Before treatment, co-infected subjects had higher Tregs percentages and lower antigen-stimulated IL-5 levels compared to subjects with Strongyloides without HTLV-1. All patients were treated with ivermectin. After effective treatment, Tregs percentages decreased in patients with HTLV-1; however, antigen-specific IL-5 production remained blunted in co-infected subjects. CONCLUSION: These results suggest that treating strongyloidiasis infection decreases circulating Tregs, but antigen-specific cytokine remains altered. This may reflect blunting of sensitization by Tregs.


Subject(s)
HTLV-I Infections/virology , Strongyloides stercoralis/drug effects , Strongyloidiasis/drug therapy , T-Lymphocytes, Regulatory/drug effects , Adult , Animals , Coinfection/parasitology , Coinfection/virology , Cytokines/drug effects , Cytokines/physiology , Female , Humans , Male , Middle Aged , Strongyloidiasis/physiopathology , T-Lymphocytes, Regulatory/physiology , Treatment Outcome
20.
PLoS Negl Trop Dis ; 13(6): e0007415, 2019 06.
Article in English | MEDLINE | ID: mdl-31170141

ABSTRACT

BACKGROUND: Strongyloides stercoralis is an intestinal nematode unique in its ability to replicate in the human host, allowing ongoing cycles of autoinfection, persisting for decades within the same host. Although usually asymptomatic, overwhelming infections can occur in Strongyloides and HTLV-1 co-infected individuals (SS/HTLV-1). Regulatory T cells (Tregs) are able to blunt specific Th2 responses necessary to control the parasite. We previously reported that peripheral blood Tregs are increased in SS/HTLV-1 and correlate with low Th2 responses. We hypothesized that Tregs are also increased at the site of infection in duodenal mucosa. METHODS: Paraffin embedded duodenal biopsies were obtained from 10 SS/HTLV-1 patients, 3 controls with non-parasitic chronic duodenitis, and 2 healthy controls. Immunohistochemistry was performed using monoclonal antibodies against human CD3, CD8, IgE and FoxP3. The number of cells were counted using a conventional light microscope. The number of CD3+, CD8+, FoxP3+ and IgE positive cells per 0.35 mm2 was measured using ImagePro Plus software comparing areas adjacent or distant from parasite material. RESULTS: In patients with SS/HTLV-1, T lymphocyte counts and CD8+ cells were lower in areas adjacent to the parasite compared to non-adjacent areas (CD3+: adjacent: 6.5 [Interquartile range (IQR: 2.8-12.3)]; non-adjacent: 24.5 [IQR: 20.9-34.4]; Mann-Whitney p = 0.0003; CD8+: adjacent: 4.5 [IQR: 2.3-11.8]; non-adjacent: 21 [IQR: 15.3-42.9]; Mann-Whitney p = 0.0011). Tregs cells in the intestines (FoxP3+ expressing cells) were increased in patients with SS/HTLV-1 compared with patients with chronic duodenitis (SS/HTLV-1: 1.5 [IQR: 0.7-2.3]; duodenitis controls: 0 [range 0-0.7]; healthy controls: 0; Mann-Whitney p = 0.034). There was also a trend towards fewer eosinophils adjacent to the parasites. Among SS/HTLV-1 patients the number of IgE expressing cells was increased for in areas not adjacent to the parasite compared to non-adjacent areas (ANOVA, p = 0.001). CONCLUSIONS: Our data shows increased Treg cell numbers localized adjacent to the parasites in the duodenum SS/HTLV-1 patients. In addition, other T lymphocytes and IgE expressing cells were decreased adjacent to the parasites, suggesting an important role for Tregs in down-regulating local parasite effector responses.


Subject(s)
Coinfection/pathology , Duodenum/pathology , HTLV-I Infections/pathology , Immunoglobulin E/analysis , Immunologic Factors/analysis , Strongyloidiasis/pathology , T-Lymphocytes, Regulatory/immunology , Adolescent , Adult , Biopsy , Coinfection/complications , Female , Gene Expression , HTLV-I Infections/complications , Humans , Immunohistochemistry , Intestinal Mucosa/pathology , Male , Middle Aged , Strongyloidiasis/complications , Young Adult
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