Alterations in lipoprotein density classes in infantile visceral leishmaniasis: presence of apolipoprotein SAA

Epidemiological profile of visceral leishmaniasis in northern Morocco (2009-2018)

Introduction

visceral leishmaniasis (VL) represents the most serious and severe form of leishmaniasis in Northern Morocco. In this context, the objective of this study was to describe the epidemiological profile of VL in the Tangier Tetouan Al-Hoceima region from 2009 to 2018.

Methods

the epidemiologic data was collected from April 28th, 2019 to February 2nd, 2020 from files and investigation reports of cases. Additionally, annual reports for VL from the health services and provincial laboratories of parasitology were consulted. The analysis was conducted using statistical package for the social sciences (SPSS) v26 software.

Results

the study included 304 cases. Chefchaouen province was the highest endemic area (54.5%). The cases in the spring reached 36.5% and were characterized by age ≤5 years old (78.8%), male gender (M/F=1.3) and rural residents (91.4%). The number of inhabitants per household of cases was >5 persons (68.5%). A total of 94.3% and 98% had no suspect cases around or in their homes, respectively. Farmers accounted for 74.5% of cases. Signs of fever were present in 17.4% of cases, with 67.3% of these cases presenting these signs for a duration of more than 30 days. A total of 64.2% cases were diagnosed within a month. The serological test was used for diagnosis in 67.1% of cases and for the treatment, glunantime® was used in all cases (100%).

Conclusion

to eliminate the VL infection, it's necessary to monitor the entomological, mammalogical investigation. Also, to activate the Integrated Vector Control Management Committee at the most endemic province and to inform the community as well as the professionals of health about the VL control measures. A correlational study of the VL socio-economic and climate factors is recommended.

The Inflammatory Effects of Dietary Lipids Regulate Growth of Parasites during Visceral Leishmaniasis

Visceral leishmaniasis is a potentially fatal disease caused by the protozoon Leishmania donovani or L. infantum (Li). Although previous studies revealed that high lipid intake reduces parasite burdens in Leishmania donovani-infected mice, the specific contributions of dietary lipids to Li-associated pathogenesis are not known. To address this, we evaluated parasite growth, liver pathology, and transcriptomic signatures in Li-infected BALB/c mice fed either a control, high-fat, high-cholesterol, or high-fat–high-cholesterol diet. Using quantitative PCR (qPCR), we observed significantly reduced liver parasite burdens in mice fed the high-fat–high-cholesterol diet compared to mice fed the control diet. In contrast to the liver, parasite expansion occurred earlier in the spleens of mice fed the experimental diets. Histological examination revealed an intense inflammatory cell infiltrate in livers predominantly composed of neutrophils caused by the high-fat–high-cholesterol diet specifically. After 8 weeks of infection (12 weeks of diet), Illumina microarrays revealed significantly increased expression of transcripts belonging to immune- and angiogenesis-related pathways in livers of both uninfected and Li-infected mice fed the high-fat–high-cholesterol diet. These data suggest that increased fat and cholesterol intake prior to Li infection leads to a hepatic inflammatory environment and thus reduces the parasite burden in the liver. Defining inflammatory signatures as well as pathology in the liver may reveal opportunities to modify the therapeutic approach to Li infection.

IMPORTANCE Leishmaniasis is a spectrum of diseases caused by Leishmania species protozoa that is most common in warm climates, coinciding with impoverished regions. Visceral leishmaniasis is a potentially fatal disease in which parasites infect reticuloendothelial organs and cause progressive wasting and immunocompromise. The distribution and demographics of visceral leishmaniasis have changed over recent years, coinciding with modernizing societies and the increased availability of Western diets rich in lipid content. We report here that increased dietary fat and cholesterol intake affected disease pathogenesis by increasing inflammation and reducing localized parasite burdens in the liver. These diet-induced changes in disease pathogenesis might explain in part the changing epidemiology of visceral leishmaniasis. A relationship between diet and inflammatory responses may occur in leishmaniasis and other microbial or immune-mediated diseases, possibly revealing opportunities to modify the therapeutic approach to microbial infections.

Expression of Serum Exosomal miRNA 122 and Lipoprotein Levels in Dogs Naturally Infected by Leishmania infantum: A Preliminary Study

Simple Summary

The immunopathogenesis of leishmaniasis is not completely understood. Exosomes are extracellular vesicles produced by most eukaryotic cells, containing various molecular constituents with biological effects (e.g., proteins, peptides, RNA). They play an important role in cell-to-cell signaling. Recently, exosomal microRNA were demonstrated to be able to regulate gene expression and protein production in mammalian cells, serving as potential biomarkers of disease. The microRNA miR-122 is a biomarker of hepatic damage widely studied in mice in the course of Leishmania infection. Leishmania organisms can interfere with miR-122 production leading to a dysfunction in cholesterol metabolism ensuring its proliferation in the infected host. In this study, we suggest that such a phenomenon may also occur in dogs affected by Leishmania infection.

Abstract

Current knowledge on the role of exosomal microRNA (miRNA) in canine leishmaniasis (CL), with particular regards to the interaction between miR-122 and lipid alterations, is limited. The aim of this study was to isolate/characterize exosomes in canine serum and evaluate the expression of miR-122 in ten healthy and ten leishmaniotic dogs. Serum exosomes were isolated using a polymer-based kit, ExoQuick^® and characterized by flow cytometry and transmission electron microscopy, whereas miR-122-5p expression was evaluated by quantitative reverse-transcriptase polymerase chain reaction. A significant decreased expression of exosomal miR-122-5p, decreased serum levels of high-density lipoproteins, and increased serum levels of low-density lipoproteins were seen in leishmaniotic dogs when compared with healthy dogs. These results suggest that hepatic dysfunctions induced by the parasite interfere with lipoprotein status. The decreased expression of exosomal miR122 represents an additional effect of Leishmania infection in dogs as in people.

Lipoprotein lipase and PPAR alpha gene polymorphisms, increased very-low-density lipoprotein levels, and decreased high-density lipoprotein levels as risk markers for the development of visceral leishmaniasis by Leishmania infantum

In visceral leishmaniasis (VL) endemic areas, a minority of infected individuals progress to disease since most of them develop protective immunity. Therefore, we investigated the risk markers of VL within nonimmune sector. Analyzing infected symptomatic and, asymptomatic, and noninfected individuals, VL patients presented with reduced high-density lipoprotein cholesterol (HDL-C), elevated triacylglycerol (TAG), and elevated very-low-density lipoprotein cholesterol (VLDL-C) levels. A polymorphism analysis of the lipoprotein lipase (LPL) gene using HindIII restriction digestion (N = 156 samples) (H+ = the presence and H− = the absence of mutation) revealed an increased adjusted odds ratio (OR) of VL versus noninfected individuals when the H+/H+ was compared with the H−/H− genotype (OR = 21.3; 95% CI = 2.32–3335.3; P = 0.003). The H+/H+ genotype and the H+ allele were associated with elevated VLDL-C and TAG levels (P < 0.05) and reduced HDL-C levels (P < 0.05). An analysis of the L162V polymorphism in the peroxisome proliferator-activated receptor alpha (PPARα) gene (n = 248) revealed an increased adjusted OR when the Leu/Val was compared with the Leu/Leu genotype (OR = 8.77; 95% CI = 1.41–78.70; P = 0.014). High TAG (P = 0.021) and VLDL-C (P = 0.023) levels were associated with susceptibility to VL, whereas low HDL (P = 0.006) levels with resistance to infection. The mutated LPL and the PPARα Leu/Val genotypes may be considered risk markers for the development of VL.

Visceral leishmaniasis is associated with marked changes in serum lipid profile

BACKGROUND

Infection is often accompanied by lipid profile alterations. The aim of this study was to evaluate the lipid profile changes in patients with visceral leishmaniasis (VL).

MATERIALS AND METHODS

We included 15 patients [10 men, aged 50 (24-82) years old] with VL and 15 age- and sex-matched controls. The parameters estimated at diagnosis and 4 months after VL resolution were total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), triglycerides (TGs), low-density lipoprotein cholesterol (LDL-C), apolipoproteins (apo) A-Ι, B, E, C-II, C-III, lipoprotein (a) [Lp(a)], activities of lipoprotein-associated phospholipase A2 (Lp-PLA2), HDL-Lp-PLA2, PON1 (paraoxonase 1) and cholesterol ester transfer protein (CETP), cytokines (interleukins 1β and 6 and tumour necrosis factor α), as well as LDL subfraction profile.

RESULTS

Patients with VL at diagnosis had lower levels of TC, LDL-C, apoΒ and Lp(a), and higher TG and apoE concentrations compared with 4 months after VL resolution. The activities of Lp-PLA2, HDL-Lp-PLA2 and ΡΟΝ1 were reduced at diagnosis compared with post-treatment values. VL patients had decreased levels of both large and sdLDL-C at diagnosis; no effect on mean LDL particle size was observed. Patients with VL at diagnosis had decreased HDL-C and apoA-I concentrations; these increased 4 months after VL resolution, but remained lower compared with controls. The activities of HDL-Lp-PLA2 and PON1 remained lower in patients after VL resolution compared with controls.

CONCLUSIONS

Patients with VL exhibit increased TG levels and decreased cholesterol subclasses at diagnosis. HDL-C, apoA-I and associated enzymes remain lower 4 months after VL resolution compared with controls.

Liver biopsy in the diagnosis of visceral leishmaniasis

AIM

To determine whether liver biopsy might be useful in the diagnosis of visceral leishmaniasis when bone marrow examination and serologic tests are inconclusive.

METHODS

Over a 10-year period, liver biopsy was performed in five children with suspected visceral leishmaniasis when indirect hemagglutination tests and bone marrow aspirations were not diagnostic.

RESULTS

Leishmania amastigotes were seen in Kupffer cells in all patients. The accompanying liver histopathological findings were ischemic necrosis in two children, macrovesicular steatosis in two children, portal inflammatory inflammation in two children, and piecemeal necrosis in one child. During the study period, 32 additional pediatric visceral leishmaniasis cases were diagnosed by bone marrow examination.

CONCLUSION

Liver biopsy can be recommended for diagnosing suspected visceral leishmaniasis in children when serology and bone marrow aspiration are inconclusive.

Using serum amyloid A to screen dairy cows for sub-clinical inflammation

In this study, 232 lactating dairy cows from six herds were observed for clinical signs of inflammation and simultaneously had blood samples drawn to determine whether or not Serum Amyloid A (SAA) was present. Serum protein electrophoresis and white blood cell differential count revealed inflammation in SAA+ samples but not in SAA-samples. Using positive SAA test results as the standard for presence of inflammation, clinical findings consistent with inflammation concurred with positive SAA results only 26% of the time (p<.001) while the lack of clinical signs consistent with inflammation concurred with negative SAA results 95% of the time (p<.001). There was also a significant difference (p<.005) in management styles in that cows permanently fed on wilted/cured forages and kept inside had a 26% prevalence of positive SAA blood samples whereas the overall prevalence of SAA+ samples was 16%. These findings indicate that whole herd screening using SAA can be of value to the veterinarian in helping to identify cows with inflammatory diseases. From a public health perspective, SAA testing of cows going to market can help differentiate those not needing intensive inspection from those that do.