Parasites and chronic renal failure

The Association of Toxoplasma gondii IgG Antibody and Chronic Kidney Disease Biomarkers

BACKGROUND

Toxoplasma gondii (T. gondii) is a parasite that infects more than 40 million Americans and causes toxoplasmosis. Most cases of toxoplasmosis are asymptomatic; however, T. gondii is capable of invading organs like the kidney, causing chronic infections and cell destruction.

METHODS

This study focused on evaluating the association between T. gondii exposure and chronic kidney disease (CKD) using data from the 2009-2010 National Health and Nutrition Examination Survey (NHANES). T. gondii exposure was assessed using Toxoplasma gondii IgG antibody status, and the status of CKD was assessed using the CKD biomarkers. The evaluation of risk rate and population prevalence was performed. In addition, multivariable regression models were used to further investigate this association after adjusting for sociodemographic, anthropometric, behavioral, and clinical covariates commonly associated with kidney dysfunction.

RESULTS

The positive T. gondii IgG antibody participants had significantly higher levels of CKD biomarkers, including second albumin-to-creatinine ratio (p = 0.0376), second albuminuria (p = 0.0005), and persistent albuminuria (p < 0.0001) compared to the negative participants. Furthermore, there were statistical associations between T. gondii exposure and the status of CKD (negative vs. positive) (p = 0.0001), and between T. gondii exposure and the CKD stage (negative, stage 1, …, stage 5) (p = 0.0004). Without adjusting for age, the positive T. gondii participants had a significantly higher risk (27% higher) of having CKD than the negative participants (RRcrude = 1.27, 95% CI: 1.09-1.49). The age-adjusted prevalence of CKD was higher among Toxoplasma-positive participants compared to the Toxoplasma-negative participants (10.45 vs. 8.99). T. gondii infection was significantly associated with CKD (OR = 1.40, 95% CI = 1.06-1.84, p = 0.00447) after adjusting for age, gender, race/ethnicity, and BMI. Age was positively associated with CKD (OR = 8.89, 95% CI = 6.31-12.51, p < 0.0001) with the participants 45+ years old being 8.89 times more likely to have CKD than those who are <45 years old, after adjusting for T. gondii infection, gender, race/ethnicity, and BMI. Moreover, positive T. gondii increased the odds of CKD progression (OR = 1.41, 95% CI = 1.07-1.86, p = 0.0424).

CONCLUSIONS

Positive T. gondii IgG antibody is associated with CKD and the progression of CKD stages. This association is more apparent among older people. Further investigations are needed to examine these findings in different geographical locations and among differentially exposed populations.

Pathomechanisms in the Kidneys in Selected Protozoan Parasitic Infections

Leishmaniasis, malaria, toxoplasmosis, and acanthamoebiasis are protozoan parasitic infections. They remain important contributors to the development of kidney disease, which is associated with increased patients' morbidity and mortality. Kidney injury mechanisms are not fully understood in protozoan parasitic diseases, bringing major difficulties to specific therapeutic interventions. The aim of this review is to present the biochemical and molecular mechanisms in kidneys infected with Leishmania spp., Plasmodium spp., Toxoplasma gondii, and Acanthamoeba spp. We present available mechanisms of an immune response, oxidative stress, apoptosis process, hypoxia, biomarkers of renal injury in the serum or urine, and the histopathological changes of kidneys infected with the selected parasites. Pathomechanisms of Leishmania spp. and Plasmodium spp. infections have been deeply investigated, while Toxoplasma gondii and Acanthamoeba spp. infections in the kidneys are not well known yet. Deeper knowledge of kidney involvement in leishmaniasis and malaria by presenting their mechanisms provides insight into how to create novel and effective treatments. Additionally, the presented work shows gaps in the pathophysiology of renal toxoplasmosis and acanthamoebiasis, which need further research.

Toxoplasma gondii in cancer patients receiving chemotherapy: seroprevalence and interferon gamma level

Toxoplasma gondii is an opportunistic parasite causing life-threatening diseases in immune-compromised patients. The purpose of the study is to determine the seroprevalence of Toxoplasma gondii in chemotherapy receiving cancer patients in relation to different types of malignancies, and to estimate the level of interferon gamma in Toxoplasma seropositive and seronegative cancer patients and healthy controls. Anti-Toxoplasma IgG and IgM antibodies, and interferon gamma were analyzed in 120 cancer patients receiving chemotherapy (60 having hematological malignancies and 60 with solid organ tumors) and 60 healthy controls using ELISA method. Toxoplasma (IgG and IgM) were determined in (66.7% and 9.2%) of the cancer group compared to (33.3% and 6.7%) of the control group with statistical significance only in IgG seropositivity (p < 0.001, OR = 4). Patients with hematological malignancies had higher IgG seropositivity than solid organ tumors (40% vs 26.7%). The difference between the groups was statistically significant (p = 0.002, OR = 3.5). Median level of interferon gamma was in the same range between cancer patients and control group. However, it was highly elevated in Toxoplasma seropositive (76 pg/ml) than seronegative (44.5 pg/ml) cases with statistical significance (p < 0.001). T. gondii infection remains a major threat to cancer patients and still needs proper screening, diagnosis and treatment.

Opportunistic parasitoses among Egyptian hemodialysis patients in relation to CD4+ T-cell counts: a comparative study

Background

Some reports are available on the prevalence of opportunistic parasitoses among hemodialysis (HD) patients, yet there is a paucity of data on the association of CD4+ T-cell counts with such infections. Therefore, this study aimed to determine the prevalence of intestinal parasites and Toxoplasma gondii in relation to CD4+ counts among HD patients in Alexandria, Egypt.

Methods

A comparative cross-sectional study was conducted on 120 HD patients and 100 apparently healthy individuals between December 2014 and January 2016. Data and samples (stool and blood) were collected from the participants after obtaining their informed consent. Stool samples were examined for parasites after concentration and staining, EDTA-blood samples were used for CD4+ counting by flow cytometry, and sera were analyzed for anti-Toxoplasma IgM and IgG antibodies.

Results

A significantly higher prevalence rate of intestinal parasitoses was found among HD patients compared to apparently healthy individuals (52.5% vs. 12.0%, respectively), with absence of helminths. Cryptosporidium species (32.5%), B. hominis(24.2%) and microsporidia (11.7%) were the most frequent parasites among HD patients, while B. hominis (13.0%), Cryptosporidium species (11.0%) and G. lamblia (4.0%) were the most frequent parasites among their counterparts. Statistically significant differences in parasite infection rates between patients and their counterparts were found for Cryptosporidium species, B. hominis and microsporidia. However, parasite species were not significantly associated with diarrhea. On the other hand, the overall T. gondii seroprevalence rate among HD patients was significantly higher than that among their counterparts (33.3% vs. 8%, respectively). HD patients with CD4+ counts < 200 cells/μl were twice more exposed to intestinal parasitoses compared to those with counts ≥200 cells/μl, but the difference was not statistically significant. However, low CD4+ counts were significantly associated with higher rates of Cryptosporidium species, microsporidia and T. gondii.

Conclusions

Intestinal parasitoses and T. gondii infection rates are significantly higher among Egyptian HD patients compared to apparently healthy individuals, with Cryptosporidium species, B. hominis, microsporidia and T. gondii being the most frequent parasites. CD4+ counts < 200 cells/μl are significantly associated with Cryptosporidium species, microsporidia and T. gondii among HD patients. Therefore, regular screening of HD patients for opportunistic parasites is recommended.

Cryptosporidium infection in chronic kidney disease patients undergoing hemodialysis in Egypt

Patients with chronic renal failure are more susceptible to infections due to acquired immunodeficiency caused by uremia. Parasitic infections are one of the significant causes of morbidity and mortality in those patients, So we aimed to assess the prevalence of Cryptosporidium spp. and other protozoan infections in patients undergoing hemodialysis in Qena Governorate, Upper Egypt. The present study took place in Qena University Hospitals, Egypt. Participants were 150 Chronic Kidney Disease (CKD) patients undergoing hemodialysis, and 50 healthy individuals. After questionnaire, three consecutive stool samples from each participant were examined macroscopically and microscopically by different techniques for the presence of different stages of different protozoa. 66% of CKD patients and 26% of the control group were infected with intestinal protozoa. Cryptosporidium spp. were the protozoa with the highest prevalence in cases (40%) and control (6%) with statistical significance (P < 0.05). It was detected only in watery stool samples (P value < 0.05). Residence, age and gender were not significant variables in the prevalence of infection among patients with CKD. In Egypt, few studies had reported the prevalence of Cryptosporidiosis in chronic renal patients. Cryptosporidium infection should be suspected in all cases of prolonged watery diarrhea in CKD patients and stool samples should be examined using special stains as cold modified Ziehl-Neelsen staining for proper diagnosis of Cryptosporidium infections.

Toxoplasmosis an Overlooked Disease: Seroprevalence in Cancer Patients

Background

Toxoplasmosis is one of the most important cosmopolitan life-threatening diseases in immune-compromised patients. It is caused by an intracellular protozoon: Toxoplasma gondii (T. gondii). The parasite can cause pneumonia, encephalitis or disseminated disease in immune-deficient patients and dangerous congenital anomalies in infants born to mothers infected during early pregnancies. The present study aims to evaluate the prevalence of toxoplasmosis in Egyptian cancer patients and to correlate the prevalence with type of malignancy and the different cancer treatment modalities.

Materials and Methods

Blood samples from 150 cancer patients and 50 control subjects have been examined for presence of anti-toxoplasma antibodies using a lateral flow chromatographic immunoassay.

Results

Among cancer patients included in this study, the prevalence of anti- T.gondii antibodies was 20% for IgG and 4% for IgM, while in the control group it was 8% and 2% in the same order. This difference was statistically significant for IgG (P =0.003) but not for IgM (P = 0.44). Patients with solid organ tumors treated with chemotherapy had the highest prevalence rate of toxoplasmosis (28%). It was also found higher in males (26%) than females (10%) and higher among urban (18%) than rural dwellers (16%).

Conclusion

Cancer patients showed a significantly higher rate of infection with T. gondii than their cross-matched control. For that reason, we recommend the inclusion of a screening test for toxoplasmosis in their routine workup.

Molecular characterization of Acanthamoeba strains isolated from the oral cavity of hemodialysis patients in Iran

Free-living amoebae (FLA) of the genus Acanthamoeba are opportunistic pathogenic agents able to cause life-threatening infections in immunosuppressed patients. Chronic kidney disease impairs adaptive and innate immunity. Thus, patients with chronic kidney disease are prone to opportunistic infections by potentially pathogenic FLA. Therefore, in the present study, the investigation of Acanthamoeba genotypes isolated from the oral cavity of hemodialysis patients of reference hospitals in Iran was aimed, using both morphology and molecular (sequence-based analysis) tools. Furthermore, classification of the strains at the genotype level was performed on the basis of differences in the diagnostic fraction 3 (DF3) region of the 18S rRNA gene. The pathogenic potential of the isolated amoebae was also determined using thermotolerance and osmotolerance assays. Out of the 187 oral cavity samples investigated, nine (4.8%) were positive for FLA. DNA sequencing of the ASA.A1 region of the 18S rRNA gene revealed that the isolated strains belonged to the Acanthamoeba T1 and T4 genotypes. Genotype T1 was isolated for the first time from a patient in Iran. Interestingly, the T1 strain (AN2 strain) exhibits a high pathogenic potential in tolerance assays. The pathogenicity assay revealed that five strains were able to grow at high temperatures (37-40 °C) and high osmolarity (0.5 and 1 M D-mannitol) conditions; thus, they were considered as potentially pathogenic strains. Moreover, two of the patients were positive for Vermamoeba genus. The present study is the first report of genotype T1 isolation in Iran and the first to identify the occurrence of Acanthamoeba and Vermamoeba genera in patients undergoing hemodialysis worldwide. Monitoring hemodialysis and renal failure patients should be a priority for possible control of Acanthamoeba and other FLA-related diseases.

Prevalence and clinical features of Cryptosporidium infection in hemodialysis patients

AIM

This cross-sectional study aims to assess the prevalence of Cryptosporidium in hemodialysis patients compared with healthy individuals in central Iran from August 2014 to January 2015.

BACKGROUND

Cryptosporidiosis is a major cause of acute and persistent diarrhea with significant morbidity and mortality in immunocompromised patients such as those undergoing renal dialysis.

METHODS

Three stool samples were collected from 330 hemodialysis patients and 150 healthy individuals on 3 consecutive days. The samples were screened for Cryptosporidium infection using formalin-ether sedimentation and modified Ziehl-Neelsen staining. Demographic variables as well as risk factors were recorded.

RESULTS

Out of 330 dialysis patients and 150 healthy individuals, 10 (3%) and 1 (0.7%) were infected with Cryptosporidium, respectively. We found statistically significant differences between infection and place of residency, hygiene status, education level, diarrhea, and abdominal pain in the two groups (p<0.05). On the other hand, there was no relationship between infection and sex, contact with domestic animals, fever, vomiting, nausea, flatulence, anorexia, duration of dialysis and underlying disorders in the two groups. Also, there was a statistically significant difference between age and infection in hemodialysis patients (p=0.003). A higher infection rate was observed in patients under 20 years of age.

CONCLUSION

Risk factors for Cryptosporidium infection must be controlled. We strongly recommended that stool samples from such patients, especially those with severe or prolonged diarrhea, should be examined with modified Ziehl-Neelsen staining for appropriate and timely treatment.

Prevalence of Intestinal Protozoa among Saudi Patients with Chronic Renal Failure: A Case-Control Study

It has been hypothesized that chronic renal failure (CRF) predisposes patients to infection with intestinal protozoa. We tested this hypothesis with a matched case-control study to determine the prevalence of these protozoa and their diarrhea associated symptoms among 50 patients with CRF (cases) from Taif, western Saudi Arabia. Fifty diarrheal patients without CRF were recruited in the study as controls. Participants were interviewed by a structured questionnaire and stool samples were collected. Samples were thoroughly examined with microscopy and three coproantigens detection kits. Enteric protozoa were detected in 21 cases and 14 controls. Blastocystis spp. were the most predominant parasite (16% in cases versus 8% in controls), followed by Giardia duodenalis (10% in cases versus 12% in controls) and Cryptosporidium spp. (10% in cases versus 6% in controls). Cyclospora cayetanensis was identified in two cases, while Entamoeba histolytica was described in one case and one control. Intestinal parasitism was positively associated with the male gender, urban residence, and travel history. Clinical symptoms of nausea/vomiting and abdominal pain were significantly varied between the parasitized cases and controls (P value ≤ 0.05). Given the results, we recommend screening all diarrheal feces for intestinal protozoa in the study's population, particularly those with CRF.