Cystoisospora Belli Infection Research Articles

Cystoisospora belli infection in a person with diabetes mellitus and chronic kidney disease[AM1

Cystoisospora belli infection in a person with diabetes mellitus and chronic kidney disease[AM1

1256 Cystoisospora belli Infection of the Gallbladder: More Common Than You May Think

INTRODUCTION: Cystoisosporiasis is an underrecognized gallbladder infection of immunocompetent hosts due in part to subtle histopathologic findings and low index of suspicion during examination of routine cholecystectomy specimens. This case will highlight the importance of detecting the organism in order to gain understanding of its life cycle and to raise awareness of the potential symptoms for those who become immunosuppressed. CASE DESCRIPTION/METHODS: A 65-year-old male with compensated cirrhosis presented with complaints of intermittent right upper quadrant pain for three months. He denied symptoms of diarrhea, jaundice, fever, chills, recent travel and sick contacts. CBC, BMP and liver enzymes were unremarkable. A right upper quadrant ultrasound illustrated multiple gallstones within the gallbladder along with wall thickening measuring up to 4.8 mm. The patient underwent a laparoscopic cholecystectomy with resolution of symptoms. Pathologic evaluation of the resected gallbladder described elongated “banana-shaped” zoites of C. belliwithin parasitopherous vacuoles in the gallbladder columnar mucosa. DISCUSSION: Cystoisospora belli (C. belli) is an intracellular protozoan of the intestinal epithelium often associated with gastrointestinal (GI) disease in immunocompromised patients or those who travel to endemic areas. The infection is acquired by fecal-oral route through ingestion of infective oocysts in contaminated water. Symptoms of C. belli include watery diarrhea, abdominal pain, nausea, vomiting and weight loss due to malabsorption, whereas most infected immunocompetent patients remain asymptomatic. C. belli is known to reside within parasitophorous vacuoles in epithelial cells of the small intestine; however, incidence of gallbladder infection is on the rise as there becomes an increased awareness and recognition on the part of the pathologist. Previously, lack of recognition has stemmed from multiple factors including a low index of suspicion in patients without clinical symptoms or those who remain immunocompetent, the underwhelming appearance of infected gallbladders with lack of significant tissue reaction, as well as the sparse distribution of the organisms themselves. The unexpectedly high prevalence in gallbladder specimens has given rise to the idea that the gallbladder may be an anatomic reservoir for this commensal organism in the immunocompetent host. For this reason, C. belli infection should be considered in patients exhibiting typical GI symptoms following immunosuppression.

Unexpectedly High Prevalence of Cystoisospora belli Infection in Acalculous Gallbladders of Immunocompetent Patients.

ObjectivesIndications for cholecystectomy have changed dramatically over the past three decades. Cystoisospora belli has been reported in cholecystectomy specimens of immunocompetent patients. The present study was designed to determine the prevalence and clinical association of C belli in the gallbladder.MethodsThe study included retrospective review of cholecystectomy specimens (n = 401) removed for various indications, and a prospective cohort of cholecystectomy specimens (n = 22) entirely submitted for histologic evaluation. Correlations of presence of C belli with age, sex, clinical indication, and abnormalities of preoperative laboratory values were assessed by Fisher exact test.ResultsC belli was identified in 39/401 (9.7%) of the retrospective cohort, and 6/22 (27.3%) of the entirely submitted specimens. The presence of C belli showed no correlation with age, sex, clinical indication, or laboratory abnormalities.ConclusionsC belli resides in a latent state in the gallbladder and may be best considered a commensal organism.

Epithelial Inclusions in Gallbladder Specimens Mimic Parasite Infection: Histologic and Molecular Examination of Reported Cystoisospora belli Infection in Gallbladders of Immunocompetent Patients.

Recent publications have described epithelial cytoplasmic vacuoles and inclusions incidentally noted within gallbladder epithelium and concluded that they represent coccidian parasite infection, in particular, Cystoisospora belli. We identified 8 gallbladder specimens from our institution in the past 3 years in which this diagnosis was suggested or in which similar epithelial alterations were prominent. Molecular analysis was performed on the 8 gallbladder specimens and on 3 positive control specimens: small bowel biopsies from acquired immunodeficiency syndrome patients with diarrhea. Polymerase chain reaction using primers designed to amplify an internal transcribed spacer (ITS2) in the C. belli ribosomal gene cluster was performed on the DNA samples. All 8 gallbladder specimens were negative for amplification, while a product consistent with C. belli was amplified from all 3 positive controls. Histologically, the gallbladder cytoplasmic inclusions stained diffusely positive for Grocott-Gomori's methenamine silver and Periodic acid-Schiff with diastase. In contrast, sections from a positive control small bowel biopsy demonstrated organisms that were negative for Grocott-Gomori's methenamine silver and showed a distinct capsular and punctate internal staining on Periodic acid-Schiff with diastase in various parasite forms. Together, the lack of molecular evidence of C. belli and the distinct morphologic and special staining patterns in these gallbladders compared with positive control small bowel suggest that these epithelial changes do not represent true C. belli infection. Our results suggest that gallbladders of immunocompetent patients may occasionally show epithelial changes that can morphologically mimic C. belli infection. Pathologists should be aware of this histologic variant to minimize unnecessary treatment, testing, and patient anxiety.

Cystoisospora belli infection in HIV patients: Analysis of cases with different clinical evolution

Cystoisospora belli infection is one of the most important causes of watery diarrhea in patients with HIV and causes high rates of morbidity and mortality. A retrospective study was conducted in patients with HIV and diarrhea by C. belli. Clinical and laboratory characteristics were collected by analyzing clinical records. Four had recurrent diarrhea despite receiving secondary prophylaxis with cotrimoxazole and specific treatment, two of which had a good viral and immunological response to highly active antiretroviral therapy (HAART) at the time of diagnosis and antiparasitic treatment. While the remaining three did not receive prophylaxis, neither did HAART (two of them), but they responded well to treatment. C. belli is an important cause of diarrhea in HIV patients on HAART and prophylaxis, being able to have different clinical evolution. We suggest that persistent infection may be due to drug failure by intrinsic or extrinsic to the parasite causes, or to defects in restoration of the intestinal immune system, or both.

Cystoisospora belli Infection of the Gallbladder in Immunocompetent Patients: A Clinicopathologic Review of 18 Cases.

Cystoisospora belli, previously known as Isospora belli, is an obligate intracellular coccidian parasite that is most often associated with gastrointestinal disease in immunocompromised patients. In this study, we detail the clinicopathologic features of 18 cases of Cystoisospora infection affecting the gallbladder in immunocompetent individuals and compare them with a control group. Each case was reviewed for cholecystitis (none, acute, chronic), epithelial disarray, presence of intraepithelial lymphocytes (none, rare [≤5 per 20 epithelial cells], present [>5 per 20 epithelial cells]), architectural distortion, intramucosal eosinophilia, and mural thickening/serositis. The mean age of patients with Cystoisospora infection was 33 years and the male to female ratio 1:4.3. Cholecystectomy was performed for biliary dyskinesia (n=7), abdominal pain (n=7), suspected cholelithiasis (n=5), and cholecystitis (n=3). In 2 cases, Cystoisospora was found in donor gallbladders resected at the time of liver transplantation. Each case was characterized by eosinophilic, oval or banana-shaped intraepithelial parasites within perinuclear parasitophorous vacuoles. Most cases showed epithelial disarray and minimal intraepithelial lymphocytosis. Of the 11 cases with an average follow-up of 15 months, none had evidence of disease related to Cystoisospora infection within the biliary tract or elsewhere in the gastrointestinal tract. We present the largest series of gallbladder cystoisosporiasis in immunocompetent patients to date. Cystoisospora infection is underrecognized in the gallbladders of immunocompetent patients, in part due to the subtle findings in routine cholecystectomy specimens. On the basis of the clinical follow-up, gallbladder cystoisosporiasis in immunocompetent individuals appears to be a self-limited infection.