Sclerosing cholangitis associated to cryptosporidiosis in liver-transplanted children

Cryptosporidium sp. infection in solid organ transplant recipients: A systematic review and meta-analysis

(1) Background: Organ transplant recipients (OTRs) are vulnerable groups at risk of parasitic infections. This systematic review and meta-analysis aimed to evaluate the overall prevalence of Cryptosporidium sp. in OTRs and shed light on this potentially serious complication of organ transplantation. (2) Methods: We systematically searched studies on Cryptosporidium sp. infections in OTRs in four databases (Academia, PubMed, Scopus, and Science Direct). Random effects models were used to calculate pooled prevalence estimates with 95% confidence intervals (CIs). Sub-group and meta-regression analyses were conducted. A quality assessment of the included studies was also performed. (3) Results: Among 876 articles retrieved, 21 were included, accounting for 2,642 OTRs. Twenty studies were cross-sectional in design, of which seven reported data on a comparison group, and one was a retrospective cohort. The pooled prevalence of Cryptosporidium sp. in OTRs was 15% (95% CI: 7.4-24.6). Subgroup analysis revealed that the prevalence of Cryptosporidium sp. infection was higher in adults, symptomatics and developing countries and in studies using only non-molecular methods. However, substantial heterogeneity was reported. Low to moderate heterogeneity was observed in subgroups reporting lower prevalence Cryptosporidium sp. including children (5.8; 95% CI: 2.8-9.6), studies conducted in developed countries (5.8; 95% CI: 3.0-9.4) and studies using both molecular and non-molecular diagnostics (11.4; 95% CI: 6.4-17.4). The majority of the listed research reported low-medium quality scores. (4) Conclusion: Cryptosporidium sp. infection is a significant complication in OTRs with underreported prevalence. Preventive strategies to reduce the burden should include Cryptosporidium sp. routine screening for OTRs, particularly post-transplantation in patients with diarrhea. Additional well-designed research studies are required to determine the extent of the Cryptosporidium sp. burden in OTRs.

Developing an Integrated "Regression-QMRA method" to Predict Public Health Risks of Low Impact Developments (LIDs) for Improved Planning

Worldwide Low Impact Developments (LIDs) are used for sustainable stormwater management; however, both the stormwater and LIDs carry microbial pathogens. The widespread development of LIDs is likely to increase human exposure to pathogens and risk of infection, leading to unexpected disease outbreaks in urban communities. The risk of infection from exposure to LIDs has been assessed via Quantitative Microbial Risk Assessment (QMRA) during the operation of these infrastructures; no effort is made to evaluate these risks during the planning phase of LID treatment train in urban communities. We developed a new integrated "Regression-QMRA method" by examining the relationship between pathogens' concentration and environmental variables. Applying of this methodology to a planned LID train shows that the predicted disease burden of diarrhea from Campylobacter is highest (i.e. 16.902 DALYs/1000 persons/yr) during landscape irrigation and playing on the LID train, followed by Giardia, Cryptosporidium, and Norovirus. These results illustrate that the risk of microbial infection can be predicted during the planning phase of LID treatment train. These predictions are of great value to municipalities and decision-makers to make informed decisions and ensure risk-based planning of stormwater systems before their development.

Gastrointestinal parasites in immunocompromised patients; A comparative cross-sectional study

Gastrointestinal parasites (GIPs), including helminths and protozoa species, are a major health problem in many parts of the world. About 3.5 billion people are affected by the parasites worldwide. GIPs are one of the leading causes of death among immunocompromised individuals and can cause serious clinical complications, especially in people with Human Immunodeficiency Virus (HIV)/AIDS, hemodialysis patients, and transplant recipients. This study aimed to compare the prevalence of GIPs among immunocompromised patients and immunocompetent individuals in Lorestan province, West Iran. In the current study, with a sampling of 232 participants (114 hemodialysis, AIDS, and organ transplantation immunocompromised patients and 118 immunocompetent individuals as the control group), demographic characteristics and risk factors for GIPs were collected through a pre-designed questionnaire. Stool samples of patients and the control group were examined for GIPs using different diagnostic methods including direct smear (saline and Lugol's iodine), Ziehl-Neelsen staining, agar-plate culture, and concentration method (formalin ether sedimentation). To evaluate the relative status of the immune system, TCD4⁺ cells were counted in the blood samples of the subjects by flow cytometry. The results were analyzed using SPSS 21 software, Fisher exact, and chi-square statistical tests. Multivariate modeling of the data was performed using logistic regression. The prevalence of GIPs in immunocompromised patients was more than twice that of immunocompetent individuals in the control group (42.06% vs. 17.79%). The most prevalent parasites identified among immunocompromised patients were Cryptosporidium sp. (27.1%), Blastocystis sp. (16.7%), and Entamoeba coli (14.6%) respectively. Cryptosporidium sp. had the highest frequency among hemodialysis patients (6.49%), AIDS patients (26.92%), and transplant recipients (18.18%) respectively. Patients with AIDS had the highest positive results for Cryptosporidium sp. followed by Microsporidia sp. (23.7%). In immunocompetent individuals, the highest prevalence of GIPs was related to Blastocystis sp and Trichomonas hominis (28.57%). Statistical analysis of the data showed that there was a statistically significant difference between various age groups regarding infection with GIPs so the highest rate of GIPs infection was observed in the age group lower than 50 years (P = 0.035). The statistical difference between the variable of location and infection with GIPs was insignificant but remarkable (P = 0.070). According to the results, it can be concluded that GIP is more common in immunocompromised patients than in immunocompetent individuals with cryptosporidium sp. predominance. Due to the favorable conditions of immunocompromised patients for GIPs and considering them as one of the important sources of parasitic infections and parasite transmission in society, control, prevention, and monitoring of their social behaviors along with health issues are inevitable.

Complications of Cryptosporidium infection after pediatric liver transplantation: Diarrhea, rejection, and biliary disease

BACKGROUND

Cryptosporidium enteritis can be devastating in the immunocompromised host. In pediatric liver transplant recipients, infection may be complicated by prolonged carriage of the parasite, rejection, and biliary tree damage and fibrosis. Herein, we report on six patients and their long-term outcomes following cryptosporidiosis.

METHODS

We reviewed all cases of cryptosporidiosis in a pediatric liver transplant population over a 17-year period at a single center. Six patients with infection were identified, and their outcomes were analyzed.

RESULTS

Infection was associated with significant diarrhea and dehydration in all cases, and led to hospitalization in one-half of patients. Four of the six patients developed biopsy-proven rejection following infection, with three of those patients developing rejection that was recalcitrant to intravenous steroid treatment. Additionally, three patients developed biliary tree abnormalities with similarity to sclerosing cholangitis. In one patient, those biliary changes led to repeated need for biliary drain placement and advancing fibrotic liver allograft changes.

CONCLUSIONS

Cryptosporidiosis in pediatric liver transplant recipients may lead to significant complications, including recalcitrant episodes of rejection and detrimental biliary tree changes. We advocate for increased awareness of this cause of diarrheal disease and the allograft injuries that may accompany infection.

Prevalence of Intestinal Parasitic Infection in Cancer, Organ Transplant and Primary Immunodeficiency Patients in Tehran, Iran

Background:

Intestinal parasitic infection in immunodeficient patients especially those with impaired cellular immunity, like neoplasia, renal or heart transplant needs careful consideration. The objective of this study is to evaluate the prevalence of intestinal parasites in different group of patients including cancer patients; organ transplants recipients, and primary immunodeficiency patients.

Methods:

Stool samples from 190 patients including 80 patients with Primary Immunodeficiency, 85 cancer patients and 25 organ transplant recipients were collected; a direct examination with Phosphate buffered saline (PBS) and formalin ether concentration was performed. The DNA was extracted from parasitologically confirmed patients and nested PCR and sequencing was performed and new obtained sequences of Cryptosporidium parvum and Enterocytozoon bieneusi were compared with deposited ones.

Results:

In general, the prevalence of parasites was 26/80 (32.5%) in primary immunodeficiency, 22/85(25.9%) in cancer group, and 7/25 (28%) in organ transplant. The prevalence of intestinal parasitic infections in primary immunodeficiency patients were Blastocystis hominis 13 (16.2%), Giardia lamblia 10 (12.5%), Cryptosporidium 1(1.2%), Chilomastix mesnilii 1 (1.2%), Dientamoeba fragilis 1(1.2%). Of 25 organ transplants, 6 (24%) Cryptosporidium sp were found, all of which were confirmed as Cryptosporidium parvum and one case of Microspora in a heart transplant recipient was confirmed as Enterocytozoon bieneusi by PCR sequencing. The predominant intestinal parasitic infection in cancer patients was 19 (22.3%) Blastocystis hominis followed by two (2.3%) Giardia lamblia and one Dientamoeba fragilis 1 (1.1%).

Conclusion:

The high rate of infection with Blastocystis hominis was found in cancer patients especially colorectal cancer patients, so careful consideration should be given by physicians. Cryptosporidium sp was found to be the major cause of parasitic intestinal infection in patients with organ transplant compared to primary immunodeficiency patients; so transplant recipients undergoing immunosuppressive therapy should be considered as a risk group for acquiring microsporidiosis and Cryptosporidium infection.

Solid Organ Transplant and Parasitic Diseases: A Review of the Clinical Cases in the Last Two Decades

The aim of this study was to evaluate the occurrence of parasitic infections in solid organ transplant (SOT) recipients. We conducted a systematic review of literature records on post-transplant parasitic infections, published from 1996 to 2016 and available on PubMed database, focusing only on parasitic infections acquired after SOT. The methods and findings of the present review have been presented based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) checklist. From data published in the literature, the real burden of parasitic infections among SOT recipients cannot really be estimated. Nevertheless, publications on the matter are on the increase, probably due to more than one reason: (i) the increasing number of patients transplanted and then treated with immunosuppressive agents; (ii) the “population shift” resulting from immigration and travels to endemic areas, and (iii) the increased attention directed to diagnosis/notification/publication of cases. Considering parasitic infections as emerging and potentially serious in their evolution, additional strategies for the prevention, careful screening and follow-up, with a high level of awareness, identification, and pre-emptive therapy are needed in transplant recipients.

The evaluation of critically ill transplant patients with infectious diarrhea

PURPOSE OF REVIEW

The review summarizes the epidemiology, risk factors, clinical presentation, diagnosis and management of the most important etiologic agents of infectious diarrhea in critically ill transplant recipients.

RECENT FINDINGS

Diarrhea, frequently caused by infectious pathogens, can cause significant morbidity and mortality in transplant recipients. Diarrhea can lead to severe dehydration, acute renal failure, medication toxicity, rejection, graft-versus-host disease and impairs patients' quality of life. Opportunistic infectious pathogens can pose significant diagnostic and therapeutic challenges in immunocompromised hosts.

SUMMARY

In transplant recipients, it is vital to differentiate infectious from noninfectious diarrhea to adequately manage their therapeutic approach. Supportive measures and reduction in immunosuppression are essential for the treatment management.

Cryptosporidium spp. Infection in Solid Organ Transplantation: The Nationwide "TRANSCRYPTO" Study

BACKGROUND

Diarrhea is a frequent complication of solid organ transplantation. Cryptosporidiosis is classically reported in patients with acquired immunodeficiency syndrome and emerged as a cause of persistent diarrhea in solid organ transplant patients.

METHODS

Through the ANOFEL Cryptosporidium National Network and the French Transplantation Society, we collected all cryptosporidiosis cases identified in solid organ transplanted patients between 2006 and 2010 in France.

RESULTS

We reported 47 solid organ transplant recipients (41 kidneys) with cryptosporidiosis, mostly men (68%), with a median age of 52 (6-70) years old. Five patients had additional immunodepression favoring cryptosporidiosis (CD40 ligand deficiency [n = 1], human immunodeficiency virus infection [n = 4]). Cryptosporidiosis occurred at a median time of 3.4 (0-19.8) years posttransplant. Exposure to environmental risk factors was found before infection onset in 18 patients. Time between first symptoms and diagnosis was 10 (2-110) days. Four patients had associated extraintestinal location (biliary tract [n = 3] and lung [n = 1]). Thirty-five patients received specific therapy against cryptosporidiosis ie nitozoxanide, 25 in monotherapy, and 10 in association with azithromycin, 13 in association with immunosuppression (IS) reduction. Four patients were cured with IS treatment tapering only. The others patients had neither IS reduction nor specific therapy against cryptosporidiosis. Cryptosporidiosis was complicated by renal failure in 15 patients. Symptoms resolved after a median of 10 days of treatment. Six patients relapsed and 3 died, 1 with evolutive infection.

CONCLUSIONS

Cryptosporidiosis is a late posttransplant infection that disseminated to biliar duct or lung in 9% of patients. When limited to digestive tract, infection may resolve without IS reduction.

Cryptosporidium infection in solid organ transplantation

Diarrhea is a common complication in solid organ transplant (SOT) recipients and may be attributed to immunosuppressive drugs or infectious organisms such as bacteria, viruses or parasites. Cryptosporidium usually causes self-limited diarrhea in immunocompetent hosts. Although it is estimated that cryptosporidium is involved in about 12% of cases of infectious diarrhea in developing countries and causes approximately 748000 cases each year in the United States, it is still an under recognized and important cause of infectious diarrhea in SOT recipients. It may run a protracted course with severe diarrhea, fluid and electrolyte depletion and potential for organ failure. Although diagnostic methodologies have improved significantly, allowing for fast and accurate identification of the parasite, treatment of the disease is difficult because antiparasitic drugs have modest activity at best. Current management includes fluid and electrolyte replacement, reduction of immunosuppression and single therapy with Nitazoxanide or combination therapy with Nitazoxanide and other drugs. Future drug and vaccine development may add to the currently poor armamentarium to manage the disease. The current review highlights key epidemiological, diagnostic and management issues in the SOT population.

Diarrhea after kidney transplantation: a new look at a frequent symptom

Diarrhea is a frequent but overlooked complication of kidney transplantation. Diarrhea is repeatedly neglected, often considered by patients and clinicians an unavoidable side effect of immunosuppressive regimens. It is, however, associated with a significant impairment in life quality. Severe and chronic posttransplant diarrhea may lead to dehydration, malabsorption, rehospitalization, immunosuppression, noncompliance, and a greater risk of graft loss and death. There is thus a need to optimize and standardize the management of posttransplant diarrhea with consistent diagnostic and therapeutic strategies. A recent study has suggested that the increased sensitivity of molecular tools might help in early pathogen identification and guidance of antimicrobial treatment. Most bacterial and protozoan infections are readily curable with appropriate antimicrobial agents; cryptosporidiosis and C. difficile infections may however be complicated by relapsing courses. In addition, identification of enteric viral genomes in stool has further reduced posttransplant diarrhea of unknown origin. Chronic norovirus-related posttransplant diarrhea, arising from the interplay of the virus and immunosuppressive drugs, has emerged as a new challenge in the field. Prospective and controlled studies are necessary to evaluate the efficacy and safety of innovative anti-norovirus therapeutics, as well as optimal immunosuppressive regimens, to enable viral clearance while preventing rejection and donor-specific antibody formation. This review seeks to provide a basis for the design of future clinical prospective studies.

Cryptosporidium parvum induces SIRT1 expression in host epithelial cells through downregulating let-7i

Epithelial cells along human gastrointestinal mucosal surface express pathogen-recognizing receptors and actively participate in the regulation of inflammatory reactions in response to microbial infection. The NAD-dependent deacetylase sirtuin-1 (SIRT1), one member of the sirtuin family of proteins and an NAD-dependent deacetylase has been implicated in the regulation of multiple cellular processes, including inflammation, longevity, and metabolism. In this study, we demonstrated that infection of cultured human biliary epithelial cells (H69 cholangiocytes) with a parasitic protozoan, Cryptosporidium parvum, induced SIRT1 expression at the protein level without a change in SIRT1 mRNA content. Using real-time PCR and Northern blot analyses, we found that C. parvum infection decreased the expression of let-7i in infected H69 cells. Down-regulation of let-7i caused relief of miRNA-mediated translational suppression of SIRT1 and consequently, resulted in an increased SIRT1 protein level in infected H69 cell cultures. Moreover, gain- and loss-of-function studies revealed that let-7i could modulate NF-κB activation through modification of SIRT1 protein expression. Thus, our data suggest that let-7i regulates SIRT1 expression in human biliary epithelial cells in response to microbial challenge, suggesting a new role of let-7i in the regulation of NF-κB-mediated epithelial innate immune response.

Diarrhea in solid-organ transplant recipients: a review of the evidence

OBJECTIVE

To provide a comprehensive review of the literature as it relates to diarrhea in solid organ transplant (SOT) recipients. In this article, we review the epidemiology, pathogenesis, clinical manifestations, diagnosis and management of diarrhea in SOT recipients and discuss recent advances and challenges.

METHODS

Two investigators conducted independent literature searches using PubMed, Web of Science, and Scopus until January 1st, 2013. All databases were searched using a combination of the terms diarrhea, solid organ transplant, SOT, transplant associated diarrhea, and transplant recipients. Articles that discussed diarrhea in SOT recipients were reviewed and relevant cross-references also read and evaluated for inclusion. Selection bias could be a possible limitation of the approach used in selecting or finding articles for this article.

FINDINGS

Post-transplant diarrhea is a common and distressing occurrence in patients, which can have significant deleterious effects on the clinical course and well-being of the organ recipient. A majority of cases are due to infectious and drug-related etiologies. However, various other etiologies including inflammatory bowel disease must be considered in the differential diagnosis. A step-wise, informed approach to post-transplant diarrhea will help the clinician achieve the best diagnostic yield. The use of diagnostic endoscopy should be preceded by exclusion of an infectious or drug-related cause of diarrhea. Empiric management with antidiarrheal agents, probiotics, and lactose-free diets may have a role in managing patients for whom no cause can be determined even after an extensive investigation.

CONCLUSIONS

Physicians should be familiar with the common etiologies that result in post-transplant diarrhea. A directed approach to diagnosis and treatment will not only help to resolve the diarrhea but also prevent potentially life-threatening consequences including loss of the graft as well. Prospective studies are required to determine the etiology of post-transplant diarrhea in different clinical and geographic settings.

Cryptosporidiosis: An under-recognized public health problem

Cryptosporidium spp. is under recognized as an important pathogen causing diarrhea in children and HIV-infected individuals with associated high morbidity and mortality. In endemic areas, most symptomatic infections are in childhood and in immunocompromised adults. The immune status of the host plays a critical role in determining the severity of cryptosporidiosis. Infection is self-limited in immunocompetent hosts, but can be severe and persistent in the immunocompromised such as AIDS patients or malnourished children. Cryptosporidiosis in developing countries is a major cause of acute and persistent diarrhea in children and is associated with subsequent impairment in growth, physical fitness, and cognitive function. Despite recognition of the importance of immune status, the correlates of protective immunity in cryptosporidiosis in humans are poorly understood, and treatment modalities are limited.

Secondary sclerosing cholangitis: pathogenesis, diagnosis, and management

Secondary sclerosing cholangitis (SSC) is an aggressive and rare disease with intricate pathogenesis and multiple causes. Understanding the specific cause underlying each case of SSC is crucial in the clinical management of the disease. Radiologic imaging can help diagnose SSC and hence institute management in a timely manner. Management may encompass simple interventions, such as supportive therapy, antibiotics, and monitoring, or more serious measures, such as surgery, endoscopic intervention, or liver transplantation. Patients with AIDS cholangiopathy have limited therapeutic options and worsened survival. The disease should always be highly suspected in patients with primary sclerosing cholangitis with questionable diagnosis.

Parasitic infections in solid organ transplant recipients

Parasitic diseases are rare infections after a solid organ transplant (SOT). Toxoplasmosis, Trypanosoma cruzi, and visceral leishmanias are the 3 main opportunistic protozoal infections that have the potential to be lethal if not diagnosed early and treated appropriately after SOT. Strongyloides stercoralis is the one helminthic disease that is life-threatening after transplant. This review addresses modes of transmission, methods of diagnosis, and treatment of the most serious parasitic infections in SOT. The role of targeted pretransplant screening of the donor and recipient for parasitic diseases is also discussed.

Cryptosporidiosis in children following solid organ transplantation

BACKGROUND

Cryptosporidium parvum is a common cause of diarrhea. In immunocompetent individuals, spontaneous recovery is the rule. In immunocompromised patients, it may cause a serious disease. Data on cryptosporidiosis in children after solid organ transplantation are few. We report on 6 pediatric solid organ recipients with gastroenteritis caused by Cryptosporidium.

PATIENTS AND METHODS

All episodes of gastroenteritis in solid organ transplant recipients hospitalized in Schneider Children's Medical Center from January 2008 to August 2011 were identified. Data on the episodes with positive staining for Cryptosporidium antigen in stool were reviewed.

RESULTS

Fifty-seven episodes of gastroenteritis were recorded. In 6 (11%) patients (4 kidney recipient, 1 liver and kidney recipient and 1 heart transplant recipient) Cryptosporidium antigen was detected in stool. Mean age at transplantation was 3.7 ± 2 years, mean time between transplantation and cryptosporidial disease was 39 ± 53.9 months. Symptoms included prolonged diarrhea, fever, abdominal pain and weight loss. Mean duration of symptoms before diagnosis was 10.5 ± 8.7 days. In 5 children, kidney function deteriorated, blood concentrations of tacrolimus increased in 5 patients and abnormal values of liver enzymes were detected in 4 patients. All patients were hospitalized and received intravenous fluid replacement and were treated with nitazoxanide for 5-21 days. Two patients had recurrence of symptoms after short course (5 days) therapy. All patients recovered eventually from the disease.

CONCLUSION

Cryptosporidium should be routinely tested in solid organ transplant recipients with diarrhea. Delay in initiation of treatment can result in serious complications including acute renal failure. Long-term therapy with nitazoxanide (at least 14 days) may facilitate recovery.

Cryptosporidiosis: a rare and severe infection in a pediatric renal transplant recipient

Cryptosporidium is an intracellular protozoan parasite that causes gastroenteritis in human. In immunocompromised individuals, cryptosporidium causes far more serious disease. There is no effective specific therapy for cryptosporidiosis, and spontaneous recovery is the rule in healthy individuals. However, immunocompromised patients need effective and prolonged therapy. Here, we present our clinical experience in a six-yr-old boy who underwent living-related donor renal transplantation and who was infected with Cryptosporidium spp. Our patient was successfully treated with antimicrobial agents consisting of spiramycin, nitazoxanide, and paromomycin. At the end of second week of therapy, his stool became negative for Cryptosporidium spp. antigen and spiramycin was discontinued. Nitazoxanide and paromomycin treatment was extended to four wk. With this case, we want to emphasize that cryptosporidiosis should be considered in the differential diagnosis of severe or persistent diarrhea in solid organ transplant recipients where rigorous antimicrobial therapy is needed.

Parasitic infections in solid-organ transplant recipients

PURPOSE OF REVIEW

To provide an updated perspective of the most common parasitic infections occurring in solid-organ transplant (SOT) recipients.

RECENT FINDINGS

Parasitic infections are an emerging problem in SOT programs and represent a diagnostic and therapeutic challenge. Transplantation in endemic areas - including medical tourism, international travel and migration - justify the necessity of considering parasitic infections in the differential diagnosis of posttransplant complications. Molecular techniques, such as PCR, may improve the diagnostic accuracy and help during the follow-up.

SUMMARY

Parasitic infections are an uncommon but potentially severe complication in SOT recipients. An increase of donors emigrated from tropical areas and more posttransplant patients traveling to endemic areas have led to a rise in parasitic infections reported among SOT recipients. Transplant physicians should get familiar with parasitic infections and promote adherence to preventive measures in SOT recipients.

Cryptosporidium enteritis in solid organ transplant recipients: multicenter retrospective evaluation of 10 cases reveals an association with elevated tacrolimus concentrations

BACKGROUND

Cryptosporidial enteritis, a diarrheal infection of the small intestine caused by the apicomplexan protozoa Cryptosporidium, is infrequently recognized in transplant recipients from developed countries.

METHODS

A retrospective review of all cases of cryptosporidiosis in solid organ transplant (SOT) recipients at 2 centers from January 2001 to October 2010 was performed and compared with transplant recipients with community-onset Clostridium difficile infection (CDI). A literature search was performed with regard to reported cases of cryptosporidiosis in SOT recipients.

RESULTS

Eight renal, 1 liver, and 1 lung transplant recipient were diagnosed with cryptosporidiosis at median 46.0 months (interquartile range [IQR] 25.2-62.8) following SOT. Symptoms existed for a median 14 days (IQR 10.5-14.8) before diagnosis. For the 9 patients receiving tacrolimus (TAC), mean TAC levels increased from 6.3 ± 1.1 to 21.3 ± 9.2 ng/mL (P = 0.0007) and median serum creatinine increased temporarily from 1.3 (IQR 1.1-1.7) to 2.4 (IQR 2.0-4.6) mg/dL (P = 0.008). By comparison, 8 SOT recipients (6 kidney, 2 liver) hospitalized with community-onset CDI had a mean TAC level of 10.8 ± 2.8 ng/dL during disease compared with 9.2 ± 2.3 ng/mL at baseline (P = 0.07) and had no change in median creatinine. All patients recovered from Cryptosporidium enteritis after receiving various chemotherapeutic regimens.

CONCLUSIONS

Cryptosporidiosis should be recognized as an important cause of diarrhea after SOT and is associated with elevated TAC levels and acute kidney injury. Increased TAC levels may reflect altered drug metabolism in the small intestine.

Parasitic infections in solid organ transplant recipients

Parasitic infections are an uncommon but potentially severe complication in solid organ transplant (SOT) recipients. An increase in donors who have emigrated from tropical areas and more transplant recipients traveling to endemic areas have led to a rise in parasitic infections reported among SOT recipients. Clinicians should include these infections in their differential diagnosis and promote adherence to preventive measures in SOT recipients.

Cryptosporidiosis in paediatric renal transplantation

Diarrhoea in transplantation may be secondary to infectious agents and immunosuppressive drugs. The use of combined immunosuppressive drugs increases the incidence of infectious diarrhoea. We retrospectively collected all diarrhoea episodes during a 3-year period in 199 pediatric renal transplant recipients, including 47 patients receiving a kidney transplant during this period. We diagnosed 64 diarrhoea episodes (32% of the patients, 10.7% per year). Fourteen diarrhoea episodes could be attributed to the immunosuppressive treatment, and 12 remained without diagnosis. Nineteen patients (<10%) receiving mycophenolic acid (MPA) developed diarrhoea, 14 of whom had episodes attributable to the immunosuppressive treatment. Reducing the MPA dose or switching to another immunosuppressant did not induce graft rejection, if at all, for at least 6 months. Thirty-eight diarrhoea episodes were caused by infectious agents: viruses in 16 patients, bacterial agents in ten patients, Candida albicans in four cases and parasitic agents in eight cases (Giardia lambdia in one patient and Cryptosporidium in seven patients). In our cohort, Cryptosporidium was responsible for 18% of the infectious diarrhoea and 11% of all causes of diarrhoea, and it affected 3.5% of the newly transplanted patients during the 3-year study period. The clinical presentation of the disease was profuse and persistent diarrhoea with acute renal failure in all patients. We propose that oocysts be screened for in the stool during the early stages of tests for determining the origin of infectious diarrhoea. Disease treatment requires early specific treatment (nitazoxanide) for extended periods of time in conjunction with supportive rehydration.

Secondary sclerosing cholangitis

Secondary sclerosing cholangitis (SSC) is a chronic cholestatic biliary disease, characterized by inflammation, obliterative fibrosis of the bile ducts, stricture formation and progressive destruction of the biliary tree that leads to biliary cirrhosis. SSC is thought to develop as a consequence of known injuries or secondary to pathological processes of the biliary tree. The most frequently described causes of SSC are longstanding biliary obstruction, surgical trauma to the bile duct and ischemic injury to the biliary tree in liver allografts. SSC may also follow intra-arterial chemotherapy. Sclerosing cholangitis in critically ill patients is a largely unrecognized new form of SSC, and is associated with rapid progression to liver cirrhosis. The mechanisms leading to cholangiopathy in critically ill patients are widely unknown; however, the available clinical data indicate that ischemic injury to the intrahepatic biliary tree may be one of the earliest events in the development of this severe form of sclerosing cholangitis. Therapeutic options for most forms of SSC are limited, and patients with SSC who do not undergo transplantation have significantly reduced survival compared with patients with primary sclerosing cholangitis. Sclerosing cholangitis in critically ill patients, in particular, is associated with rapid disease progression and poor outcome.

Atypical p-ANCA in PSC and AIH: a hint toward a "leaky gut"?

Primary sclerosing cholangitis (PSC) and autoimmune hepatitis (AIH) are enigmatic chronic inflammatory diseases of the liver, which are frequently associated with chronic inflammatory bowel diseases. Both types of liver disease share various distinct autoantibodies such as atypical perinuclear antineutrophil cytoplasmic antibodies (p-ANCA), and thus are considered autoimmune disorders with atypical features. The discovery that atypical p-ANCA recognize both tubulin beta isoform 5 in human neutrophils and the bacterial cell division protein FtsZ has renewed the discussion on the potential role of microorganisms in the pathogenesis of both diseases. In this paper, we review the evidence for microbial infection in PSC and AIH and discuss new concepts how cross-recognition between microbial antigens in the gut and host components by the immune system along with stimulation of pattern recognition receptors might give rise to chronic hepatic inflammatory disorders with features of autoimmunity.

Cryptosporidium parvum-associated sclerosing cholangitis in a liver transplant patient

Cryptosporidium parvum causes severe long-standing diarrhea in immunocompromised patients. Sclerosing cholangitis caused by C. parvum is a rare complication in transplant recipients. We report herein the presentation of Cryptosporidium-associated cholangitis in an adult liver transplant patient diagnosed by liver biopsy. The patient improved on treatment with azithromycin and paromomycin.

Zoonoses in Solid-Organ and Hematopoietic Stem Cell Transplant Recipients

Numerous reports exist of the transmission of zoonoses to humans during and after solid-organ and hematopoietic stem cell transplantation. Donor-derived infections of numerous etiologies, including West Nile virus infection, Chagas disease, toxoplasmosis, rabies, lymphocytic choriomeningitis virus infection, and infection due to Brucella species have been reported. Most zoonoses occur as a primary infection after transplantation, and immunocompromised patients are more likely to experience significant morbidity and mortality from these infections. Risks of zoonotic infection in the posttransplantation period could be reduced by patient education. Increased recognition of the risks of zoonoses, as well as the advent of molecular biology-based testing, will potentially augment diagnostic aptitude. Documented zoonotic infection as it affects transplantation will be the primary focus of this review.

Cryptosporidiosis in a patient on PEG-interferon and ribavirin for recurrent hepatitis C after living donor liver transplantation

We report a case of a 48-year-old male who developed cryptosporidial enterocolitis while on pegylated-interferon alpha-2a and ribavirin for recurrent hepatitis C 2 years after living donor liver transplantation. He recovered after discontinuation of interferon and ribavirin and intermittent lowering of the immunosuppressant. We postulate that the myelodepressant effect of interferon and ribavirin in addition to an established immunosuppressive regimen permitted this opportunistic infection. To the best of our knowledge, this is the first case of cryptosporidiosis in a patient treated with interferon and ribavirin for recurrent hepatitis C after liver transplantation in the literature.

Severe cryptosporidiosis in a seven-year-old renal transplant recipient: case report and review of the literature

Cryptosporidium is an intracellular protozoa that can cause gastroenteritis in humans. In immunocompromised hosts, infection can be severe, leading to life-threatening persistent diarrhea. There is limited experience in treating this infection in solid organ transplants. Although newer drugs active against Cryptosporidium exist, they are only licensed in the USA for treatment of immunocompetent hosts. Here we describe a seven-year-old renal transplant recipient with severe cryptosporidiosis. He had a protracted course of diarrhea of up to 2 L/day. He was successfully managed with combination antimicrobial therapy including nitazoxanide, paromomycin, and azithromycin. In conjunction with this regimen, he had a reduction in immunosuppression and complete bowel rest. His stool pattern normalized in four weeks and he has had no recurrence after six months of follow up.

Parasitic infections in transplant recipients

Parasitic infections are important complications of organ transplantation that are often overlooked in the differential diagnosis of post-transplantation pyrexial illness. Although their frequency is unknown, they seem to be much less prevalent than bacterial and viral infections. Only 5% of human pathogenic parasites have been reported to cause significant illness in transplant recipients. Infection can occur via transmission with the graft or blood transfusion, or be acquired de novo from the environment. Recrudescence of dormant infection can lead to active disease. Post-transplantation parasitic disorders tend to cluster into two clinical profiles. First, an acute systemic illness with anemia, constitutional manifestations and variable stigmata of organ involvement; acute graft dysfunction can lead to confusion and acute rejection. Protozoa including malarial Plasmodium, Leishmania, Trypanosoma and Toxoplasma are associated with this profile. The second typical manifestation encompasses a few localized syndromes, usually associated with the lower gastrointestinal tract, caused by either protozoa (Cryptosporidium and microsporidia) or nematodes (Strongyloides and Ascaris). Dissemination of localized infections can lead to life-threatening systemic manifestations. A high index of suspicion is essential, as diagnosis requires special sampling techniques and laboratory procedures. Definitive diagnosis is usually achieved by detecting the parasite in the patient's tissues or body fluids by histological examination or culture, or by polymerase chain reaction amplification of the parasite-specific antigen sequence. Antibody detection using serological techniques is also possible in a few parasitic infections. Certain lesions have characteristic radiological appearances, hence the value of imaging, particularly in the cerebral syndromes. Treatment is usually straightforward (broad spectrum or specific drugs), yet some species are drug resistant.

Infection with Cryptosporidium hominis and reinfection with Cryptosporidium parvum in a transplanted ileum

A transplanted ileum was found to be infected with Cryptosporidium hominis 6 days after transplantation. Although the infection resolved, the ileum was later found to be infected with Cryptosporidium parvum. The presence of the parasite was not always correlated with diarrhea. No other gastrointestinal symptom was ever detected. Treatment with azithromycin and paromomycin apparently failed.

Reversible sclerosing cholangitis secondary to cryptosporidiosis in a renal transplant patient

Cryptosporidium parvum is a well-known cause of chronic diarrhea. In human immunodeficiency virus (HIV)-infected patients as well as in other immunocompromised patients it has also been shown to cause sclerosing cholangitis. We report a case of reversible C. parvum-induced sclerosing cholangitis in a renal transplant patient. This 40-year-old female received a renal transplant 9 years prior to presentation. She had no history of liver disease and was doing well on tacrolimus, prednisone, and azathioprine. She developed diarrhea and was found to have C. parvum present in the stool. Shortly after, she developed clinical, biochemical, radiologic, and histologic features of SC. After accidental reduction in her immunesuppression secondary to starting her on rifampin to treat her itching, she cleared C. parvum from her stool and had a marked improvement in her diarrhea, jaundice, and general health. Her liver enzymes normalized and magnetic resonance cholangiography showed complete resolution of biliary abnormalities. To our knowledge, this is the first case of C. parvum-induced sclerosing cholangitis in a renal transplant patient and one of a few in non-HIV patients. It is also the first to document resolution of sclerosing cholangitis after eradication of C. parvum in a non-HIV patient.

Epidemiology and clinical features of Cryptosporidium infection in immunocompromised patients

Cryptosporidium spp. are a major cause of diarrheal disease in both immunocompetent and immunodeficient individuals. They also cause waterborne disease in both the United States and United Kingdom. Studies on the mechanisms of immunity to cryptosporidiosis indicate the importance of the T-cell response. The spectrum and severity of disease in immunocompromised individuals with cryptosporidiosis reflect this importance since the most severe disease is seen in individuals with defects in the T-cell response. The most commonly studied group is that of patients with AIDS. These patients suffer from more severe and prolonged gastrointestinal disease that can be fatal; in addition, body systems other than the gastrointestinal tract may be affected. The widespread use of antiretroviral therapy does appear to be having a beneficial effect on recovery from cryptosporidiosis and on the frequency of infection in human immunodeficiency virus-positive patients. Other diseases that are associated with increased risk of severe cryptosporidiosis, such as primary immunodeficiencies, most notably severe combined immunodeficiency syndrome, are also predominantly associated with T-cell defects. Of the remaining groups, children with acute leukemia seem to be most at risk from cryptosporidiosis. There is less evidence of severe complications in patients with other malignant diseases or in those receiving immunosuppressive chemotherapy.