Etiology and outcome of diarrhea after marrow transplantation: a prospective study

Diagnostic performance of a multiplexed gastrointestinal PCR panel for identifying diarrheal pathogens in children undergoing hematopoietic stem cell transplant

BACKGROUND

Diarrhea is a common complication of hematopoietic stem cell transplantation (HSCT) and is associated with substantial morbidity, but its etiology is often unknown. Etiologies of diarrhea in this population include infectious causes, chemotherapy- or medication-induced mucosal injury and graft-versus-host disease (GVHD). Distinguishing these potential causes of diarrhea is challenging since diarrheal symptoms are often multifactorial, and the etiologies often overlap in transplant patients. The objectives of this study were to evaluate whether the FilmArray gastrointestinal (GI) panel would increase diagnostic yield and the degree to which pre-transplantation colonization predicts post-transplantation infection.

METHODS

From November 2019 to February 2021, a total of 158 patients undergoing HSCT were prospectively included in the study. Stool specimens were obtained from all HSCT recipients prior to conditioning therapy, 28 ± 7 days after transplantation and at any new episode of diarrhea. All stool samples were tested by the FilmArray GI panel and other clinical microbiological assays.

RESULTS

The primary cause of post-transplantation diarrhea was infection (57/84, 67.86%), followed by medication (38/84, 45.24%) and GVHD (21/84, 25.00%). Ninety-five of 158 patients were colonized with at least one gastrointestinal pathogen before conditioning therapy, and the incidence of infectious diarrhea was significantly higher in colonized patients (47/95, 49.47%) than in non-colonized patients (10/63, 15.87%) (P < 0.001). Fourteen of 19 (73.68%) patients who were initially colonized with norovirus pre-transplantation developed a post-transplantation norovirus infection. Twenty-four of 62 (38.71%) patients colonized with Clostridium difficile developed a diarrheal infection. In addition, FilmArray GI panel testing improved the diagnostic yield by almost twofold in our study (55/92, 59.78% vs. 30/92, 32.61%).

CONCLUSIONS

Our data show that more than half of pediatric patients who were admitted for HSCT were colonized with various gastrointestinal pathogens, and more than one-third of these pathogens were associated with post-transplantation diarrhea. In addition, the FilmArray GI panel can increase the detection rate of diarrheal pathogens in pediatric HSCT patients, but the panel needs to be optimized for pathogen species, and further studies assessing its clinical impact and cost-effectiveness in this specific patient population are also needed.

How I approach diarrhea in hematological transplant patients: A practical tool

Diarrhea in hematopoietic stem-cell transplantation (HSCT) remains a multifactorial challenge that demands a nuanced diagnostic approach. The causes of infectious diarrhea in HSCT recipients are diverse and influenced by patient-specific risk factors, the post-transplant timeline, and local epidemiology. During the past decade, our understanding of diarrhea in HSCT has witnessed a transformative shift through the incorporation of gastrointestinal (GI) multiplex polymerase chain reaction (PCR) panels. However, the judicious application of these panels is imperative to avoid overtesting and prevent adverse outcomes. The challenge lies in distinguishing between the diverse causes of diarrhea, ascertaining the clinical significance of detected pathogens, and navigating the diagnostic uncertainty presented by several non-infectious conditions such as mucositis, intestinal dysbiosis, and acute graft-versus-host disease (aGvHD), all of which mimic infection. This review examines the landscape of infectious diarrhea in the HSCT population, encompassing both established (e.g., Cytomegalovirus, Clostridioides difficile, and norovirus) and emerging pathogens (e.g., sapoviruses, astroviruses). We propose a multifaceted diagnostic algorithm that combines clinical assessment, risk stratification, and tailored utilization of molecular platforms. While multiplex GI panels present invaluable opportunities for rapid and comprehensive pathogen detection, their judicious use is pivotal in preserving diagnostic stewardship. Customization of diagnostic algorithms tailored to local epidemiology ensures optimal patient care and resource utilization.

Mycophenolate mofetil increases the risk of diarrhea in allogeneic hematopoietic stem cell transplantation recipients

OBJECTIVES

Mycophenolate mofetil (MMF) was reported to be a main cause of diarrhea following organ transplantation. However, research on MMF-induced diarrhea following allogeneic hematopoietic stem cell transplantation (allo-HSCT) is currently insufficient. This retrospective study examined the incidence of MMF-induced diarrhea among allo-HSCT recipients.

METHODS

Recipients were divided according to the receipt of MMF and the appearance of diarrhea. The differences in clinical information, MMF usage and trough concentrations, and the occurrence of diarrhea from the first day of conditioning treatment to 100 days after transplantation were analyzed.

RESULTS

In total, 32.9% of the recipients reported diarrhea. The incidence rate of diarrhea was higher in the MMF group than in the non-MMF group (40.0% vs. 16.7%). MMF-induced diarrhea usually occurred within 9 days of MMF initiation and persisted for 7.27 ± 3.54 days. The average body weight, MMF daily dose, and MMF trough concentration were higher in patients with diarrhea.

CONCLUSION

MMF increased the risk of diarrhea in allo-HSCT recipients, and the risk was related to the MMF dose and trough concentration. The difference in onset time could be a basis for identifying the cause of diarrhea in allo-HSCT recipients.

Diagnostic yield for video capsule endoscopy in gastrointestinal graft- versus -host disease: a systematic review and metaanalysis

BACKGROUND

The gastrointestinal tract is the second most involved organ for graft-versus-host disease where involvement of the small intestine is present in 50% of the cases. Therefore, the use of a non-invasive investigation i.e., video capsule endoscopy (VCE) seems ideal in the diagnostic work-up, but this has never been systematically evaluated before.

OBJECTIVE

The aim of this systematic review was to determine the efficacy and safety of VCE, in comparison with conventional endoscopy in patients who received hematopoietic stem cell transplantation.

METHOD

Databases searched were PubMed, Scopus, EMBASE, and Cochrane CENTRAL. All databases were searched from their inception date until June 17, 2022. The search identified 792 publications, of which 8 studies were included in our analysis comprising of 232 unique patients. Efficacy was calculated in comparison with the golden standard i.e., histology. Risk of bias assessment was performed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool.

RESULTS

The pooled sensitivity was higher for VCE at 0.77 (95% CI: 0.60-0.89) compared to conventional endoscopy 0.62 (95% CI: 0.47-0.75) but the difference was not statistically significant (p = 0.155, Q = 2.02). Similarly, the pooled specificity was higher for VCE at 0.68 (95% CI: 0.46-0.84) than for conventional endoscopy at 0.58 (95% CI: 0.40-0.74) but not statistically significant (p = 0.457, Q = 0.55). Moreover, concern for adverse events such as intestinal obstruction or perforation was not justified since none of the capsules were retained in the small bowel and no perforations occurred in relation to VCE. A limitation to the study is the retrospective approach seen in 50% of the studies.

CONCLUSION

The role of video capsule endoscopy in diagnosing or dismissing graft-versus-host disease is not yet established and requires further studies. However, the modality appears safe in this cohort.

Acute graft-versus-host disease

Acute graft-versus-host disease (GVHD) is a common immune complication that can occur after allogeneic haematopoietic cell transplantation (alloHCT). Acute GVHD is a major health problem in these patients, and is associated with high morbidity and mortality. Acute GVHD is caused by the recognition and the destruction of the recipient tissues and organs by the donor immune effector cells. This condition usually occurs within the first 3 months after alloHCT, but later onset is possible. Targeted organs include the skin, the lower and upper gastrointestinal tract and the liver. Diagnosis is mainly based on clinical examination, and complementary examinations are performed to exclude differential diagnoses. Preventive treatment for acute GVHD is administered to all patients who receive alloHCT, although it is not always effective. Steroids are used for first-line treatment, and the Janus kinase 2 (JAK2) inhibitor ruxolitinib is second-line treatment. No validated treatments are available for acute GVHD that is refractory to steroids and ruxolitinib, and therefore it remains an unmet medical need.

Blastocystis sp.-An emerging cause of diarrhea post stem cell transplantation

Key Clinical Message

Protozoans are endemic in the Middle East and diarrhea workup post stem cell transplant should always include stool examination for ova and parasites.

Abstract

We present a case of Blastocystis sp. infection in a multiple myeloma patient who developed diarrhea on day five of post-autologous stem cell transplantation. Diarrhea is a major complication and a potential cause of mortality in this population. Testing for endemic protozoan is recommended.

Viable Bifidobacterium tablets for the prevention of chemotherapy-/radiation-induced mucositis in patients undergoing haematopoietic stem cell transplantation

PURPOSE

Mucositis is a frequent and severe complication in haematopoietic stem cell transplantation (HSCT). The effectiveness of probiotics in mucositis has been indicated by several clinical trials, but the results are still controversial. To date, studies on the influence of probiotics in HSCT are limited. Therefore, we conducted this retrospective study to evaluate the impact of viable Bifidobacterium tablets on the incidence and duration of chemotherapy-/radiation-induced mucositis in patients undergoing HSCT.

METHODS

Clinical data of 278 patients who underwent HSCT between May 2020 and November 2021 were retrospectively analysed. They were divided into a control group (138) and a probiotic group (140) according to whether they took viable Bifidobacterium tablets. First, we analysed the baseline data of the two groups. Then, we compared the incidence, severity and duration of mucositis between the two groups by using Mann-Whitney U test, chi-square test and Fisher's exact test according to the type of data. In order to exclude the influence of confounding factors, we further evaluated the efficacy of oral probiotics in preventing oral mucositis by Binary logistic regression analysis.

RESULTS

The use of viable Bifidobacterium tablets markedly reduced the incidence of oral mucositis (OM) (62.9% vs. 81.2%, p = 0.001) and mainly reduced the incidence of grades 1-2 OM (74.6% vs. 58.6%, p = 0.005). There was no significant difference in the incidence of severe (grades 3-4) OM between the two groups (6.5% vs. 4.3%, p = 0.409). The median duration of OM was shorter in the probiotic group (10 vs. 12 days, p = 0.037). The incidence and duration of diarrhoea did not differ between the two groups. Moreover, the use of viable Bifidobacterium tablets had no influence on engraftment.

CONCLUSIONS

Our results suggested that viable Bifidobacterium tablets could effectively reduce the incidence of grades 1-2 OM and duration of OM during the transplant process without affecting the outcome of HSCT.

Infectious diarrhea after allogeneic hematopoietic cell transplantation assessed by a multiplex polymerase chain reaction assay

OBJECTIVES

To determine the incidence of infectious diarrhea after allogeneic hematopoietic cell transplantation (HCT) using a multiplex polymerase chain reaction assay and assess risk factors for developing infectious diarrhea.

METHODS

This was a single-center retrospective study of 140 consecutive allogeneic HCT recipients. Infectious diarrhea was assessed using a laboratory-developed multiplex polymerase chain reaction the first year after transplantation.

RESULTS

The incidence rate of infectious diarrhea episodes was 47 per 100 person-years, with the highest rate observed in the pre-engraftment phase. Most episodes were seen as nosocomial infections (38%) and most affected patients (82%) had only one episode of infectious diarrhea. The cumulative incidence of at least one episode of infectious diarrhea was 32% after 1 year. Nonrelapse mortality was higher in transplant recipients with at least one episode of infectious diarrhea (hazard ratio (HR) 2.02, 95% CI = 1.07-3.80). The most frequently observed pathogens were Clostridium difficile, adenovirus, Enteropathogenic Escherichia coli, and Campylobacter jejuni. Patients with acute lower gastrointestinal graft-vs-host disease stage 3 or 4 (HR 3.68, 95% CI = 1.57-8.63) conferred a higher risk for a first infectious diarrhea episode.

CONCLUSION

Infectious diarrhea after allogeneic HCT was seen in about one-third of the patients, mostly as nosocomial infection in the pre-engraftment phase.

Gastrointestinal Complications after Allogeneic Hematopoietic Stem Cell Transplant: A Multidisciplinary Approach with Early Endoscopic Evaluation

Gastrointestinal complications (GICs) represent the major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Differential diagnosis of GICs is of paramount importance since early and reliable identification of graft-versus-host disease (GVHD) is essential for a correct management of the patients. The aim of the present retrospective study was to evaluate the occurrence of GICs after allo-HSCT and to assess the diagnostic performance of a quick endoscopic and histological assessment in the differential diagnosis between GVHD and other GI conditions. Between January 2015 and August 2019, 122 consecutive patients receiving an allo-HSCT were managed by an interdisciplinary team, supported by a dedicated endoscopic service. Clinical, therapeutic, endoscopic and histological data were analyzed for each patient. Collectively, 94 of the patients developed GICs (77%). A moderate–severe mucositis was the most frequent complication, occurring in 79 patients (84%). Acute GI-GVHD was diagnosed in 35 patients (37% of whom with GICs) and 19 of them with a moderate–severe grade. Infective acute colitis developed in eight patients, mainly due to Clostridium difficile (CD) and Cytomegalovirus infections (8.5%). Rectal biopsy showed the highest sensitivity and specificity (80% and 100%, respectively). However, when biopsy procedures were guided by symptoms and performed on apparently intact mucosa, upper histology also provided a high negative predictive value (80%). Our multidisciplinary approach with a quick endoscopic/histologic investigation in the patients receiving an allo-HSCT and who suffered GICs could improve diagnostic and therapeutic management in this challenging setting.

Mantle Cell Lymphoma Presenting as Diarrhea in a Liver Transplant Recipient

We present a 63-year-old man with a medical history of hepatocellular carcinoma who underwent orthotopic liver transplant 10 years prior on long-term immunosuppressive therapy. The patient presented to the clinic with diarrhea, and the workup revealed mantle cell lymphoma. Mantle cell lymphoma is an extremely rare finding in transplanted livers. It is essential to include mantle cell lymphoma, along with a broad differential, during the workup of diarrhea in post-transplant patients.

Viral Acute Gastroenteritis in Special Populations

Viral acute gastroenteritis (AGE) is common and afflicts people of all ages. Nonviral causes of AGE are less common. Norovirus is a leading cause of sporadic cases and outbreaks of AGE across all ages. Universal rotavirus vaccination of infants has reduced frequency and severity of rotavirus AGE cases in children and indirectly reduced cases in older adults. Severe illness is more likely in persons at age extremes or with immunocompromising conditions. Viral causes of AGE can lead to protracted diarrheal illness in immunocompromised persons. Nucleic acid amplification tests are changing diagnostic testing algorithms.

Impact of a Multiplexed Polymerase Chain Reaction Panel on Identifying Diarrheal Pathogens in Hematopoietic Cell Transplant Recipients

BACKGROUND

Diarrhea is common and associated with substantial morbidity among hematopoietic cell transplant (HCT) recipients, but the etiology is often not identified. Multiplexed polymerase chain reaction (PCR) assays increase the detection of diarrheal pathogens, but the impact of this technology in this population has not been evaluated.

METHODS

Our center replaced stool cultures and other conventional microbiologic methods with the FilmArray Gastrointestinal Panel (GI PCR) in June 2016. We reviewed all adult patients who received an HCT from June 2014-May 2015 (pre-GI PCR, n = 163) and from June 2016-May 2017 (post-GI PCR, n = 182) and followed them for 1 year after transplantation. Clostridioides difficile infection was diagnosed by an independent PCR test in both cohorts.

RESULTS

The proportion of patients with ≥1 identified infectious diarrheal pathogen increased from 25% to 37% after implementation of GI PCR (P = .01). Eight patients (5%) in the pre-GI PCR cohort tested positive for a pathogen other than C. difficile versus 49 patients (27%) in the post-GI PCR cohort (P < .001). The most common non-C. difficile diarrheal pathogens in the post-GI PCR cohort were enteropathogenic Escherichia coli (n = 14, 8%), norovirus (n = 14, 8%), and Yersinia enterocolitica (n = 7, 4%). The percentage of diarrheal episodes with an identified infectious etiology increased from 14% to 23% (P = .001). Median total costs of stool testing per patient did not increase (pre: $473; post: $425; P = .25).

CONCLUSIONS

Infectious etiologies of diarrhea were identified in a higher proportion of HCT recipients after replacing conventional stool testing with a multiplexed PCR assay, without an increase in testing costs.

Predictors of a short hospitalization in bone marrow transplantation patients presenting to the emergency department

BACKGROUND

Despite the advantages of bone marrow transplantation (BMT), patients receiving this intervention visit the emergency department (ED) frequently and for various reasons. Many of those ED visits result in hospitalization, and the length of stay varies.

OBJECTIVES

The objective of our study was to identify the patients who were only briefly hospitalized and were thus eligible for safe discharge from the ED.

METHODS

This was a retrospective cohort study conducted on all adult patients who have completed a successful BMT and had an ED visit that resulted in hospitalization.

RESULTS

Our study included 115 unique BMT with a total number of 357 ED visits. Around half of those visits resulted in a short hospitalization. We found higher odds of a short hospitalization among those who have undergone autologous BMT (95%CI [1.14-2.65]). Analysis of the discharge diagnoses showed that patients with gastroenteritis were more likely to have a shorter hospitalization in comparison to those diagnosed with others (95%CI [1.10-3.81]). Furthermore, we showed that patients who presented after a month from their procedure were more likely to have a short hospitalization (95%CI [1.04-4.87]). Another significant predictor of a short of hospitalization was the absence of Graft versus Host Disease (GvHD) (95%CI [2.53-12.28]). Additionally, patients with normal and high systolic blood pressure (95%CI [2.22-6.73] and 95%CI [2.81-13.05]; respectively), normal respiratory rate (95%CI [2.79-10.17]) and temperature (95%CI [2.91-7.44]) were more likely to have a shorter hospitalization, compared to those presenting with abnormal vitals. Likewise, we proved higher odds of a short hospitalization in patients with a quick Sepsis Related Organ Failure Assessment score of 1-2 (95%CI [1.29-5.20]). Moreover, we demonstrated higher odds of a short hospitalization in patients with a normal platelet count (95%CI [1.39-3.36]) and creatinine level (95%CI [1.30-6.18]).

CONCLUSION

In our study, we have shown that BMT patients visit the ED frequently and many of those visits result in a short hospitalization. Our study showed that patients presenting with fever/chills are less likely to have a short hospitalization. We also showed a significant association between a short hospitalization and BMT patients without GvHD, with normal RR, normal T °C and a normal platelet count.

Diarrheal Morbidity During Hematopoietic Cell Transplantation: The Diagnostic Yield of Stool Cultures

INTRODUCTION

Diarrhea affects a significant proportion of patients undergoing hematopoietic cell transplantation (HCT). We explored the diagnostic yield of stool cultures for enteric pathogens among patients undergoing HCT.

METHODS

This is a single-center, retrospective study. Between 5/2007 and 4/2020, consecutive patients who underwent HCT were included if inpatient bacterial stool cultures were collected. Patient characteristics, results, and timing of stool cultures obtained during hospitalization were collected.

RESULTS

A total of 1072 individuals underwent autologous (n = 603) and allogeneic (n = 469) HCT. Overall, 947 stool culture samples were obtained from 561 (52%) patients with diarrheal illness during hospitalization for HCT. Most (99%) samples were obtained beyond 3 days of admission, mainly (77%) during neutropenia. Overall, only four (0.42%) (autologous, n = 3; allogeneic, n = 1) patients had a positive stool culture and in all cases Campylobacter spp. were the pathogens identified. The number of stool cultures needed-to-test to diagnose one case of bacterial infection was 237. The cost of diagnosing one case of bacterial diarrhea was US $8770. Patients with a positive stool culture did not have discerning characteristics.

CONCLUSIONS

In our experience, the yield of stool cultures for enteropathogens in patients undergoing HCT is extremely low and thus should be avoided in most cases.

Colonic complications following human bone marrow transplantation

Background Human bone marrow transplantation (BMT) becomes an accepted treatment of leukemia, aplastic anemia, immunodeficiency syndromes, and hematologic malignancies. Colorectal surgeons must know how to determine and manage the main colonic complications.

Objective To review the clinical features, clinical and pathological staging of graft vs host disease (GVHD), and treatment of patients suffering with colonic complications of human bone marrow transplantation.

Patients and methods We have reviewed the records of all patients that received an allogeneic bone marrow transplant and were evaluated at our Colon and Rectal Surgery department due to gastrointestinal symptoms, between January 2007 and January 2012. The study was carried out in patients who developed colonic complications, all of them with clinical, histopathological or laboratory diagnosis.

Results The study group was constituted by 77 patients, 43 male and 34 female patients. We identified colonic complications in 30 patients (38.9%); five patients developed intestinal toxicity due to pretransplant chemotherapy (6.4%); graft vs. host disease was present in 16 patients (20%); 13 patients (16.8%) developed acute colonic GVHD, and 3 (3.8%) chronic GVHD. Infection was identified in 9 patients (11.6%).

Conclusions The three principal colonic complications are the chemotherapy toxicity, GVHD, and superinfection; the onset of symptoms could help to suspect the type of complication (0–20 day chemotherapy toxicity, 20 and more GVHD), and infection could appear in any time of transplantation.

Giardia lamblia mimicking acute graft versus host disease after allogeneic hematopoietic stem cell transplantation: A case report

RATIONALE

As the major complications post allogeneic hematopoietic stem cell transplantation (allo-HSCT), gastrointestinal disorders were most commonly ascribed to acute graft-versus-host disease (aGVHD) and opportunistic infections. Though Giardia lamblia (G lamblia) is the most common waterborne parasite of intestinal infection worldwide, seldom has it been reported in a patient with acute severe aplastic anemia after allo-HSCT.

PATIENT CONCERNS

A 23-year-old male with severe aplastic anemia developed diarrhea, abdominal cramps, bloating, nausea, vomiting, fever, weight loss, and fatigue after allo-HSCT.

DIAGNOSIS

Stool examinations for ova and parasites showed Giardia trophozoites and cysts.

INTERVENTIONS

Methylprednisolone was stopped and the patient was intravenously treated with a 7-day course of metronidazole (500 mg, tid.). Simultaneously, cyclosporine (5 mg/kg) was continually utilized for suspicious gut GVHD.

OUTCOMES

The Giardia lamblia in stool turned negative and his symptoms were resolved after the 7-day course.

LESSONS

Incorporating non-invasive monitoring of stool examination for ova and parasites in the follow-up algorithm for post-HSCT patients can expedite clinical decision-making in the differential diagnoses for aGVHD even in the non-endemic area. Metronidazole therapy can be well-tolerated in HSCT patients with giardiasis.

Newer approaches in diagnosis of diarrhea in immunocompromised patients

PURPOSE OF REVIEW

This review will focus on the epidemiology and cause of diarrheal illness in solid organ transplant and stem-cell transplant population recipients with a specific focus on the role of advanced multiplex technology in the diagnosis of diarrhea within this patient population.

RECENT FINDINGS

A wide range of infectious and noninfectious causes of diarrhea have been described in immunocompromised patients. The most common infections noted are Clostridioides difficile, norovirus, and cytomegalovirus, whereas immunosuppressive drugs and mucositis are the most common noninfectious causes of diarrhea. Historically, diagnostic evaluation has been limited to an array of single pathogen assays. Newer multiplex assays have become available that allow rapid, sensitive detection of a wide range of pathogens in a single assay. These assays have improved the number of patients with a diagnosed pathogen but may identify colonizing pathogens that are not pathogenic. Studies are needed to inform the discrimination and optimal use of these newer assays.

SUMMARY

Diarrhea is a common complication in immunocompromised patients and is associated with greater morbidity and rare mortality. New diagnostics facilitate detection of recognized pathogens and may allow for improved outcomes through the use of pathogen-targeted therapy.

Cross-sectional study of the prevalence, causes and management of hospital-onset diarrhoea

BACKGROUND

The National Health Service in England advises hospitals collect data on hospital-onset diarrhoea (HOD). Contemporaneous data on HOD are lacking.

AIM

To investigate prevalence, aetiology and management of HOD on medical, surgical and elderly-care wards.

METHODS

A cross-sectional study in a volunteer sample of UK hospitals, which collected data on one winter and one summer day in 2016. Patients admitted ≥72 h were screened for HOD (definition: ≥2 episodes of Bristol Stool Type 5-7 the day before the study, with diarrhoea onset >48 h after admission). Data on HOD aetiology and management were collected prospectively.

FINDINGS

Data were collected on 141 wards in 32 hospitals (16 acute, 16 teaching). Point-prevalence of HOD was 4.5% (230/5142 patients; 95% confidence interval (CI) 3.9-5.0%). Teaching hospital HOD prevalence (5.9%, 95% CI 5.1-6.9%) was twice that of acute hospitals (2.8%, 95% CI 2.1-3.5%; odds ratio 2.2, 95% CI 1.7-3.0). At least one potential cause was identified in 222/230 patients (97%): 107 (47%) had a relevant underlying condition, 125 (54%) were taking antimicrobials, and 195 (85%) other medication known to cause diarrhoea. Nine of 75 tested patients were Clostridium difficile toxin positive (4%). Eighty (35%) patients had a documented medical assessment of diarrhoea. Documentation of HOD in medical notes correlated with testing for C. difficile (78% of those tested vs 38% not tested, P<0.001). One-hundred and forty-four (63%) patients were not isolated following diarrhoea onset.

CONCLUSION

HOD is a prevalent symptom affecting thousands of patients across the UK health system each day. Most patients had multiple potential causes of HOD, mainly iatrogenic, but only a third had medical assessment. Most were not tested for C. difficile and were not isolated.

The Effects of Fecal Donors with Different Feeding Patterns on Diarrhea in a Patient Undergoing Hematopoietic Stem Cell Transplantation

Almost 90% of patients undergoing hematopoietic stem cell transplantation (HSCT) experience diarrheal episodes, which represent a severe, often life-threatening complication for these patients. Although fecal microbiota transplantation (FMT) represents an alternative treatment option for infection-related diarrhea, the application of FMT in HSCT patients is greatly restricted for safety reasons. Furthermore, the therapeutic outcomes of FMT as a diarrhea treatment are somewhat related to the choice of the FMT donor. Here, we comprehensively profiled the dynamic changes in the intestinal microbiota after FMT from two donors with different feeding patterns and the same severely diarrheal recipient undergoing HSCT via a 45-day clinical observation. Importantly, no adverse events attributed to FMT were observed. The stool volume and frequency of the patient were reduced when we used feces from donor #1 (mixed feeding), but these changes were not observed after FMT from donor #2 (exclusive breastfeeding). Interestingly, no obvious differences in overall diversity (Shannon) or richness (Chao1) between the two donors were observed. Additionally, Bifidobacterium accounted for 29.9% and 18.1% of OTUs in the stools of donors #1 and #2, respectively. Lactobacillus accounted for 16.3% and 2.9% of the stools of donors #1 and #2, respectively. Furthermore, through longitudinal monitoring of the patient, we identified 6 OTUs that were particularly sensitive to the different FMT complements. Together, we present a case report suggesting that the overall diversity of the intestinal microbiota may not be the only important element in the selection of an effective FMT donor.

A survey on incidence and management of adenovirus infection after allogeneic HSCT

To determine the current practices on the management of Adenovirus (ADV) infection after allogenic stem cell transplantation, a survey was undertook among EBMT centres. The response rate was 20% (91/446): 46% were adult, 44% were paediatric and 10% were mixed centres, respectively. The overall incidence of ADV infection was 7.1%: 4.1% in adult, 15.4% in paediatric, and 3.6% in mixed population. The determination of ADV-DNA in biological samples was used in 96% of centres; 58% of them monitored asymptomatic patients with a frequency of twice a week in 9%, once a week in 45%, every two weeks in 4% of centres. The treatment of ADV infection was mainly based on the administration of cidofovir (87%), being the schedule of 5 mg/kg/week with probenecid the most used, and the reduction of immunosuppression (84%). The threshold of ADV-DNAemia to start cidofovir in high-risk patients was most frequently >1000 copies/ml. Innovative treatments, such as brincidofovir and adoptive ADV-cytotoxic-T-lymphocytes, were used in 27% and 20% of centres, respectively. Almost all responding centres consider ADV infection serious enough to deserve testing asymptomatic or symptomatic patients. Cidofovir and reduction of immunosuppression represent the main therapeutic options but one fourth of responding centres experimented novel therapies.

Site specific diagnostic yield of endoscopic biopsies in Gastrointestinal Graft-versus-Host Disease: A tertiary care Center experience

BACKGROUND

Gastrointestinal (GI) graft versus host disease (GVHD) occurs in up to 40% of patients undergoing allogenic hematopoietic stem cell transplantation (HSCT). However, the optimal endoscopic approach is still unclear and the area of the GI tract with the highest diagnostic yield is still a topic of debate.

OBJECTIVE

We compared the diagnostic yield of different anatomic site biopsies in the diagnosis of GI GVHD and assessed the correlation of endoscopic findings with histopathology.

METHODS

All cases of biopsy proven GI GVHD were obtained from pathology database AUBMC between 1/1/2005 and 31/8/2017. We retrospectively analyzed the demographical, clinical and endoscopic data.

RESULTS

Nineteen patients were diagnosed with GI GVHD over 17.6 years. The most common presenting symptom was severe diarrhea (18 patients, 94.7%). Combining upper endoscopy and sigmoidoscopy with biopsies had the highest diagnostic yield of 90% in diagnosing GI GVHD compared to 63.6%, 78.6% and 77.8% for upper endoscopy, sigmoidoscopy and colonoscopy respectively. In macroscopically normal mucosa, the recto-sigmoid and duodenal biopsies had the highest diagnostic yield (75%). As for the macroscopically abnormal mucosa, the highest yield was for the recto-sigmoid biopsies (100%) in lower endoscopy and duodenal biopsies in the upper endoscopy (60%).

CONCLUSION

In a patient suspected to have GI GVHD, the best endoscopic approach is the combination of upper endoscopy and flexible sigmoidoscopy with biopsies of normal as well as abnormal mucosa. It should be emphasized that normal mucosa be biopsied especially in the duodenum and recto-sigmoid for a better diagnostic yield.

Detection of cytomegalovirus DNA in fecal samples in the diagnosis of enterocolitis after allogeneic stem cell transplantation

BACKGROUND

Cytomegalovirus enterocolitis is a rare but potentially life threatening complication after allogeneic stem cell transplantation. Its early diagnosis and treatment are essential for a successful outcome.

OBJECTIVE

To determine the potential benefit of fecal CMV DNA detection in the diagnosis of CMV colitis among stem cell transplant recipients.

STUDY DESIGN

Biopsies from the lower gastrointestinal tract, taken during 69 episodes of diarrhea, were compared with fecal samples previously examined for CMV DNA in 45 patients after allogeneic stem cell transplantation.

RESULTS

Six confirmed cases of CMV colitis were observed, with 16 out of 69 (23%) fecal samples proving positive for CMV DNA. Only one positive sample correlated with histologically confirmed CMV colitis, and 15 samples were evaluated as false positive. These results provide a 16.7% sensitivity and 76.2% specificity in the diagnosis of CMV enterocolitis.

CONCLUSION

The examination of fecal samples for the presence of CMV DNA has very low potential in the diagnosis of CMV enterocolitis after allogeneic stem cell transplantation; therefore, a biopsy of the gastrointestinal mucosa is still warranted for correct diagnosis.

Clinicopathological comparison between acute gastrointestinal-graft-versus-host disease and infectious colitis in patients after hematopoietic stem cell transplantation

The aim of this study is to elucidate the differences of the clinicopathological characteristics between acute gastrointestinal (GI)-graft-versus-host disease (GVHD) and infectious colitis (IC) after hematopoietic stem cell transplantation (HSCT). Of the 282 patients who underwent HSCT at our institution between January 1991 and December 2015, we could investigate 182 patients in detail. Of the 182 patients, we selected those who underwent colonoscopy and were diagnosed with acute GI-GVHD or IC after HSCT. Patients’ backgrounds, colonoscopic findings, and pathological findings were retrospectively analyzed. There were 30 patients who had colonoscopy performed and diagnosed with acute GI-GVHD or IC after HSCT. Of the 30 patients, 20 had acute GI-GVHD and 10 had IC. All the cases of acute GI-GVHD were diagnosed by endoscopic biopsy and 4 of the IC patients had Clostridium difficile associated colitis. In the IC group, the period from the transplantation up to diagnosis was significantly shorter than acute GI-GVHD group (10.0 days vs. 43.2 days, p = 0.03). In the acute GI-GVHD group, tortoiseshell-like mucosal patterns were significantly more common than the IC group (70% vs. 0%, p < 0.001). Furthermore, there were some cases presenting normal mucosal appearance despite the diagnosis with acute GI-GVHD by pathological findings. Clinically, we should consider IC when abdominal symptoms appeared in the early period after HSCT. Endoscopically, tortoiseshell-like mucosal pattern was a characteristic feature of acute GI-GVHD. In addition, it is essential to perform mucosal biopsy for diagnose of acute GI-GVHD even in patients showing the normal mucosal appearance.

Villous atrophy in the terminal ileum is a specific endoscopic finding correlated with histological evidence and poor prognosis in acute graft-versus-host disease after allo-hematopoietic stem cell transplantation

Background

Graft-versus-host disease (GVHD) is a common complication of allo-hematopoietic stem cell transplantation (allo-HSCT). Endoscopic biopsy can provide a definitive diagnosis, but the optimal endoscopic approach for diagnosis remains uncertain. This study evaluated whether ileocolonoscopic imaging can predict acute GVHD severity after allo-HSCT.

Methods

Consecutive patients who underwent allo-HSCT were referred to our institution, and those diagnosed with acute GVHD by pathology were included in this retrospective study.

Results

Fifty-one of 261 patients who underwent ileocolonoscopy were suspected to have acute intestinal GVHD. We performed univariate and multivariate conditional logistic regression with stepwise variable selection; villous atrophy in the terminal ileum remained a statistically significant predictor of GVHD severity (odds ratio, 4.69; 95% confidence interval, 1.07–20.60, P = 0.04). Patients were classified into three groups based on ileal endoscopic findings in the terminal ileum: group S, GVHD with severe villous atrophy; group M, mild atrophy; and group N, no atrophy. Compared with patients in groups M and N, those in group S had significant clinical GVHD at diagnosis (P = 0.03). In group S, three of four, compared with five of 13 patients in groups M and N, required the addition of second-line agents (P = 0.02).

Conclusions

This study showed that severe atrophy of the terminal ileum predicts severe clinical GVHD that is likely to be refractory to steroid treatment. Thus, the severity of terminal ileum atrophy may serve as a tool in predicting clinically severe GVHD.

Trial registration

Trial Registration Number UMIN 000022805, Registration date July 1, 2016.

The Perils of Multiplex Gastrointestinal Pathogen Panels: Pseudo-outbreaks of Salmonellae and Entamoeba histolytica in Immunocompromised Hosts

Two distinct clusters of gastroenteritis due to Salmonellae and Entamoeba histolytica (EH) were identified using a multiplex gastrointestinal pathogen panel (GPP) at a tertiary-care cancer center. Despite temporo-spatial overlap, our investigation did not corroborate transmission or true infection. In clinical practice, GPPs may render false-positive results.Infect Control Hosp Epidemiol 2018;867-870.

Use of the National Institutes of Health Consensus Guidelines Improves the Diagnostic Sensitivity of Gastrointestinal Graft-Versus-Host Disease

CONTEXT

- Graft-versus-host disease of the gastrointestinal tract is a common complication of hematopoietic stem cell transplant associated with significant morbidity and mortality. Accurate diagnosis can be difficult and is a truly clinicopathologic endeavor.

OBJECTIVES

- To assess the diagnostic sensitivity of gastrointestinal graft-versus-host disease using the 2015 National Institutes of Health (NIH) histology consensus guidelines and to analyze histologic findings that support the guidelines.

DESIGN

- Patients with allogeneic hematopoietic stem cell transplants were identified via a retrospective search of our electronic medical records from January 1, 2005, to January 1, 2011. Endoscopies with available histology were reviewed by 2 pathologists using the 2015 NIH guidelines. The clinical diagnosis was used as the gold standard. A nontransplant set of endoscopic biopsies was used as a control.

RESULTS

- Of the 250 total endoscopies, 217 (87%) had a clinical diagnosis of gastrointestinal graft-versus-host disease. Use of the NIH consensus guidelines showed a sensitivity of 86% and a specificity of 65%. Thirty-seven of 58 (64%) cases with an initial false-negative histopathologic diagnosis were diagnosed as graft-versus-host disease on our review.

CONCLUSIONS

- Use of the NIH histology consensus guidelines results in a high sensitivity and specificity, thereby decreasing false-negatives. Additionally, use of the NIH guidelines aids in creating uniformity and diagnostic clarity. Correlation with clinical and laboratory findings is critical in evaluating the differential diagnosis and to avoid false-positives. As expected, increased apoptosis with decreased inflammation was associated with a pathologic diagnosis of graft-versus-host disease and supports the NIH guidelines.

Rotavirus Infection in Pediatric Allogeneic Hematopoietic Cell Transplant Recipients: Clinical Course and Experience Using Nitazoxanide and Enterally Administered Immunoglobulins

BACKGROUND

Rotaviruses may produce prolonged and severe disease in allogeneic hematopoietic cell transplant (HCT) recipients. Nitazoxanide and enterally administered human immunoglobulins are potential therapeutic options. This retrospective study describes the clinical course of rotavirus infection in pediatric allogeneic HCT recipients and a single-center experience with nitazoxanide and oral immunoglobulins as potential treatment options.

METHODS

We identified 36 patients who had positive stool rotavirus antigen assays after allogeneic HCT from May 30, 2012, to July 31, 2015. Clinical, microbiologic and treatment data were collected and analyzed using descriptive statistics.

RESULTS

Forty-nine discrete episodes of rotavirus infection were identified among these 36 patients for a cumulative incidence of 19.7%. For these 49 episodes, the median day to infection after HCT was day 82, and the median duration of diarrhea was 17.5 days (range 4-122). Nitazoxanide and enteral immunoglobulins were prescribed for 41 episodes. The median duration of clinical symptoms after initiation of nitazoxanide was 11 days (range 2-85), 23 days (range 10-107) after enteral immunoglobulins and 26 days (range 6-90) after a combination of nitazoxanide and enteral immunoglobulins (P = 0.1). No adverse effects of either treatment were documented, but efficacy could not be assessed in this patient population.

CONCLUSIONS

In pediatric HCT recipients, the clinical illness produced by rotaviruses is prolonged compared with otherwise healthy children. Nitazoxanide appears safe, but its efficacy for this indication requires further study.

Thrombotic microangiopathy with concomitant GI aGVHD after allogeneic hematopoietic stem cell transplantation: Risk factors and outcome

OBJECTIVES

To explore the possible risk factors for the occurrence and mortality of thrombotic microangiopathy (TMA) with concomitant acute graft-vs-host disease (aGVHD) and to investigate outcomes and treatments of this disorder after allo-HSCT.

METHODS

Fifty cases diagnosed with TMA with concomitant aGVHD and 150 controls were identified from a cohort composed of 3992 patients who underwent allo-HSCT from 2008 to 2016.

RESULTS

Grade III-IV aGVHD (P = .000), acute kidney injury (AKI) (P = .033), and hypertension (P = .028) were significant independent risk factors associated with the occurrence of TMA with concomitant aGVHD. A haptoglobin level below normal (P = .013), a maximum volume of diarrhea >2500 mL/d (P = .015), and bloody diarrhea (P = .049) were significant markers for death in both univariate and multivariate analyses. Patients diagnosed with TMA with concomitant aGVHD had a lower overall survival (OS), a higher non-relapse mortality (NRM), but a lower risk of relapse.

CONCLUSIONS

Thrombotic microangiopathy with concomitant aGVHD is a significant complication after allo-HSCT, with a worse outcome, including significantly lower OS and higher NRM. There are specific risk factors associated with occurrence and mortality of this complication.

Acute graft-versus-host disease of the gut: considerations for the gastroenterologist

Haematopoietic stem cell transplantation (HSCT) is central to the management of many haematological disorders. A frequent complication of HSCT is acute graft-versus-host disease (GVHD), a condition in which immune cells from the donor attack healthy recipient tissues. The gastrointestinal system is among the most common sites affected by acute GVHD, and severe manifestations of acute GVHD of the gut portends a poor prognosis in patients after HSCT. Acute GVHD of the gastrointestinal tract presents both diagnostic and therapeutic challenges. Although the clinical manifestations are nonspecific and overlap with those of infection and drug toxicity, diagnosis is ultimately based on clinical criteria. As reliable serum biomarkers have not yet been validated outside of clinical trials, endoscopic and histopathological evaluation continue to be utilized in diagnosis. Once a diagnosis of gastrointestinal acute GVHD is established, therapy with systemic corticosteroids is typically initiated, and non-responders can be treated with a wide range of second-line therapies. In addition to treating the underlying disease, the management of complications including profuse diarrhoea, severe malnutrition and gastrointestinal bleeding is paramount. In this Review, we discuss strategies for the diagnosis and management of acute GVHD of the gastrointestinal tract as they pertain to the practising gastroenterologist.

Loperamide, an antidiarrheal agent, induces apoptosis and DNA damage in leukemia cells

Loperamide, an antidiarrheal agent, is frequently used to treat patients with leukemia with symptoms of diarrhea during treatment. However, the effect of loperamide on leukemia cells is unknown. The MTT assay was used to explore the cytotoxic effect of loperamide on leukemia cells. Morphological analysis and flow cytometry were performed to determine the level of apoptosis in leukemia cells following loperamide treatment. Western blotting was conducted to test the activation of the apoptotic pathway. The comet assay was used to determine the DNA damage induced by loperamide. Loperamide potently inhibited the proliferation of leukemia cell lines and primary leukemia cells from 9 patients with acute myeloid leukemia (AML) and 6 patients with acute lymphocytic leukemia (ALL) in a dose-dependent manner. Loperamide increased the expression of cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase, decreased the expression of myeloid cell lekeumia-1 and induced the apoptosis of leukemia cells. In addition, treatment with 20 µM loperamide increased the expression level of the protein rH2ax and promoted the formation of long DNA comet tails, thus triggering DNA damage in leukemia cells. Finally, DNA damage was confirmed by the activation of the ataxia telangiectasia mutated serine/threonine kinase (ATM)-checkpoint kinase 2 (Chk2) signaling pathway. The phosphorylation level of ATM (Ser1981) and Chk2 (Thr68) was activated and upregulated following DNA damage triggered by loperamide. Loperamide was demonstrated to perform an inhibitory role in the growth of leukemia cell lines and primary leukemia cells. Of note, apoptosis and DNA damage were induced following loperamide treatment in leukemia cell lines and primary leukemia cells.

Safety and Role of Gastrointestinal Endoscopy in the Management of Gastrointestinal Acute GVHD in Children After Hematopoietic Stem Cell Transplantation

Gastrointestinal (GI) endoscopy and biopsy is a common procedure to confirm the diagnosis of acute graft-versus-host disease (aGVHD) in children after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Its safety and benefits in aGVHD management is unclear. We aimed to review the safety and benefits of GI endoscopy and biopsy for GI-aGVHD management. From January 2000 to December 2009, 450 Children received allo-HSCT at SickKids. Seventy-nine (17.5%) patients underwent GI endoscopy and biopsy for suspicion of GI-aGVHD. GI-aGVHD grading was I (n=5), II (n=39), III (n=23), and IV (n=12). GI biopsy confirmed aGVHD in 49 (62%) patients and results were negative in 30 (38%). Thirty-two (40%) patients started treatment based on clinical criteria before procedure. Twenty-four out of 79 patients had a change in therapy because of biopsy results. Treatment change was significantly more common in patients who had a positive biopsy results compared with those with negative results (24/49 vs. 4/30, P=0.02). Comparing patients who started therapy before the biopsy results (n=32) and the remaining patients (n=47) who were not started on therapy, the biopsy results had more impact in altering/starting therapy in these patients (24/47 vs. 0/32, P<0.00001). For the 32 patients who started therapy before the procedure, the biopsy confirmed aGVHD diagnosis in 20 of them (63%). Only 1 patient (1.25%) had duodenal hematoma and needed prolong GI rest and ultimately recovered. GI endoscopy and biopsy was safe and useful in guiding therapy for GI-aGVHD.

Selected Topics in Anaerobic Bacteriology

Alteration in the host microbiome at skin and mucosal surfaces plays a role in the function of the immune system, and may predispose immunocompromised patients to infection. Because obligate anaerobes are the predominant type of bacteria present in humans at skin and mucosal surfaces, immunocompromised patients are at increased risk for serious invasive infection due to anaerobes. Laboratory approaches to the diagnosis of anaerobe infections that occur due to pyogenic, polymicrobial, or toxin-producing organisms are described. The clinical interpretation and limitations of anaerobe recovery from specimens, anaerobe-identification procedures, and antibiotic-susceptibility testing are outlined. Bacteriotherapy following analysis of disruption of the host microbiome has been effective for treatment of refractory or recurrent Clostridium difficile infection, and may become feasible for other conditions in the future.

Sensitivities of Biopsy Sites in the Endoscopic Evaluation of Graft-Versus-Host Disease: Retrospective Review from a Tertiary Center

BACKGROUND

Graft-versus-host disease (GVHD) is a complication of hematopoietic stem cell transplantation that frequently affects the gastrointestinal (GI) tract. The best biopsy sites to establish the diagnosis have not been clearly established.

AIMS

To determine the best sites for obtaining biopsies in evaluating GI GVHD.

METHODS

All cases of biopsy-proven GI GVHD (GVHD+) were isolated from a pathology database over a 2-year period at a single tertiary center (n = 46). Demographic, clinical, and endoscopic data were extracted. For comparison, 46 consecutive GVHD-negative cases (GVHD-) were obtained. Sensitivities in diagnosing GVHD in the upper and lower GI tract were calculated.

RESULTS

In the GVHD- group, they were commonly investigated with an esophagogastroduodenoscopy (EGD) (60 vs. 22 % in the GVHD+ group, p < 0.01), while a colonoscopy (CLN) was commonly performed in the GVHD+ group (33 vs. 12 %, p = 0.02). Among the GVHD + patients, for EGDs, the sensitivity was highest for duodenal biopsies at 89 %. For flexible sigmoidoscopies (FSs) and CLNs, the sensitivities among all sites were similar (85 % agreement, kappa 0.58, p = 0.01). There were no cases in which GVHD was diagnosed in the right side of the colon without a positive biopsy in the left side of the colon.

CONCLUSIONS

In this cohort of GI GVHD patients, duodenum biopsies produced the highest yield in diagnosing GVHD when compared to other sites of the upper GI tract. Sensitivities were similar among all sites on lower endoscopies, suggesting that a FS is sufficient for diagnosing GVHD in suspected patients with diarrhea.

The role of octreotide in symptom management in oncology and palliative care

Objective. To provide an overview of the role of octreotide for managing symptoms in oncology and palliative care.

Data Sources. A search of MEDLINE and IDIS databases from 1985 to 1999 and CANCERLIT from 1993 to 1999 was conducted using the terms octreotide, cancer and palliative care. The reference lists from selected articles were also reviewed. Clinical trial databases on the Internet were searched. Oncology and palliative care textbooks were also used to obtain additional references.

Data Extraction. The retrieved literature was reviewed to discuss the pharmacology, pharmacokinetics, adverse effects, indications and principally, the clinical use of octreotide for controlling a number of symptoms encountered in the oncology and palliative care population.

Data Synthesis. The unique inhibitory activity of octreotide lends itself to many possible indications, including diarrhoea from a number of causes, bowel obstruction, nausea and vomiting, bleeding, death rattle, gastrointestinal fistulae, pain and hypercalcaemia. However, convincing pieces of evidence from large prospective clinical trials are required to realise its full potential in oncology and palliative care. Completed studies and clinical experience suggest that octreotide has a role in the treatment of a number of difficult-to-manage conditions, particularly bowel obstruction and diarrhoea due to disease or treatment-related causes. Proposed benefits of octreotide must be weighed against the possible adverse effects and cost effectiveness of treatment.

Clinical approach to diarrheal disorders in allogeneic hematopoietic stem cell transplant recipients

Diarrhea is a common complication of allogeneic hematopoietic stem cell transplant (HSCT), with an average incidence of approximately 40%-50%. A wide variety of etiologies can contribute to diarrhea in HSCT patients, including medication-induced mucosal inflammation, infections, graft-vs-host disease and cord colitis syndrome in umbilical cord blood transplant. Clinical manifestations can vary from isolated diarrheal episodes, to other organ involvement including pneumonia or myocarditis, and rarely multiorgan failure. The approach for diagnosis of diarrheal disorders in HSCT patients depends on the most likely cause. Given the risk of life-threatening conditions, the development of clinically significant diarrhea requires prompt evaluation, supportive care and specific therapy, as indicated. Serious metabolic and nutritional disturbances can happen in HSCT patients, and may even lead to mortality. In this review, we aim to provide a practical approach to diagnosis and management of diarrhea in the post-transplant period.

How I treat acute graft-versus-host disease of the gastrointestinal tract and the liver

Treatment of acute graft-versus-host disease (GVHD) has evolved from a one-size-fits-all approach to a more nuanced strategy based on predicted outcomes. Lower and time-limited doses of immune suppression for patients predicted to have low-risk GVHD are safe and effective. In more severe GVHD, prolonged exposure to immunosuppressive therapies, failure to achieve tolerance, and inadequate clinical responses are the proximate causes of GVHD-related deaths. This article presents acute GVHD-related scenarios representing, respectively, certainty of diagnosis, multiple causes of symptoms, jaundice, an initial therapy algorithm, secondary therapy, and defining futility of treatment.

Evaluating risk factors for Clostridium difficile infection in adult and pediatric hematopoietic cell transplant recipients

Background

Although hematopoietic cell transplant (HCT) recipients are routinely exposed to classic risk factors for Clostridium difficile infection (CDI), few studies have assessed CDI risk in these high-risk patients, and data are especially lacking for pediatric HCT recipients. We aimed to determine incidence and risk factors for CDI in adult and pediatric allogeneic HCT recipients.

Methods

CDI was defined as having diarrhea that tested positive for C. difficile via PCR, cytotoxin assay, or dual enzyme immunoassays. We included all patients who received an allogeneic HCT from 2008 to 2012 at the Fred Hutchinson Cancer Research Center; those <1 year old or with CDI within 8 weeks pre-HCT were excluded. Patients were categorized by transplanting hospital (“adult” or “pediatric”) and followed for 100 days post-HCT.

Results

Of 1182 HCT recipients, CDI was diagnosed in 17 % (33/192) of pediatric recipients for an incidence of 20 per 10,000 patient-days, and 11 % (107/990) of adult recipients for an incidence of 12 per 10,000. Pediatric recipients were diagnosed a median of 51 days (interquartile range [IQR]: 5, 72) after HCT and adults at 16 days (IQR = 5, 49). Compared with calendar year 2008, pediatric recipients transplanted in 2012 were at increased risk for CDI (hazard ratio [HR] = 3.99, p =.02). Myeloablative conditioning increased CDI risk in adult recipients (HR = 1.81, p =.005).

Conclusions

Pediatric and adult allogeneic recipients are at high risk of CDI post-HCT, particularly adult recipients of myeloablative conditioning. Differences in CDI incidence between children and adults may have resulted from exposure differences related to age; therefore, separately evaluating these groups should be considered in future CDI studies.

Colonoscopy and Sigmoidoscopy are Equally Effective for the Diagnosis of Colonic Acute Graft-versus-Host Disease in Patients with Diarrhea after Allogeneic Stem Cell Transplantation: A Prospective Controlled Trial

Colonic acute graft-versus-host disease (aGVHD) affects approximately 10% of patients who have undergone allogeneic stem cell transplantation (allo-SCT). Diarrhea is a major clinical sign but also a common post-transplantation symptom in these patients. Comprehensive histopathologic examination of the colon is therefore regarded as crucial to establish a diagnosis, but the colonic segment that should be targeted for a diagnostic biopsy remains a topic of debate. The primary objective of this study was to compare prospectively colonoscopy with sigmoidoscopy regarding their capabilities to provide a histopathologically proven diagnosis of colonic aGVHD. Thirty-seven allo-SCT patients with diarrhea all underwent a colonoscopy. All biopsies collected from the descending colon were regarded as also attainable by sigmoidoscopy, whereas biopsies collected in regions further up the colon (from the transverse and ascending colon) were regarded as acquirable exclusively by colonoscopy. Biopsies attainable by colonoscopy and sigmoidoscopy were positive for GVHD in 25 (68%) and 24 (65%) patients, respectively (95% confidence interval for difference of proportions, -.185 to .245; P = .978; z = .0271 by the z-test). Sigmoidoscopy is as effective as colonoscopy in establishing a diagnosis of colonic aGVHD in patients who have diarrhea after allo-SCT.

Noroviruses as a Cause of Diarrhea in Immunocompromised Pediatric Hematopoietic Stem Cell and Solid Organ Transplant Recipients

Case reports describe significant norovirus gastroenteritis morbidity in immunocompromised patients. We evaluated norovirus pathogenesis in prospectively enrolled solid organ (SOT) and hematopoietic stem cell transplant (HSCT) patients with diarrhea who presented to Texas Children's Hospital and submitted stool for enteric testing. Noroviruses were detected by real-time reverse transcription polymerase chain reaction. Clinical outcomes of norovirus diarrhea and non-norovirus diarrhea patients, matched by transplanted organ type, were compared. Norovirus infection was identified in 25 (22%) of 116 patients, more frequently than other enteropathogens. Fifty percent of norovirus patients experienced diarrhea lasting ≥14 days, with median duration of 12.5 days (range 1-324 days); 29% developed diarrhea recurrence. Fifty-five percent of norovirus patients were hospitalized for diarrhea, with 27% requiring intensive care unit (ICU) admission. One HSCT recipient developed pneumatosis intestinalis. Three HSCT patients expired ≤6 months of norovirus diarrhea onset. Compared to non-norovirus diarrhea patients, norovirus patients experienced significantly more frequent ICU admission (27% vs. 0%, p = 0.02), greater serum creatinine rise (median 0.3 vs. 0.2 mg/dL, p = 0.01), and more weight loss (median 1.6 vs. 0.6 kg, p < 0.01). Noroviruses are an important cause of diarrhea in pediatric transplant patients and are associated with significant clinical complications.

Acute graft-versus-host disease is more prevalent and severe in the lower than the upper gastrointestinal tract

It is unclear whether acute gastrointestinal (GI) graft-versus-host disease (GVHD) affects all segments of the GI tract equally. Up to 45% patients reported showed discrepancy in involvement between upper GI (UGI) and lower GI (LGI) tract. We compared the prevalence and the severity of acute GVHD in UGI and LGI tract on histologic examination. A cohort of 110 cases of simultaneous UGI and LGI biopsies from 105 allogeneic hematopoietic stem cell transplantation recipients with clinically confirmed GI GVHD were reviewed retrospectively. The χ(2) test and 1-way analysis of variance test were used for statistical analysis. Most (75%) of the cases had GVHD involvement in both UGI and LGI tracts, whereas UGI-only GVHD was found in 6% and LGI-only GVHD in 19%. GVHD prevalence was the lowest in stomach (61%) and significantly increased toward duodenum/jejunum (81%; P = .0019). The LGI tract showed similar GVHD prevalence (P = .3648); the highest was in the sigmoid colon (97%). The histologic grade was lowest in the stomach (mean ± SD, 1.6 ± 0.8) and was similar across all UGI segments (P = .0883). The histologic grade in LGI significantly increased (P = .0265) from the terminal ileum (2.0 ± 1.3) to the rectum (2.9 ± 1.0). Overall, both the prevalence and the histologic grade of GVHD in LGI were significantly higher than those of UGI (P < .0001 for both). Our results show that acute GVHD had a higher prevalence and was more severe in the LGI than in UGI tract. A small subset of patients had only UGI involvement.

Rotavirus in organ transplantation: drug-virus-host interactions

Although rotavirus is usually recognized as the most common etiology of diarrhea in young children, it can in fact cause severe diseases in organ transplantation recipients irrespective of pediatric or adult patients. This comprehensive literature analysis revealed 200 cases of rotavirus infection with 8 related deaths in the setting of organ transplantation been recorded. Based on published cohort studies, an average incidence of 3% (187 infections out of 6176 organ recipients) was estimated. Rotavirus infection often causes severe gastroenteritis complications and occasionally contributes to acute cellular rejection in these patients. Immunosuppressive agents, universally used after organ transplantation to prevent organ rejection, conceivably play an important role in such a severe pathogenesis. Interestingly, rotavirus can in turn affect the absorption and metabolism of particular immunosuppressive medications via several distinct mechanisms. Even though rotaviral enteritis is self-limiting in general, infected transplantation patients are usually treated with intensive care, rehydration and replacement of nutrition, as well as applying preventive strategies. This article aims to properly assess the clinical impact of rotavirus infection in the setting of organ transplantation and to disseminate the interactions among the virus, host and immunosuppressive medications.

Gastrointestinal pathology in transplant patients

The assessment of gastrointestinal (GI) specimens from transplant patients is complicated by the wide range of potentially rare pathologies that may be found in this clinical setting. Acute GI graft-versus-host disease (GvHD) is characterized by epithelial cell apoptosis, although there is increasing recognition that acute and/or chronic inflammation may also be present. By contrast, thus far there are no histological features known to be specific to chronic GI GvHD. Mycophenolate mofetil colitis may mimic both GvHD and inflammatory bowel disease, whereas both cytomegalovirus (CMV) and adenovirus infections can cause gland apoptosis. Post-transplant lymphoproliferative disorder should be considered if a Crohn's-like histological picture is seen, and granulomas in biopsies from umbilical cord blood recipients should raise a suspicion of cord colitis syndrome. Finally, the GI tract may be involved directly or indirectly by the disease that originally required haematopoietic stem cell or liver transplantation.

Clinicopathological features of patients with acute graft-versus-host disease of the upper digestive tract

BACKGROUND AND AIMS

Acute graft-versus-host disease (GVHD) occurring within 100 days post-transplant is one of critical factors influencing prognosis in transplant recipients. Among cases of GVHD of the gastrointestinal (GI) tract, GVHD rarely affects the upper GI. In this study, we retrospectively examined the frequency of upper GI GVHD and diagnostic accuracy.

PATIENTS AND METHODS

From among 868 patients who underwent allogeneic hematopoietic stem cell transplantation at our hospital between January 2005 and June 2012, 115 of whom underwent biopsy for upper GI symptoms. The endoscopic findings and histologic diagnosis from these 115 patients were retrospectively analyzed.

RESULTS

GVHD was histologically diagnosed in 85 patients overall (9.8% of all 868 transplant recipients). Although gastric mucosal exfoliation was not commonly observed, this endoscopic finding when used as a diagnostic predictor had both a specificity and positive predictive value (PPV) of 100%. When using redness, luster, and mucosal change as predictors, specificity and PPV were relatively high, suggesting that these gastric endoscopic findings are useful in the diagnosis of upper GI GVHD. Among the duodenal endoscopic findings, erosion as a diagnostic predictor had both a high specificity and PPV. The biopsy results often lead to a diagnosis of GVHD even in cases judged to be endoscopically normal.

CONCLUSIONS

Among the gastric endoscopic findings, mucosal exfoliation, although rare, and redness, luster, and mucosal change are likely to be useful diagnostic predictors of upper GI GVHD. GVHD was frequently diagnosed in patients with endoscopically normal duodenum, suggesting that biopsies are important for definitive diagnosis.

Human astroviruses

Human astroviruses (HAtVs) are positive-sense single-stranded RNA viruses that were discovered in 1975. Astroviruses infecting other species, particularly mammalian and avian, were identified and classified into the genera Mamastrovirus and Avastrovirus. Through next-generation sequencing, many new astroviruses infecting different species, including humans, have been described, and the Astroviridae family shows a high diversity and zoonotic potential. Three divergent groups of HAstVs are recognized: the classic (MAstV 1), HAstV-MLB (MAstV 6), and HAstV-VA/HMO (MAstV 8 and MAstV 9) groups. Classic HAstVs contain 8 serotypes and account for 2 to 9% of all acute nonbacterial gastroenteritis in children worldwide. Infections are usually self-limiting but can also spread systemically and cause severe infections in immunocompromised patients. The other groups have also been identified in children with gastroenteritis, but extraintestinal pathologies have been suggested for them as well. Classic HAstVs may be grown in cells, allowing the study of their cell cycle, which is similar to that of caliciviruses. The continuous emergence of new astroviruses with a potential zoonotic transmission highlights the need to gain insights on their biology in order to prevent future health threats. This review focuses on the basic virology, pathogenesis, host response, epidemiology, diagnostic assays, and prevention strategies for HAstVs.

Recipient pretransplant inosine monophosphate dehydrogenase activity in nonmyeloablative hematopoietic cell transplantation

Mycophenolic acid, the active metabolite of mycophenolate mofetil (MMF), inhibits inosine monophosphate dehydrogenase (IMPDH) activity. IMPDH is the rate-limiting enzyme involved in de novo synthesis of guanosine nucleotides and catalyzes the oxidation of inosine 5'-monophosphate to xanthosine 5'-monophosphate (XMP). We developed a highly sensitive liquid chromatography-mass spectrometry method to quantitate XMP concentrations in peripheral blood mononuclear cells (PMNCs) isolated from the recipient pretransplant and used this method to determine IMPDH activity in 86 nonmyeloablative allogeneic hematopoietic cell transplantation (HCT) patients. The incubation procedure and analytical method yielded acceptable within-sample and within-individual variability. Considerable between-individual variability was observed (12.2-fold). Low recipient pretransplant IMPDH activity was associated with increased day +28 donor T cell chimerism, more acute graft-versus-host disease (GVHD), lower neutrophil nadirs, and more cytomegalovirus reactivation but not with chronic GVHD, relapse, nonrelapse mortality, or overall mortality. We conclude that quantitation of the recipient's pretransplant IMPDH activity in PMNC lysate could provide a useful biomarker to evaluate a recipient's sensitivity to MMF. Further trials should be conducted to confirm our findings and to optimize postgrafting immunosuppression in nonmyeloablative HCT recipients.