CAGS AND ACS EVIDENCE BASED REVIEWS IN SURGERY. 49: Is a diverting loop ileostomy and colonic lavage an alternative to colectomy for the treatment of severe Clostridium difficile–associated disease?

Objective: To determine whether a colon-sparing diverting ileostomy with colonic lavage reduces mortality in patients with severe Clostridium difficile–associated disease (CDAD) when compared with colectomy. Design: Retrospective cohort study. Setting & patients: Forty-two patients with diagnosed severe, complicated CDAD who were treated at the University of Pittsburgh Medical Center or VA Pittsburgh Health Care System between June 2009 and January 2011 with diverting loop ileostomy and colonic lavage (warmed polyethylene glycol 3350/electrolyte solution via the ileostomy and postoperative antegrade instillation of vancomycin flushes via the ileostomy). Patients were compared with a historical control group of 42 patients who had a colectomy. Main outcome: Resolution of CDAD. Results: There was no significant difference in age, sex, pharmacologic immuno-suppression and Acute Physiology and Chronic Health Evaluation-II (APACHE-II) scores between the current cohort and historical controls. In the ileostomy group, surgery was performed laparoscopically in 35 patients (83%). This treatment strategy resulted in reduced mortality compared with the historical population (19% v. 50%; odds ratio [OR] 0.24, p = 0.006). Preservation of the colon was achieved in 39 of 42 patients (93%). Conclusion: Loop ileostomy and colonic lavage are an alternative to colectomy in the treatment of severe, complicated CDAD, resulting in reduced morbidity and preservation of the colon.     

Anti‐D investigations in individuals expressing weak D Type 1 or weak D Type 2: allo‐ or autoantibodies?

BACKGROUND: Whether anti‐D produced by individuals with a weak D phenotype are allo‐ or autoantibodies remains a matter of debate even though blood transfusion practice is impacted. The aim of our study was to determine the serologic features of anti‐D in individuals expressing the most frequent weak D type in Caucasians that are weak D Type 1 or weak D Type 2, to assess whether anti‐D were allo‐ or autoantibodies. STUDY DESIGN AND METHODS: Serologic D typing and molecular analysis enabled the including of 121 weak D Type 1 individuals and 99 weak D Type 2 individuals in our study. Serologic features of anti‐D included autologous controls, direct antiglobulin test, elution, and titration of anti‐D before and after adsorption of serum on autologous red blood cells (RBCs). RESULTS: Serologic D typing showed a variable reactivity of RBCs expressing weak D Type 1 or weak D Type 2 (4+ to 0). Anti‐D was identified in six weak D Type 1 and six weak D Type 2 individuals, respectively. The serologic data were in favor of autoantibodies. CONCLUSION: A complete anti‐D investigation in individuals with a D variant (weak D or partial D identified by molecular analysis) should be systematically performed before any valid conclusion on the nature of the antibody. Transfusing weak D Type 1 or weak D Type 2 patients with D+ RBC units should be recommended. Weak D Type 1 or weak D Type 2 pregnant women do not need anti‐D immunoprophylaxis.     

Use of OmpU porins for attachment and invasion of Crassostrea gigas immune cells by the oyster pathogen Vibrio splendidus

OmpU porins are increasingly recognized as key determinants of pathogenic host Vibrio interactions. Although mechanisms remain incompletely understood, various species, including the human pathogen Vibrio cholera, require OmpU for host colonization and virulence. We have shown previously that OmpU is essential for virulence in the oyster pathogen Vibrio splendidus LGP32. Here, we showed that V. splendidus LGP32 invades the oyster immune cells, the hemocytes, through subversion of host-cell actin cytoskeleton. In this process, OmpU serves as an adhesin/invasin required for β-integrin recognition and host cell invasion. Furthermore, the major protein of oyster plasma, the extracellular superoxide dismutase Cg-EcSOD, is used as an opsonin mediating the OmpU-promoted phagocytosis through its RGD sequence. Finally, the endocytosed bacteria were found to survive intracellularly, evading the host defense by preventing acidic vacuole formation and limiting reactive oxygen species production. We conclude that (i) V. splendidus is a facultative intracellular pathogen that manipulates host defense mechanisms to enter and survive in host immune cells, and (ii) that OmpU is a major determinant of host cell invasion in Vibrio species, used by V. splendidus LGP32 to attach and invade oyster hemocytes through opsonisation by the oyster plasma Cg-EcSOD.     

Outcomes of Ileal Pouch Excision: an American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) Analysis

Background

This study aimed to define the incidence and risk factors of postoperative morbidity and mortality after pouch excision (PE).

Methods

ACS-NSQIP database was queried for patients who underwent PE between 2005 and 2015. Main outcome measures were 30-day mortality, major morbidity, overall surgical site infections (SSI), reoperation, and length of stay (LOS). Risk factors associated with these outcomes were assessed using multivariate logistic or quantile regression.

Results

Three hundred eighty-one patients underwent PE (mean age 47.7(±15.3) years; 51.7% female). Mean body mass index (BMI) was 24.6(±5.7) kg/m², 55.4% were ASA class 1–2 and 18.4% were immunosuppressed. Mean operative time was 252(±112.7) min, 98% were elective cases, and median LOS was 7(5–11) days. Twenty-eight percent experienced major morbidity, including SSIs (21.5% overall, 9.2% superficial, 3.7% deep, 10.3% organ space), sepsis (9.5%), urinary tract infection (5.8%), and postoperative pneumonia (2.4%). The observed venous thromboembolism rate was low, with 0.5 and 0.8% of patients suffering pulmonary embolism and deep vein thrombosis, respectively; 5.5% required reoperation. Postoperative mortality was 0.8%. On multivariate logistic regression, smoking (OR 3.03 [95% CI 1.56, 5.88]) and operative time (OR 1.003 [95% CI 1.0003, 1.0005) were associated with increased odds of major morbidity. Smoking (OR 3.29 [95% CI 1.65, 6.54]) and operative time (OR 1.002 [95% CI 1.000, 1.004]) were independent risk factors for overall SSI. LOS was significantly increased in patients with major morbidity (3.29 days [95% CI 1.60, 4.99]) and increased operative time (0.013 days [95% CI 0.007, 0.018]).

Conclusions

PE is an operation with significant risk of morbidity. However, mortality was low in the present cohort of patients. Patients who were smokers and had longer operative time had increased risk of overall infectious complications and major morbidity. Furthermore, major morbidity and operative time were associated with increased hospital length of stay following PE.

     

Rituximab therapy for acute humoral rejection after kidney transplantation

A pilot study was performed on eight consecutive renal-transplant (RT) patients presenting with acute humoral rejection (AHR) to assess the efficacy of monoclonal anti-B cell antibodies, such as rituximab (375 mg/m weekly) for 3 to 5 consecutive weeks, in addition to plasma exchange (PE), steroids, mycophenolate mofetil, and tacrolimus. AHR was associated with increased serum creatinine, the appearance of donor-specific alloantibodies (DSA), and the presence of C4d in a transplant biopsy. After a follow-up of 10 months (range 7-23), patient and graft survivals were 100% and 75%, respectively. Renal function improved in six cases in which serum creatinine decreased from 297+/-140 to 156+/-53 micromol/L (P=0.015); graft loss occurred in two cases; and four patients had infectious complications. At last follow-up, DSA had disappeared or decreased in four cases. Rituximab therapy, in addition to PE, might be of benefit for RT patients presenting with AHR.     

Validation of a Rapid Immunochromatographic Assay for Diagnosis of Trypanosoma cruzi Infection among Latin-American Migrants in Geneva,Switzerland

Chagas'' disease is a global public health problem due to the recent exchange of population between Latin America and other regions, including Europe. The recent development of rapid diagnostic tests (RDTs) for Trypanosoma cruzi infection may improve patient access to diagnosis and care worldwide. We evaluated the diagnostic accuracy of the Chagas Stat-Pak RDT in a cohort of undocumented Latin-American migrants living in Geneva, Switzerland. Study participants were enrolled in a primary health care center. The Chagas Stat-Pak test was performed independently on blood and serum samples. A combination of two commercialized enzyme-linked immunosorbent assay (ELISA)-based serological tests was used for comparison (reference standard). A total of 999 adults (median age, 36 years) were included in the study; the majority were women (83%) and originally from Bolivia (47%) or Brazil (25%). A total of 125 participants (12.5%) were diagnosed with T. cruzi infection; with the exception of three individuals, all individuals diagnosed with T. cruzi were originally from Bolivia. The sensitivity and specificity of the Chagas Stat-Pak test on blood samples were 95.2% (95% confidence interval [95% CI], 89.2% to 97.9%) and 99.9% (95% CI, 99.3% to 100%), respectively. When the test was performed on serum samples, the sensitivity was 96% (95% CI, 91% to 98.3%), and the specificity was 99.8% (95% CI, 99.2% to 99.9%). The concordance of test results for blood and serum samples was 99.7%. Both negative and positive predictive values were above 98%. The Chagas Stat-Pak is an accurate diagnostic test for T. cruzi infection among Latin-American migrants living in Europe. The mild deficit in sensitivity should be interpreted in light of its ease of use and capacity to provide immediate results, which allow more people at risk to have access to diagnosis and care both in countries where Chagas'' disease is endemic and in countries where this disease is not endemic.Chagas'' disease is caused by Trypanosoma cruzi, a protozoan parasite naturally transmitted by hematophagous triatomine insects. The parasite can also be transmitted by blood transfusion or organ transplantation, from mother to fetus, sporadically by ingestion of contaminated food or drinks, and rarely by laboratory accident. Vector-borne transmission is restricted to the Americas, where an estimated 8 million people are infected, with the majority undiagnosed and in the chronic stage of the disease (15). However, Chagas'' disease should now be considered a global disease mainly due to important migration movements between Latin America and the United States, Canada, Japan, Australia, and many European countries (19). Physicians working outside Latin America should be aware not only of the chronic cardiac and digestive complications that occur in 20 to 30% of infected patients typically after 10 to 30 years but also of the risk of active local transmission of T. cruzi to newborns (vertical transmission) and to recipients of infected blood or organs.In Europe, many countries are affected by the emergence of Chagas'' disease, Spain being the most affected country with an estimated 36,000 to 122,000 infected people (6, 16). Switzerland has not been spared, with several reported cases of chronic disease with and without cardiopathy, congenital infections, and reactivation following organ transplant over the last few years (7, 9). Many Latin-American immigrants at risk for T. cruzi infection who recently settled down in Switzerland have neither residence permit nor health insurance (undocumented). The majority are women of childbearing age who are employed in the domestic industry (i.e., housecleaning and keeping children). A recent study conducted within this population in Geneva, Switzerland, showed that 130 out of 1,012 (12.8%) persons were infected by T. cruzi, with a very high prevalence found among Bolivians (26.2%) (8).The diagnosis of T. cruzi infection among immigrants living in countries where T. cruzi infection is not endemic, such as Switzerland, is crucial. First, it allows individuals to receive antiparasitic treatment, which is likely to prevent or slow down the progression of chronic organ damage (22). Treating women of childbearing age may also decrease the risk of vertical transmission of T. cruzi during subsequent pregnancies. Second, systematic screening of pregnant women at risk allows for early detection of infection in newborns at the time of delivery or early after delivery, antiparasitic drugs being highly efficacious and well tolerated during the first 3 years of life (1, 9). Third, screening blood and organ donors at risk prevents the transmission of T. cruzi. Last, screening immunosuppressed individuals (e.g., organ transplant recipients) allows for early detection and treatment of disease reactivation.The diagnosis of Chagas'' disease during the chronic phase relies on serological tests, as both parasitological and molecular methods lack sensitivity. As no single assay is considered both sufficiently sensitive and specific, two or more tests based on different antigens or techniques are used in parallel to increase diagnostic accuracy. Recently, rapid diagnostic tests (RDTs), such as the Chagas Stat-Pak (Chembio Diagnostic Systems, Medford, NY), have been developed using recombinant proteins in an immunochromatographic assay. The main advantages of RDTs are (i) devices available for individual use, (ii) rapid processing, (iii) storage at room temperature, (iv) no requirement for laboratory reagents or equipment, (v) no need for specialized laboratory technical skills, and (vi) the possibility of storing the device with the patient''s file (13). The Chagas Stat-Pak assay (on serum) was initially evaluated in multicentric studies conducted in South and Central America, yielding sensitivity and specificity estimates of 98.5 to 100% and 94.8 to 99.9%, respectively (12, 17). Two field evaluations of the Chagas Stat-Pak assay (on finger-pricked blood) in Bolivia showed sensitivity and specificity estimates of 93.4 to 94.7 and 97.3 to 99%, respectively (3, 18). The lower sensitivity estimates observed in the two latter studies could be caused by the use of blood instead of serum. A direct comparison of the Chagas Stat-Pak on blood and serum showed similar results but on a limited number of samples (n = 33) (12). Other factors, such as geographic location, age, and pregnancy, have been shown to influence the performance of the Stat-Pak (3, 20, 21). The Chagas Stat-Pak has never been evaluated in migrants living outside Latin America who carry no risk of chronic reinfections. Therefore, we aimed to evaluate and compare the diagnostic performance of the Chagas Stat-Pak on blood and serum samples from a cohort of Latin-American migrants originally from various countries where Chagas'' disease is endemic and living in Geneva, Switzerland.