Graft-vs.-host reactions: mechanisms and contemporary theories

A graft-vs.-host (GvH) reaction can be initiated by injection of immunocompetent lymphocytes into a histoincompatible host that is unable to reject these cells. The reaction is characterized by splenomegaly, hepatomegaly, lymph node atrophy, body weight loss, dermatitis, and diarrhea, often leading to mortality. The onset and severity of the GvH reaction are determined by differences in histocompatibility antigens between the donor and the acceptor, and by the number and nature of the transplanted allogeneic cells. Many different in vivo and in vitro systems have been devised for experimental studies of the GvH reaction. In several of these models, however, different parameters are measured. Furthermore, the conclusions drawn from these investigations sometimes contradict each other. This paper reviews the experimental data, and discusses the mechanisms underlying the GvH reaction.     

In vitro and in vivo activity of murine lymphokine-activated killer cells after cryopreservation

The in vitro and in vivo effects of cryopreservation on the cytotoxic activity of murine lymphokine-activated killer (LAK) cells were studied. LAK cells were generated by incubation of spleen lymphocytes of BALB/c mice for 3 days with recombinant interleukin-2 (rIL-2) and subsequent cryopreservation. Cytotoxicity was determined in a 51Cr release assay. After thawing, cytotoxic activity was reduced (40.4% 51Cr release at an effector:target cell ratio of 40:1 as compared to 68.5% 51Cr release before freezing) and could be restored to precryopreserved levels by reincubation with rIL-2 for 2 days after thawing (78.8% 51Cr release). These cells were then tested in BALB/c mice injected with RAW 112 cells, a pre-B-cell lymphoma line. The results demonstrate that the survival rate of mice injected with cryopreserved and restimulated LAK cells (50% survival greater than 180 days after injection) did not differ significantly from that of mice injected with fresh unfrozen LAK cells (60% survival greater than 120 days, 50% survival greater than 180 days). Cryopreserved LAK cells have potential use in adoptive immunotherapy.     

Dietary Assessment of Individuals with Chronic Kidney Disease

Examining the quality and quantity of food intake by appropriate methods is critical in the management of patients with chronic kidney disease (CKD). The four commonly used dietary assessment methods in CKD patients include short‐term dietary recalls, several days of food records with or without dietary interviews, urea kinetic based estimates such as protein nitrogen appearance calculation, and food histories including food screeners and food frequency questionnaires (FFQ). There are a number of strengths and limitations of these dietary assessment methods. Accordingly, none of the four methods is suitable in and of itself to give sufficiently accurate dietary information for all purposes. Food frequency questionnaires, which is the preferred method for epidemiological studies, should be used for dietary comparisons of patients within a given population rather than individual assessment. Food histories including FFQ and dietary recalls may underestimate important nutrients, especially in CKD patients. Given the large and increasing number of dialysis patients and work responsibilities of renal dietitians, routine analysis of dietary records and recalls is becoming less feasible. Ongoing and future studies will ascertain additional strengths and limitations of dietary assessment methods in CKD populations including the assessment of food intake during an actual hemodialysis treatment.     

Prevalence of upper and lower gastrointestinal tract findings in liver transplant candidates undergoing screening endoscopic evaluation

OBJECTIVE: The incidence of esophageal and gastric varices and portal hypertensive gastropathy (PHG) has been well studied in cirrhotic patients. Because little is known of the prevalence of other upper and lower gastrointestinal tract pathology in pre-liver transplant candidates, we retrospectively studied the prevalence of and factors associated with these findings. METHODS: One hundred and twenty pre-liver transplant candidates underwent esophagogastroduodenoscopy to evaluate for varices, and 71 of them also underwent flexible sigmoidoscopy to screen for colorectal carcinoma. The association of upper and lower GI tract pathology with Child-Pugh Class, etiology of cirrhosis, and signs of portal hypertension, including presence and size of esophageal varices, presence of gastric varices, PHG, ascites, and splenomegaly, was analyzed using univariate and multivariate analysis. RESULTS: Etiology of cirrhosis among 87 men and 33 women (mean age, 52 yr) included 25% hepatitis C, 27% hepatitis C/alcohol, 15% alcohol, 10% primary sclerosing cholangitis/primary biliary cirrhosis, 9% cryptogenic, 8% metabolic, and 6% hepatitis B. Prevalence of Child-Pugh Classes A, B, and C were 34%, 49%, and 17%, respectively; 73% of patients had esophageal varices (23% were large), 62% PHG (23% were severe), and 16% gastric varices. Excluding varices and PHG, endoscopic findings in the upper GI tract (n = 120) included: 13% esophagitis/ulcers, 7.5% gastritis, 8% duodenitis, 2% Barrett's esophagus, 3% duodenal ulcers, and 2% gastric ulcers. Findings in the lower gastrointestinal tract (n = 71) included 21% adenomatous polyps, 21% internal hemorrhoids, 15% diverticulosis, 7% rectal varices, 3% colopathy, and 3% vascular ectasias. Univariate analysis revealed that there was a significant association between rectal varices and severe PHG (p < 0.05). This association was not maintained when multivariate analysis was performed. CONCLUSIONS: Among all the findings, only rectal varices and colopathy were of higher prevalence in the pre-liver transplant population than that reported for the general population. No significant associations were found between these gastrointestinal tract lesions and patient characteristics.     

Success of MRSA Eradication in Hospital Routine: Depends on Compliance

Abstract Background: To prevent transmission of MRSA, eradication by antiseptic washings and nasal ointment is recommended. There are few studies, which investigated the success of eradication of MRSA carriage during everyday clinical working conditions and results are controversial. We wanted to assess the effectiveness of MRSA eradication procedures – especially octenidine whole body washings and mupirocin nasal ointment – under conditions of everyday life. Patients and Methods: We retrospectively analyzed the files of all patients who were admitted to the medical department of a tertiary care hospital between 1999 and 2004 and who were infected or colonized by MRSA. According to hospital’s standards of care patients should have been washed with octenidine and should have got mupirocin nasal ointment only in case of nasal carriage. Patients were regarded as MRSA-eradicated when swabs taken on three consecutive days, earliest, three days after discontinuation of antiseptic and antiinfective procedures were without proof of MRSA. Results: Only 6% of patients were eradicated. MRSA could be cultured from swabs taken on dismissal of 60% of patients. Fifteen percent of patients had only one or two negative series of swabs. In 19% of patients success of eradication remained unknown. Besides we found that under every day clinical working conditions compliance with several tasks of the eradication protocol was insufficient. Conclusion: Under every day clinical working conditions MRSA eradication is successful only in few patients. Whole body washings should be tested in detailed studies before they should become a recommendation for eradication of MRSA.