Comparison of culture and serology for the diagnosis of cytomegalovirus infection in kidney and liver transplant recipients

This study compared culture, including the shell vial procedure, with serology, including IgM cytomegalovirus (CMV) antibody testing, for the diagnosis of CMV infection in 42 subjects undergoing cadaveric renal or liver transplantation. Of 35 subjects who developed active CMV infection, 31 had positive cultures, while IgM CMV antibodies were detected in 29. Subjects with symptomatic CMV infection were more likely than asymptomatic subjects to have positive cultures of leukocytes (17/18 vs. 9/17, P = .01). In contrast, symptomatic and asymptomatic subjects did not differ in their IgG or IgM CMV antibody test responses. In subjects with symptomatic infection, viral shedding typically began early in the course of infection, often preceding symptoms, while the serologic response usually followed the appearance of symptoms. With the use of the shell vial procedure to facilitate detection of positive cultures, symptomatic CMV infections following kidney or liver transplantation can be recognized earlier and more reliably using viral culture than by serologic testing.     

The resistance of P. acnes--primed interferon gamma-deficient mice to low-dose lipopolysaccharide-induced acute liver injury

Endotoxin has been identified as a principal mediator of sepsis, often with resulting multiple organ failure. Although interferon gamma (IFN-gamma) has a central role in controlling bacterial infection through the activation of macrophages and T lymphocytes, it can also enhance the harmful effects of the inflammatory response. To examine the role of IFN-gamma in lipopolysaccharide (LPS)-induced injury, we administered LPS (20 or 800 microg/mouse) alone or as low-dose LPS (20 microg/mouse) 7 days after heat-killed Propionibacterium acnes (P. acnes) injection into wild-type C57BL/6 (B6) mice or IFN-gamma-deficient (GKO) mice (B6 background). Although low-dose (20 microg) LPS alone had no effect on survival, the administration of 800 microg LPS alone resulted in 100% mortality in both B6 and GKO mice without significant hepatic mononuclear cellular infiltration or differences in elevated plasma tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), and IL-12 levels. In contrast, mortality after low-dose (20 microg) LPS challenge in P. acnes-primed B6 mice was 100%, but 0% in GKO mice. In vivo plasma cytokine (IFN-gamma, TNF-alpha, IL-6, and IL-12) levels and in vitro cytokine production by hepatic mononuclear cells were significantly higher in B6 mice compared with GKO mice. Associated hepatic mononuclear cellular infiltration, multifocal liver necrosis, hepatomegaly, and splenomegaly were found in B6 mice, but not in GKO mice. Finally, the anti-inflammatory NK1.1+CD4+ cell proportion of hepatic infiltrating mononuclear cell numbers 7 days after P. acnes administration was significantly reduced in B6 compared with GKO mice, whereas the proportion of inflammatory NK1.1+CD4- cells was increased. In conclusion, these data suggest that IFN-gamma mediates P. acnes-primed low-dose LPS injury through the hepatic infiltration of mononuclear cells and the subsequent elevation of inflammatory cytokines after LPS challenge, whereas the lethal effects of high-dose LPS alone does not depend on the presence of IFN-gamma.     

Detection of meticillin‐resistant staphylococcus aureus (MRSA) colonization in newborn infants using real‐time polymerase chain reaction (PCR)

Objective: Meticillin‐resistant staphylococcus aureus (MRSA) colonization on neonatal units is a common and important clinical problem. Effectiveness of polymerase chain reaction (PCR) for detecting MRSA nasal colonization of infants was evaluated and compared to culture‐based methods. The effect of skin decolonization in affected infants was studied. Methods: Paired nasal swabs were collected from infants in our neonatal unit over a 12‐month period (September 2007–2008). Colonization with MRSA was determined with a commercially available PCR method and compared to culture. Results: A total of 696 paired nasal swabs were taken. Three infants were colonized at the beginning and were included. There were positive PCRs in 12 infants. Five infants cultured MRSA from a nasal swab at the same time. No infants were culture‐positive when PCR was negative (sensitivity 100%, specificity 99% compared to culture). PCR results were available within 24 h. Five infants were PCR+ and isolated meticillin‐sensitive Staphylococcus aureus. This organism gave a false‐positive PCR result. Two infants transferred in on broad‐spectrum antibiotics were PCR+ and negative by culture. Decolonization led to negative nasal PCR and culture in 4/5 infants to discharge. Conclusions: PCR methods are sensitive and specific for detection of MRSA colonization in newborn infants of all gestations with results 1–2 days before culture.     

Regulatory cells develop after the spontaneous acceptance of rat liver allografts

BACKGROUND: After donor-specific transfusion, tolerance to heart transplants is serially passed to naive rats by the adoptive transfer of long-term survivor (LTS)-tolerant splenocytes (SC). We examined whether regulatory cells similarly develop after the spontaneously accepted Lewis (LEW) to Dark Agouti (DA) liver transplants. METHODS: SC from a LTS DA rat with a LEW liver were adoptively transferred to a naive DA 1 day before transplantation of an irradiated (1000 rad) LEW liver. RESULTS: Untreated LEW to DA liver allografts were uniformly accepted; whereas all irradiated LEW liver grafts were rejected. In contrast, when 1.5 x 10 8 DA LTS SC were transferred to a naive DA recipient, all irradiated LEW liver grafts were accepted. When decreased to 1.0 x 10 8 LTS DA SC, only 1 of 4 irradiated LEW grafts was accepted. However, if 1.5 x 10 8 DA SC harvested only 30 days after liver transplantation were transferred, only 2 of 5 irradiated LEW liver grafts were accepted. The serial second and third adoptive transfers of 1.5 x 10 8 DA LTS SC also resulted in the uniform acceptance of irradiated LEW livers. CONCLUSION: Regulatory cells that develop after the spontaneous acceptance of a LEW to DA liver transplant can serially transfer tolerance to new naive LEW liver allograft DA recipients. This "infectious tolerance" is dependent on the time of cell harvest after transplantation and on the cell dose given.     

Fibrosing alveolitis: CT-pathologic correlation

Computed tomography (CT) was performed within 10 days of open lung biopsy in nine patients with fibrosing alveolitis. One-centimeter collimation contiguous scans through the chest were obtained in all patients. Additional 1.5-mm collimation scans were obtained in the area in which lung biopsy was later performed in six patients. In seven patients, CT demonstrated patchy involvement of the lung parenchyma, areas with a reticular pattern being intermingled with areas of normal lung. The reticular pattern was associated with cystic spaces 2-4 mm in diameter and was more severe in the lung periphery. Histologically, the reticular pattern corresponded to areas of irregular fibrosis. One patient had diffuse honeycombing (2-20-mm cysts), and one had honeycombing only in the lung periphery. In all patients, CT clearly defined the architectural changes seen on open lung biopsy. These changes were much better seen on the 1.5-mm than on the 10-mm collimation scans. CT may be helpful in determining the pattern and distribution of lung involvement in patients with fibrosing alveolitis and in guiding the surgeon to the most appropriate area(s) for biopsy.     

Liver transplant recipients: portable duplex US with correlative angiography

Twenty patients, aged 4 months to 58 years, were evaluated for liver transplantation by duplex sonography, and 15 transplantations were completed; 42 postoperative examinations were performed. Sonographic findings were correlated with seven preoperative and five postoperative angiographic evaluations. Preoperative duplex US findings included tumors, portal vein occlusion, varices, biliary obstruction, and variant vascular anatomy. Postoperative findings included hepatic artery occlusion, portal vein occlusions (one with cavernous transformation), portal vein stenosis, biliary obstruction, intrahepatic and extrahepatic fluid collections, and air in the portal vein due to ischemic bowel. Use of angiography allowed confirmation of the vascular abnormalities and demonstrated evidence of rejection in patients with normal Doppler waveforms. Duplex sonography is a valuable portable technique for evaluating these patients and can be used in triage of patients requiring angiography.