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Biomedical subjects

R A Krom

Publications and source records attributed to R A Krom.

At least 19 recordsLinked to original sources

Relevance and risk factors of enterococcal bacteremia following liver transplantation.

To analyze the clinical characteristics of and identify specific risk factors for enterococcal bacteremia following liver transplantation, we performed a study in 405 consecutive liver transplantation recipients prophylaxed with a selective bowel decontamination regimen. Seventy enterococcal bacteremias in 52 patients were identified. Enterococcus faecalis (50) outnumbered Enterococcus faecium isolates (18), and 49% of enterococcal bacteremias were polymicrobial. Biliary tree complications were present in 34% of enterococcal bacteremias. Of the 15 deaths (29%) among the patients with enterococcal bacteremia, 4 were directly associated with enterococcal bacteremia. In a multivariate analysis, Roux-en-Y choledochojejunostomy (P=0.005), a cytomegalovirus-seropositive donor (P=0.013), prolonged transplantation time (P=0.02), and biliary stricturing (P=0.016) were identified as significant risk factors. Other risk factors identified in a univariate analysis included primary sclerosing cholangitis (P=0.009) and symptomatic cytomegalovirus infection (P=0.008). Enterococcal bacteremia is a frequent infectious complication in liver transplantation recipients receiving selective bowel decontamination. Its association with cytomegalovirus and biliary tree abnormalities suggest specific areas for prophylactic intervention.

Anastomosis, Roux-en-Y

Neuromuscular complications associated with liver transplantation.

We studied neuromuscular complications in a cohort of 520 patients with liver transplantation. Perioperative mononeuropathy developed in 9 patients. The peroneal nerve, radial nerve, and cutaneous branch of the femoral nerve were affected in 2 patients each. Two patients had herpes zoster-associated radiculopathy, and 1 patient had Horner's syndrome. Recovery was good in most patients. In 7 patients, severe quadriplegia complicated the perioperative course. In 5 patients, electrophysiologic studies suggested acute necrotic myopathy, and muscle biopsy specimens showed evidence of rhabdomyolysis in 1 patient. Outcome in survivors was good, all recovering completely. We conclude that neuromuscular complications in liver transplantation are uncommon (less than 1%) and do not significantly contribute to morbidity. Mononeuropathies may have iatrogenic perioperative causes, and rhabdomyolysis may be an important cause of generalized muscle weakness after liver transplantation.

Adult

Granulocyte accumulation in the transplanted liver does not correlate with clinical and histologic evidence of dysfunction.

RATIONALE AND OBJECTIVES: To evaluate the role of granulocytes in reperfusion injury after liver transplantation. The authors injected radiolabeled granulocytes to determine if human liver graft outcome could be correlated with granulocyte accumulation. MATERIALS AND METHODS: Pure granulocyte suspension was prepared from eight patients 12 to 24 hours after orthotopic liver transplantation. The granulocytes were labeled with indium-111 (111In) oxine and reinjected. Total body radionuclide images were performed. Liver uptake of granulocytes was compared with biochemical and histologic evidence of liver injury. RESULTS: No correlation was found between liver uptake of granulocytes, as measured by geometric mean counts, and the biochemical or histologic measures of liver injury. Liver uptake of 111In was 9.6% for the patient who had liver dysfunction and 10.4% mean of the study group. This technique did not detect early signs of liver dysfunction. CONCLUSIONS: This investigation supports the premise that granulocytes do not play a major role in reperfusion injury of the newly transplanted liver graft.

Biopsy

Organ-specific patterns of donor antigen-specific hyporeactivity and peripheral blood allogeneic microchimerism in lung, kidney, and liver transplant recipients.

Although their relative importance and interaction are unclear, donor antigen(Ag)*-specific hyporeactivity and allogeneic microchimerism have been associated with improved long-term graft outcome and a lower incidence of chronic rejection in solid organ transplant recipients. We have postulated that a critical level of donor antigen, for a critical time period, is necessary to develop and maintain donor antigen-specific hyporeactivity; both the level and the time may differ by organ transplanted. In our current study, we tested donor antigen-specific hyporeactivity and peripheral blood allogeneic microchimerism in liver and kidney recipients and compared these values with our previous findings in lung recipients. We tested 25 liver recipients at 12 to 29 months posttransplant: 10 (40%) had developed donor antigen-specific hyporeactivity; 5 (20%), peripheral blood allogeneic microchimerism. For all but 1 of the chimeric and hyporeactive recipients, the level of donor cells was very low (< 1:20,000). Five hyporeactive recipients and all 15 donor antigen-responsive recipients did not have detectable levels of peripheral blood microchimerism. No chronic rejection has developed in any of these recipients to date--however, a lower incidence of acute rejection was observed for those recipients with donor antigen-specific hyporeactivity (30% versus 60% without) or with peripheral blood allogeneic microchimerism (20% versus 55% without) (P = ns). These results differ from our previous findings in 19 lung recipients: at 12 to 18 months posttransplant, 35% of them had developed donor antigen-specific hyporeactivity; 47%, peripheral blood allogeneic microchimerism. All donor antigen-specific hyporeactivity recipients as well as some donor antigen-responsive recipients had peripheral blood allogeneic microchimerism. We expanded our current study to include 26 recipients and a quantitative estimate of the level of allogeneic microchimerism. We observed that the hyporesponsive recipients tended to have higher levels of donor cells in their peripheral blood (> 1:6,000) than did the responsive recipients. We previously reported that 22% of kidney recipients had developed donor antigen-specific hyporeactivity at 12 to 18 months posttransplant. In our current study of 33 kidney recipients, we observed peripheral blood allogeneic microchimerism in 7 (21%) at 12 to 18 months posttransplant. The level of donor cells was very low (approximately 1:75,000), with no correlation between donor antigen-specific hyporeactivity and peripheral blood allogeneic microchimerism at the time point tested. These studies emphasize the organ-specific nature of the development of donor antigen-specific hyporeactivity and the persistence of peripheral blood allogeneic microchimerism. Donor antigen-specific hyporeactivity correlates with very low levels of donor cells in liver recipients, while a higher critical level of donor cells is important in lung recipients. Additional sequential early posttransplant studies are necessary to further define the possible interrelationship between donor antigen and the development and maintenance of donor antigen-specific hyporeactivity.

Antigen Presentation

Loss of nocturnal blood pressure fall after liver transplantation during immunosuppressive therapy.

Hypertension, which develops after organ transplantation during immunosuppression with cyclosporine (CSA), is often associated with a loss of nocturnal decrease in blood pressure. Few data correlate circadian blood pressure patterns before transplant with those observed at fixed time points after transplant, or address the role of alternate immunosuppressive agents such as FK506. FK506 is unrelated structurally to CSA and less often leads to hypertension early after transplant. The present study compared nocturnal blood pressure patterns in patients with end-stage liver disease (ESLD) before transplant to those of transplant recipients receiving either FK506 (0.15 mg/kg/day) plus prednisone or CSA (2 to 3 mg/kg/day) plus prednisone and azathioprine after orthotopic liver transplantation. Overnight ambulatory blood pressure profiles were studied in 13 pretransplant ESLD patients and in 34 patients (FK506: n = 13; CSA: n = 21) treated with different steroid doses (24 +/- 11 mg/day FK506; 34 +/- 3 mg/day CSA), according to protocol, 4 weeks (range, 2 to 7 weeks) after liver transplant. Mean blood pressure and heart rate values from awake and nocturnal 5-h time blocks were compared to 13 normotensive control subjects. Patients with ESLD were normotensive and maintained a normal nocturnal blood pressure fall (125 +/- 3/74 +/- 2 mm Hg awake; 109 +/- 3/60 +/- 2 mm Hg nocturnal). Awake ambulatory blood pressures were higher in CSA patients than in FK506 patients (148 +/- 3/95 +/- 2 v 128 +/- 3/78 +/- 2 mm Hg, respectively; P < .01), despite reduced glomerular filtration rates in both transplant groups. Both immunosuppressive regimens led to a loss of nocturnal blood pressure fall, as compared to ESLD patients or normotensive controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure

A prospective comparison of molecular diagnostic techniques for the early detection of cytomegalovirus in liver transplant recipients.

Forty-one consecutive liver transplant recipients were studied by polymerase chain reaction (PCR) of serum and peripheral blood mononuclear cells, reverse transcription (RT)-PCR of peripheral blood mononuclear cells, and viral blood culture for symptomatic cytomegalovirus (CMV) infection. The techniques were also used to predict the occurrence of CMV infection. For diagnosis of symptomatic CMV infection, the sensitivity and specificity of the different techniques were as follows: PCR of serum, 100% and 45%; RT-PCR, 25% and 97%; PCR of peripheral blood mononuclear cells, 83% and 35%; and blood culture, 83% and 86%, respectively. PCR of serum was positive in 83% of subjects with symptomatic infection before onset compared with 17% positive by blood culture. While viral blood culture was the best technique for the diagnosis of symptomatic CMV infection, PCR of serum was best at predicting the development of symptomatic CMV infection.

Cytomegalovirus

OKT3 treatment for allograft rejection is a risk factor for cytomegalovirus disease in liver transplantation.

The role of OKT3 monoclonal antibody administration was studied as a risk factor for symptomatic cytomegalovirus (CMV) infection in 229 consecutive liver transplant recipients not receiving specific CMV prophylaxis. Twenty-six patients (11.4%) received OKT3 and 17 of them developed CMV infection, 11 (4.8%) being symptomatic. OKT3 use was a significant risk factor for symptomatic CMV infection by both univariate (relative risk [RR], 2.9; 95% confidence interval [CI], 1.5-5.8; P = .002) and multivariate time-dependent (RR, 3.4; 95% CI, 1.7-7.1; P = .001) analyses. A subgroup analysis revealed that OKT3 use was a significant risk factor for symptomatic CMV infection in CMV-seropositive but not seronegative recipients. OKT3 therapy for steroid-resistant rejection is a risk factor for symptomatic CMV infection in liver transplant recipients who are seropositive for CMV before transplantation. This group should be targeted for antiviral prophylaxis when OKT3 antirejection therapy is used.

Cytomegalovirus Infections

Neurotoxicity in liver transplant recipients with cyclosporine immunosuppression.

We studied the clinical features, blood levels of cyclosporine, and neuroimaging findings in 46 patients with cyclosporine neurotoxicity after liver transplantation. The clinical presentation of cyclosporine neurotoxicity was characterized by tremulousness and restlessness in all patients and was associated with acute confusional state and psychosis in 20 patients, seizures in eight, speech apraxia or action myoclonus speech in three, and cortical blindness in two. In 35 patients, cyclosporine neurotoxicity occurred during IV treatment. Neuroimaging studies showed only minor white matter abnormalities in two patients despite dramatic clinical presentations, including speech difficulties, seizures, and cortical blindness. In only 19 of 31 patients (61%) did trough levels of cyclosporine suggest neurotoxicity. Neurologic findings were reversible in all patients after cyclosporine was withheld and then given in lower dosage. In three patients, substituting FK 506 did not result in neurotoxicity.

Adolescent

Renal sodium handling with cyclosporin A and FK506 after orthotopic liver transplantation.

Hypertension is common after orthotopic liver transplantation and may be due, in part, to cyclosporin A-induced renal dysfunction and/or enhanced proximal tubular sodium reabsorption. To determine whether enhanced proximal tubular sodium reabsorption is central to the development of posttransplant hypertension, measurements of renal hemodynamics and fractional clearances of lithium and sodium were compared 1 month after orthotopic liver transplantation in previously normotensive patients receiving either cyclosporin A (N = 24) or FK506 (N = 18), an immunosuppressive agent that is structurally unlike cyclosporin A and that has a lower reported incidence of hypertension. Median prednisone doses were 20 and 13 mg/day in the cyclosporin A and FK506 groups, respectively (P < 0.05). At 1 month, mean arterial blood pressure was higher in the cyclosporin A versus the FK506 group: 108 +/- 2 versus 95 +/- 3 mm Hg (P < 0.05). GFR, RBF, and renal vascular resistance were not different between the two groups: 59 +/- 4 and 53 +/- 5 mL/min per 1.73 m2, 439 +/- 28 and 440 +/- 41 mL/min per 1.73 m2, and 22,429 +/- 1,822 and 22,977 +/- 3,506 dyne s/cm5 per 1.73 m2, respectively. Fractional lithium excretion was similar in the cyclosporin A and FK506 groups: 19.9 +/- 2.2 and 19.4 +/- 2.0% (P = not significant) although both values were lower than those of normal controls (25.5 +/- 1.1%) (P < 0.05). Fractional sodium excretion was 2.7 +/- 0.3 and 2.3 +/- 0.4% in the cyclosporin A and FK506 groups, respectively (P = not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure

Intracerebral hemorrhage in liver transplant recipients.

OBJECTIVE: To analyze possible causative mechanisms for intracranial hemorrhage after orthotopic liver transplantation. DESIGN: We conducted a retrospective survey of medical records and a case-control comparison in patients who had undergone liver transplantation during the period 1986 through 1992. MATERIAL AND METHODS: In a group of 8 patients with intracranial hemorrhage after orthotopic liver transplantation and a control series of 207 patients who had undergone liver transplantation but did not have intracranial hemorrhage, we summarized pertinent clinical and laboratory data and statistically analyzed potential risk factors for hemorrhage. RESULTS: In the eight study patients, intracerebral hematomas were located in the parietal or frontal lobe in six, the cerebellum in one, and the putamen in one. Autopsy demonstrated a Candida-associated mycotic aneurysm in one of the eight patients, and one had disseminated aspergillosis. No statistically significant differences in thrombocytopenia, hypertension, extracranial bleeding sites, or cyclosporine-related neurotoxicity were found when these patients were compared with the control series. Bacteremia or fungemia was found in five of the eight patients with intracerebral hemorrhages (62%) but in only 11% of the control group (P = 0.03; Fisher's exact test). CONCLUSION: Overwhelming infections, thrombocytopenia, or both may have a role in intracerebral hemorrhage after liver transplantation.

Adolescent

Early cellular rejection after orthotopic liver transplantation correlates with low concentrations of FK506 in hepatic tissue.

We have previously reported that low hepatic tissue cyclosporine levels correlate with early cellular rejection after liver transplantation. The aim of this study is to determine whether there is a similar relationship in patients treated with FK506. Twenty-five liver biopsies were performed in 10 patients immunosuppressed with FK506 without cellular rejection: day 7 = 10; day 14 = 3; day 21 = 9; day 28 = 1; day 35 = 1; and day 42 = 1. These 10 patients without cellular rejection were compared with 7 patients immunosuppressed with FK506 with cellular rejection who underwent a total of 23 liver biopsies, including 9 biopsies that showed rejection: day 7 = 4; day 14 = 2; day 21 = 1; day 28 = 1; and day 49 = 1. There was no significant difference between the nonrejection and current rejection groups in the median plasma concentration of FK506, 0.9 ng/mL versus 0.9 ng/mL (P = .50). In contrast, the median hepatic tissue concentration of FK506 was significantly higher in the nonrejection group than it was in the current rejection group, 144 ng/g versus 48 ng/g (P = .02). In the current rejection group, 7 of 9 hepatic tissue concentrations of FK506 were < 100 ng/g, and in the nonrejection group, 18 of 25 hepatic tissue concentrations were > 100 ng/g. Low hepatic tissue concentrations of FK506 correlate with the occurrence of early cellular rejection after liver transplantation, in contrast to plasma concentrations of FK506. A hepatic tissue concentration of FK506 < 100 ng/g is 78% sensitive and 72% specific for cellular rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Failure of hepatopulmonary syndrome to resolve after liver transplantation and successful treatment with embolotherapy.

The hepatopulmonary syndrome is an uncommon accompaniment of chronic liver disease. The outcome of this disorder after orthotopic liver transplantation is variable. We describe a patient with the hepatopulmonary syndrome who underwent orthotopic liver transplantation for autoimmune hepatitis. Her platypnea and orthodeoxia failed to improve postoperatively. Pulmonary angiography showed large pulmonary arteriovenous shunts that were successfully treated with coil embolotherapy.

Adult

The role of portosystemic shunts for variceal bleeding in the liver transplantation era.

OBJECTIVE: To review our experience with portosystemic shunts during the era of liver transplantation at the Mayo Clinic to provide insight into the selection of patients for these procedures. DESIGN: We reviewed the charts of a cohort of 57 patients who underwent portosystemic shunting between 1985 and 1990 for the management of variceal bleeding. A follow-up survey by letter and telephone was also conducted. SETTING: The Mayo Clinic, a tertiary referral center. PATIENTS: These patients were not considered transplantation candidates at the time of the shunt because of active alcoholism, extensive portal vein thrombosis, coexistent myelodysplastic syndromes, or malignant neoplasms. INTERVENTION: Portosystemic shunts; the exact type was at the surgeon's discretion. OUTCOME: Survival after shunt surgery among patients with various liver diseases. RESULTS: Twenty-two patients died during follow-up after being shunted for bleeding, and one of the shunted patients subsequently required liver transplantation. Comparison of Kaplan-Meier survival curves between various groups of patients indicated that patients who were actively alcoholic had a poorer chance of survival (P < .003) than did those who were abstinent. Patients with portal vein obstruction or chronic cholestatic liver disease appeared to do better after shunt surgery than did patients with other causes of portal hypertension. Other factors such as age, Child-Pugh score, or presence of malignant neoplasms did not reliably predict outcome from portosystemic shunts. CONCLUSIONS: In well-selected patients who may not be deemed candidates for liver transplantation, portacaval shunts can be effectively employed to prevent bleeding from esophageal varices that are resistant to obliteration by sclerotherapy.

Cause of Death

FK506-induced neurotoxicity in liver transplantation.

We report FK506-induced neurotoxicity in 14 of 44 consecutive patients following orthoptic liver transplantation. In 10 of these 14 patients, postural hand tremors were found in the first weeks following surgery, transient apraxia of speech in 3, and generalized tonic-clonic seizures were noted in 2 patients. Other manifestations included nightmares, agitation, and acute delirium. Reduction of the FK506 dose resulted in resolution of symptoms, but in 1 patient mild speech difficulties and in 3 patients a fine tremor remained. Blood and plasma levels of FK506 were similar in patients with and without neurotoxicity. FK506 neurotoxicity in patients with liver transplantation commonly results in transient neurological manifestations. The incidence of neurotoxicity in FK506 is dramatically reduced in maintenance doses of 0.075 mg/kg twice a day.

Adult