Lack of utility of intestinal fatty acid binding protein levels in predicting intestinal allograft rejection

INTRODUCTION

The enterocyte-specific protein, intestinal fatty acid binding protein (I-FABP), is detectable in serum only after intestinal injury. Previous studies in animals suggest that I-FABP might be a useful marker of intestinal allograft rejection.

MATERIALS AND METHODS

I-FABP was repetitively measured in nine intestinal transplant recipients and correlated with findings of surveillance endoscopy.

RESULTS

Average interval between I-FABP determination and biopsy was 3.4 days (SD=4.2 days). Average number of rejection episodes per patient totalled 1.6+/-1.2. General linear modeling demonstrated no tendency for increases in serum FABP to precede histologic graft rejection (P=0.263). Restriction of the analysis to I-FABP determinations 1 day before or on the day of biopsy failed to affect these results. Minor increases in I-FABP were often associated with histologically normal grafts, whereas rejection often occurred when I-FABP was not detectable.

DISCUSSION

Serum I-FABP levels do not predict clinical intestinal allograft rejection.

Cyclosporine challenge test revisited: does it predict outcome after solitary pancreas transplantation?

BACKGROUND

The selection of patients for solitary pancreas transplantation (PTA) requires identification of individuals who will not develop acute renal dysfunction in response to immunosuppressants. A cyclosporine challenge test (CCT) was developed to predict post-PTA kidney dysfunction secondary to calcineurin inhibitor immunosuppressants. We now report on the long-term follow-up of patients who received a PTA after undergoing a CCT.

METHODS

Twelve potential PTA recipients were administered cyclosporine A (CsA) for 6 wk. Creatinine clearance (CrCl) was measured at 2, 4, and 6 wk. Those who did not fail the CCT received PTA. Baseline and post-transplant CrCl were retrospectively evaluated in the original cohort and in a group of matched patients who received PTA without a CCT.

RESULTS

Of the original 12 recipients evaluated with the CCT, 6 received PTA. CrCl was followed for a mean of 45.8 months. Of the 4 who remained alive, 2 went on to develop renal failure (CrCl < 30 mL/min) at 18 and 65 months post-transplant. The baseline CrCl was higher in PTA recipients who had not been selected to be studied with CCT than those that were (117 +/- 32 vs 78 +/- 13 mL/min). By 12 months post-PTA, the CrCl was no longer different between the groups selected to be screened with CCT and those that were not.

CONCLUSIONS

CCT may help predict risk for short-term changes in renal function (< 18 months) in response to CsA. CCT may be most helpful in candidates for PTA with borderline renal insufficiency (60-80 mL/min).

Reproductive hormones after pancreas transplantation

BACKGROUND

Reproductive hormone function after pancreas transplantation (PTX) is unknown as it has not been studied.

METHODS

We prospectively studied PTX recipients to determine changes in reproductive hormones after PTX. Testosterone or estradiol, leutinizing hormone, follicle stimulating hormone, and prolactin were determined before and 1 year after PTX in 23 patients (10 women, 13 men) followed for more than 1 year after PTX. Of these, 11 received simultaneous kidney-PTX; 8 PTX only; and 4, PTX after kidney. Average age was 38.4+/-1.6 years and average duration of diabetes was 24.5+/-1.3 years. Nine (four women, five men) patients had been on dialysis pre-PTX. Sixteen of 23 patients were treated with cyclosporine and seven with FK-506 along with prednisone and azathioprine post-PTX.

RESULTS

Mean testosterone in men was normal pre- and post-PTX. Two men had secondary hypogonadism pre-PTX with resolution in one and persistence in the other post-PTX. Five of the ten women had evidence of hypogonadism pre-PTX: three had primary hypogonadism and two had secondary hypogonadism. Post-PTX, 7 of 10 women had abnormal reproductive hormones: 4 had primary hypogonadism, 2 had secondary hypogonadism, and 1 developed hyperestrogenemia with elevated estradiol (482 pg/ml) and leutinizing hormone (41 IU/liter). Mean prednisone dose and cyclosporine trough level were higher in the women than the men (P<0.05). No cases of secondary hypogonadism that developed or resolved post-PTX were related to changes in prolactin, renal function, or hyperglycemia.

CONCLUSIONS

Women are more likely than men to have reproductive hormone abnormalities pre- and post-PTX and the causes may be multiple.

Nitrate and nitrite concentrations in human saliva for men and women at different ages and times of the day and their consistency over time

Salivary nitrite arises from nitrate and is the main source of gastric nitrite, a precursor of carcinogenic N-nitroso compounds. We examined nitrate and nitrite levels in unstimulated saliva from subjects consuming low-nitrate low-vitamin C diets. When saliva was collected from six men at nine times of the day (Experiment 1), night time nitrite levels were significantly higher than day time values and nitrite varied more than nitrate. When saliva was collected from 29 subjects aged 19-37 or 60-84 years at four times of the day during 1991-1993 (Experiment 2), all older subjects and older men had significantly higher nitrite levels than the corresponding younger subjects, night time nitrite levels in men were significantly raised, and nitrate and nitrite levels in the same samples were closely correlated. Saliva was collected at 6.00 a.m. on two successive days in 1997 from 16 subjects who had collected saliva in 1991-1993 (Experiment 3). Nitrate and nitrite levels on day 1 of experiment 3 were closely correlated with those on day 2. Nitrate and nitrite levels on days 1 and 2 of Experiment 3 were correlated with the corresponding parameters in Experiment 2 with P = 0.04 and 0.08 for day 1, and 0.10 and 0.28 for day 2, respectively. Hence, saliva nitrite levels rose at night and were higher in older people, especially older men, and saliva nitrate and nitrite levels varied little from day to day, but varied more after 4-6 years.

Disaccharidase activities and fat assimilation in pediatric patients after intestinal transplantation

BACKGROUND

Intestinal transplantation has become an accepted therapy for short bowel syndrome and other types of intestinal failure. In order to assess digestive capabilities and feeding practices in a group of 22 pediatric patients after intestinal transplantation, we assessed mucosal disaccharidase activities and assimilation of total dietary lipid and vitamin E. Twelve of the patients had undergone contemporaneous liver transplantation.

METHODS

Mucosal biopsies were assayed for disaccharidase activities between 15 and 412 days after transplantation in 7 of the 22 when all were receiving some enteral nutrition and were free of rejection. Coefficients of lipid absorption were determined in those patients receiving total enteral feeding (two-thirds polymeric/one-third elemental) between 43 and 1032 days after transplantation; oral vitamin E tolerance tests were done at about the same time.

RESULTS

Activities of lactase, sucrase, maltase, and palatinase consistently exceeded reference ranges (P<0.05). Mean coefficient of lipid absorption equaled 86+/-12% and was not influenced by duration of time after transplantation. No patient required dietary lipid restriction. No significant absorption of vitamin E was demonstrated until 160 days after transplantation. Vitamin E absorption did correlate with length of time elapsed after surgery (r=0.64, P<0.0011).

CONCLUSIONS

The results of this investigation show that, in the absence of histologic or clinical indications of allograft rejection, pediatric intestinal transplant recipients do not have primary disaccharidase deficiencies. Similarly, absorption of usual dietary lipid content is adequate once weaning from parenteral nutrition is complete. In contrast, early assimilation of vitamin E is poor. Vitamin E absorption subsequently improves, but the mechanism is obscure.

Autologous hematopoietic stem-cell transplantation for relapsed or refractory Hodgkin's disease in children and adolescents

PURPOSE

To determine the treatment outcome and clinical factors that are of prognostic significance for children and adolescents with relapsed or refractory Hodgkin's disease (HD) who received treatment with high-dose chemotherapy and autologous hematopoietic stem-cell transplantation (HSCT).

PATIENTS AND METHODS

Fifty-three consecutive children and adolescents 21 years of age or younger with relapsed or refractory HD underwent HSCT.

RESULTS

At day 100 after transplantation, 29 patients (55%) were in a complete remission or maintained a continuous complete response, six (11%) had a partial response, and 11 (21%) failed to respond or had progressive disease. The failure-free survival (FFS) at 5 years was 31%, and overall survival was 43%. Twenty-one patients died of progressive HD, and nine died secondary to transplantation-related complications, including two secondary leukemias. Prognostic factors important for FFS were normal pretransplantation lactate dehydrogenase levels (5-year FFS = 42%), compared with patients with elevated LDH levels (5-year FFS = 0%) (P < .001), and disease sensitivity at the time of HSCT with FFS in untreated relapse, sensitive disease, and resistant disease 44%, 35%, and 9%, respectively (P = .06). There was no statistically significant difference in FFS or overall survival between age subgroups that were analyzed (< 13, 13 to 18, 19 to 21) or in comparison with an adult cohort.

CONCLUSION

HSCT is an effective treatment modality that can result in long-term cures and should be considered for children and adolescents with relapsed HD.

Ketamine inhibits the proinflammatory cytokine-induced reduction of cardiac intracellular cAMP accumulation

The proinflammatory cytokines, including tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma), are increased in heart failure and sepsis, clinical conditions for which the IV anesthetic ketamine is useful. The proinflammatory cytokines cause beta-adrenergic receptor (betaAR) hypofunction secondary to reduced function of the enzyme adenylylcyclase (AC). In this study, we evaluated the effect of ketamine alone, TNF-alpha and IFN-gamma, and ketamine plus TNF-alpha and IFN-gamma, on isoproterenol (ISO, a betaAR agonist) and forskolin (FSK, an activator of AC)-induced intracellular accumulation of cAMP. An in vitro culture of a rat heart cell line (H9c2) was labeled with [3H]adenine to produce [3H]ATP, and we measured the intracellular accumulation of [3H]cAMP after stimulation with ISO or FSK to convert the [3H]ATP to [3H]cAMP. Pretreatment with either cytokine alone did not significantly affect ISO or FSK-induced intracellular cAMP accumulation, whereas the combination of TNF-alpha and IFN-gamma caused a significant (P < 0.05 compared with untreated cells) reduction. Pretreatment with ketamine caused a significant (P < 0.05 compared with untreated cells) increase in ISO or FSK-induced cAMP accumulation. Pretreatment of the H9c2 cells with ketamine, plus the combination of TNF-alpha and IFN-gamma, inhibited the reduction of ISO or FSK-induced intracellular cAMP accumulation caused by the proinflammatory cytokines alone. These results demonstrate that the combination of the proinflammatory cytokines TNF-alpha and IFN-gamma reduce poststimulation (ISO or FSK) intracellular cAMP accumulation. This action of the proinflammatory cytokines is consistent with the observation of betaAR hyporesponsiveness to betaAR agonist therapy in sepsis and heart failure. Ketamine augments the poststimulation cAMP accumulation in H9c2 cells while inhibiting the cytokine-induced reduction of cAMP accumulation. This may partly explain the improvement in cardiac function after ketamine use in clinical conditions known to have increased systemic levels of proinflammatory cytokines, such as sepsis and heart failure.

IMPLICATIONS

Tumor necrosis factor-alpha and interferon-gamma reduced poststimulation intracellular cAMP levels, whereas ketamine inhibits this action of the proinflammatory cytokines. Because cAMP is the second messenger for the beta-adrenergic receptor, this may be a mechanism for improved blood pressure and cardiac output in sepsis and heart failure after ketamine use.

Effect of ascorbic acid dose taken with a meal on nitrosoproline excretion in subjects ingesting nitrate and proline

We determined the dose of ascorbic acid (ASC) given to subjects with a standard 400-calorie meal that inhibited N-nitrosoproline (NPRO) formation when we gave 400 mg of nitrate one hour before and 500 mg of L-proline with the standard meal. Volunteers consumed their normal US diets but restricted their intakes of nitrate, proline, NPRO, and ASC. NPRO and N-nitrososarcosine (NSAR) were determined in the 18-hour urines by methylation followed by gas chromatography-thermal energy analysis. Mean NPRO yields were 10.7, 41.9, 33.2, 22.3, and 23.1 nmol for groups of 9-25 subjects taking proline alone, proline + nitrate, and proline + nitrate + 120, 240, and 480 mg of ASC, respectively. There was a significant trend to lower NPRO yields as the ASC dose was raised. These results correspond to inhibitions by ASC of 28%, 62%, and 60%, respectively. Pairwise comparison showed that each group taking ASC formed significantly less NPRO than the group given only proline + nitrate. Mean NSAR yields were 9.0 nmol when proline alone was taken and 16.9-24.0 nmol when proline + nitrate + ASC was taken, with no trend to increase as the ASC dose was raised. However, NPRO and NSAR yields in individual urines were correlated with each other. We concluded that 120 mg of ASC taken with each meal (360 mg/day) would significantly reduce in vivo nitrosamine formation, similar to tests by Leaf and co-workers (Carcinogenesis 8, 791-795, 1987) in which the reactants were taken between meals. The inhibitory dose of ASC may be < 120 mg/meal when doses of nitrate and proline are not taken.