A case of Campylobacter jejuni bacteremia in a renal transplant patient

Only 2 cases of Campylobacter bacteremia have been reported in renal transplant recipients, to our knowledge, with both resulting in significant morbidity and mortality. We present a case of a 56-year-old renal transplant recipient who presented with brief diarrheal illness followed by Campylobacter jejuni bacteremia. She remained asymptomatic for 5 days after initial presentation despite positive blood cultures. She was treated with levofloxacin for a total of 4 weeks and, fortunately, did not develop any complications. C. jejuni should be considered in the differential diagnosis as a potential cause of bacteremia in immunosuppressed renal transplant patients presenting with diarrheal illness.

Comparative pharmacokinetics and renal effects of cyclosporin A and cyclosporin G in renal allograft recipients

Cyclosporin G (CSG) has produced less nephrotoxicity than cyclosporin A (CSA) at equivalent doses in animal models. Conflicting results have been reported concerning differences in the pharmacokinetics of CSA and CSG in preclinical studies, and no data exist regarding the effect of steady-state oral administration of CSG on renal function in transplant patients or CSG-induced release of endothelin and nitric oxide (NO) in vivo. The objective of the study was to examine steady-state pharmacokinetic profiles of adult renal allograft recipients receiving CSA and CSG in relation to concentrations of endothelin-1 and NO2/NO3 in urine and plasma, creatinine clearance (Clcr), and urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG) 9 months after transplantation. Concentrations of CSA and CSG were measured in whole blood over a 12-hour dose interval by both a monoclonal and polyclonal fluorescence polarization radioimmunoassay for CSA. A metabolite fraction was defined as the numerical difference between the levels obtained at each time point by both assays. Patient groups were defined as follows: group 1: initial CSA (n = 6); group 2: initial CSG (n = 7); group 3: five of the seven patients in group 2 taking CSG subsequently undergoing conversion to CSA; group 4: the same five patients in group 3 restudied 1 month after 1:1 dosage conversion to CSA; and group 5: CSA groups 1 and 4 combined (n = 11). In group 1, the metabolite fraction accounted for 32% to 54% of the total measurable drug concentration at each time point, whereas in group 2, the metabolite fraction accounted for at most 10% to 15% of the total drug levels measurable by polyclonal fluorescence polarization radioimmunoassay. Although there were no significant differences in any of the mean pharmacokinetic parameters between groups using monoclonal fluorescence polarization radioimmunoassay, the normalized area under the concentration-time curve (NAUC) value was less in four of five patients after conversion from CSG to CSA, with a more variable and delayed time to reach peak concentration (tmax) but equivalent apparent oral clearance (Clpa) values. Clcr was found to change significantly with time in groups 1 and 5 but not in group 2, with CSA producing a more profound and sustained decrease than CSG. Endothelin-1 and NO2/NO3 levels in plasma and urine remained relatively constant after administration of both CSA and CSG, and there were no significant differences between groups 3 and 4 regarding mean endothelin-1 and NO2/NO3 concentrations in plasma, urinary release of endothelin-1 and NO2/NO3, and mean AUC of endothelin-1 and AUC of NO2/NO3. However, monoclonal NAUC correlated significantly with total urinary endothelin-1 within CSA groups 1 and 5 but not within CSG group 2. Metabolite NAUC correlated significantly with total urinary NAG within CSA group 1. Although limited by the small number of patients, this study suggests that 1) CSG may produce less of a reduction in Clcr over time after oral administration at steady state than does CSA, and 2) this beneficial effect of CSG may be in part due to decreased intrarenal release of endothelin-1, as urinary excretion of endothelin-1 seemed to correlate better with CSA than with CSG exposure.

Preemptive ganciclovir therapy in cytomegalovirus-seropositive renal transplants recipients

OBJECTIVE

To evaluate the efficacy, safety, and cost of preemptive ganciclovir therapy in cytomegalovirus (CMV)-seropositive renal transplant recipients treated with antilymphocyte antibody (ALA) preparations.

DESIGN AND SETTING

A prospective, randomized trial at a 650-bed tertiary medical center hospital.

PATIENTS

Forty consecutive CMV-seropositive renal allograft recipients who underwent transplantation between January 1992 and January 1994 and were treated with ALA for induction immunosuppression or acute rejection therapy.

MAIN OUTCOME MEASURES

The incidence and severity of CMV disease, length of hospitalization, and patient and allograft survival.

INTERVENTION

Cytomegalovirus infection prophylaxis by use of intravenous ganciclovir during ALA therapy was administered to 22 patients (group 1) and the results were compared with those obtained in 18 control patients who did not receive prophylaxis for CMV disease (group 2).

RESULTS

Preemptive ganciclovir therapy significantly reduced the incidence of CMV disease (P < .05) in CMV-seropositive renal transplant patients who were treated with ALA and was well tolerated. In addition, the cost of prophylactic therapy was offset by the decreased length of hospitalization observed in patients in group 1.

CONCLUSION

Preemptive ganciclovir therapy provides a cost-effective approach toward significantly improving the outcome of renal transplantation in CMV-seropositive patients treated with ALA.

Macrophage colony-stimulating factor and granulocyte-macrophage colony-stimulating factor stimulate the synthesis of plasminogen-activator inhibitors by human monocytes

Macrophage colony-stimulating factor (M-CSF or CSF-1) and granulocyte-macrophage CSF (GM-CSF) have been shown to increase human monocyte urokinase-type plasminogen-activator (u-PA) activity with possible consequences for cell migration and tissue remodeling; because monocyte u-PA activity is likely to be controlled in part also by the PA inhibitors (PAIs) made by the cell, the effect of M-CSF and GM-CSF on human monocyte PAI-2 and PAI-1 synthesis was investigated. To this end, elutriation-purified human monocytes were treated in vitro with purified recombinant human M-CSF and GM-CSF, and PAI-2 and PAI-1 antigen and mRNA levels measured by specific enzyme-linked immunosorbent assays and Northern blot, respectively. Each CSF could enhance the protein and mRNA levels of PAI-2 and PAI-1 at similar concentrations for each product. This similar regulation of monocyte PAI expression in response to the CSFs contrasted with that found for the effects of lipopolysaccharide, transforming growth factor-beta and a glucocorticoid. Therefore, PAIs may be modulating the effects of the CSFs on monocyte u-PA activity at sites of inflammation and tissue remodeling.

Contrasting effects of transforming growth factor-beta and IL-1 on the regulation of plasminogen activator inhibitors in human synovial fibroblasts

TGF-beta increased in a dose-dependent manner the production of plasminogen activator inhibitor-1 (PAI-1) in cultured human synovial fibroblast-like cells, as measured by ELISA. Significant increases in PAI-1 were first detected in cell supernatants within 4 h after cytokine addition. Increases were also observed in PAI-1 mRNA expression. IL-1 suppressed these increases in PAI-1 Ag and mRNA. In contrast, when PAI-2 levels were measured by ELISA, TGF-beta did not raise them but inhibited slightly the enhancement caused by IL-1 of PAI-2 Ag and mRNA. Therefore TGF-beta selectively stimulates the formation of one PAI; TGF-beta and IL-1 have opposing effects on PAI-1 and PAI-2 synthesis in the synovial cells. These findings are proposed to help define the control of fibrinolysis and tissue remodeling in the rheumatoid synovium.

Contrasting effects of transforming growth factor-beta and IL-1 on the regulation of plasminogen activator inhibitors in human synovial fibroblasts

TGF-beta increased in a dose-dependent manner the production of plasminogen activator inhibitor-1 (PAI-1) in cultured human synovial fibroblast-like cells, as measured by ELISA. Significant increases in PAI-1 were first detected in cell supernatants within 4 h after cytokine addition. Increases were also observed in PAI-1 mRNA expression. IL-1 suppressed these increases in PAI-1 Ag and mRNA. In contrast, when PAI-2 levels were measured by ELISA, TGF-beta did not raise them but inhibited slightly the enhancement caused by IL-1 of PAI-2 Ag and mRNA. Therefore TGF-beta selectively stimulates the formation of one PAI; TGF-beta and IL-1 have opposing effects on PAI-1 and PAI-2 synthesis in the synovial cells. These findings are proposed to help define the control of fibrinolysis and tissue remodeling in the rheumatoid synovium.

Regulation of plasminogen activator inhibitor-1 levels in human monocytes

The regulation of PAI-1 synthesis by elutriation-purified human monocytes was studied in vitro and compared to that for PAI-2. PAI-1 formation, as measured by ELISA, was upregulated by TGF-beta (> or = 1 ng/ml) and surprisingly down-regulated by LPS (100 ng/ml), particularly in the presence of TGF-beta; LPS elevated PAI-2 levels (ELISA) while TGF-beta reduced its basal levels and those in LPS-treated cultures. Concomitant changes in mRNA expression occurred. The glucocorticoid dexamethasone (10(-7) M) elevated PAI-1 and acted in concert with TGF-beta in this regard at both the antigen and mRNA levels; interleukin-4 (IL-4) (250 pM) failed to mimic the steroid in its regulation of PAI-1 formation. Since monocyte/macrophage PA activity is likely to be important in tissue remodeling and cell migration at sites of inflammation and in fibrinolysis, it is proposed from these studies that PAI-1, as well as the usually considered PAI-2, may be involved in the negative control of PA activity in this cell type. The synthesis of each PAI appears to be independently regulated.

Independent regulation of plasminogen activator inhibitor 2 and plasminogen activator inhibitor 1 in human synovial fibroblasts

OBJECTIVE

To study the plasminogen activator inhibitor(s) (PAI) produced in vitro by human synovial fibroblast-like cells.

METHODS

Human synovial cell explant cultures were established using cells from nonrheumatoid donors. PAI-2 and PAI-1 antigens were measured by enzyme-linked immunosorbent assay, and messenger RNA (mRNA) levels were determined by Northern blot.

RESULTS

The synovial fibroblasts produced both PAI-2 and PAI-1. Interleukin-1 (IL-1) increased PAI-2 but decreased PAI-1 formation, both at the protein and the mRNA levels. Using cyclooxygenase inhibitors, evidence was obtained that an endogenous cyclooxygenase product(s) in the IL-1-treated cultures inhibited formation of both PAIs; exogenous prostaglandin E2 (10(-7) M) reversed the effect of cyclooxygenase inhibition. The glucocorticoid dexamethasone (10(-6) to 10(-7) M) inhibited IL-1-stimulated PAI-2 formation but reversed the suppressive effect of IL-1 on PAI-1 production.

CONCLUSION

PAI-2 formation and PAI-1 formation can be regulated independently in human synoviocytes, illustrating the complexity of the modulation of the net PA activity expressed by these cells.