Transforming growth factor-beta levels in human allograft chronic fibrosis correlate with rate of decline in renal function.

BACKGROUND: Long-term renal transplant function is limited primarily by a progressive scarring process loosely termed "chronic rejection, chronic allograft nephropathy, or allograft fibrosis." Although the etiology of transplant fibrosis is uncertain, several possible factors including chronic cyclosporin A (CsA) exposure may contribute to its pathogenesis. CsA stimulates renal fibrosis perhaps through the induction of the potent pro-sclerotic growth factor, transforming growth factor beta (TGFbeta). Previously, we demonstrated that, in human transplant biopsies, acute CsA toxicity but not acute tubular necrosis is associated with elevated levels of renal TGFbeta protein. We now examine whether long-term CsA treatment (>1 year) is associated with elevated levels of intra-allograft TGFbeta and whether heightened expression of TGFbeta is clinically significant. METHODS: Using immunohistochemical techniques, we determined the relative level of expression of intrarenal TGFbeta protein in transplant biopsies. We studied biopsies obtained from 40 CsA-treated patients that were diagnosed as having chronic allograft fibrosis. Biopsies were scored as having minimal or high levels of TGFbeta. RESULTS: Seventy-two percent of patients expressed high levels of intra-allograft TGFbeta. This group of patients lost renal function at an average rate of -19.5+/-17.3 ml/min/year. In contrast, patients with minimal or no TGFbeta expression experienced a decline of only -6.2+/-4.1 ml/min/year (P=0.01). CONCLUSIONS: These results suggest that the majority of CsA-treated patients with biopsy proven chronic fibrosis have elevated levels of intra-graft TGFbeta that correlates with an increased rate of decline in renal function.

Steroid withdrawal in kidney transplant recipients: is it a safe option?

The long-term side effects of lifelong steroid immunosuppression are well documented, therefore, steroid withdrawal (SW) if safe would clearly be of benefit. From 1987-1996, 470 kidney transplants were performed at our institution. During this time period, steroid withdrawal was offered to a select group of patients (n = 43) who were at least 1 year post transplant (27.6 +/- 12.0 months, 15-64 months), had stable graft function and had experienced only mild episodes of rejection in the postoperative period. Informed consent was obtained from all participants. Twenty-five patients were male and 18 were female. The mean age at time of transplantation was 42.4 +/- 14.1 years (17-65 years). There were 28 cadaveric renal transplants (CRT), 10 living related kidney transplants (LRT) and 5 simultaneous kidney-pancreas transplants (SPK). Maintenance immunosuppression in all patients consisted of CSA 3-5 mg/kg, and AZA 1-2 mg/kg. Twenty-nine patients (67%) have remained off steroids with good renal function for 13-59 months (38.3 +/- 11.0). Steroids were restarted in 14/43 (32%) patients 1-36 months post SW (13.3 +/- 11.0 months). Eight of these 14 patients had a rise in creatinine and biopsy proven rejection, 5 of whom responded to reinstitution of steroid immunosuppression, and have stable renal function (CR = 2.0 +/- 0.4) 41-53 months (45 +/- 4.0 months) post SW. Three (7%) patients lost their allograft. One was a SPK recipient who retained good pancreatic function and subsequently received a successful 2nd kidney transplant. The other 2 patients died awaiting retransplantation. Steroids were recommenced in 6/14 patients who did not develop rejection for inability to tolerate CSA/AZA (2), anxiety (2) or recurrent disease (2). In the majority of our patients, (93%) SW did not result in immunologic graft loss. A graft loss of 7% (3) is not significantly different from the expected graft loss in a kidney transplant recipient population over a time period of 9 years. Therefore, we feel that with careful monitoring steroid withdrawal can be safely accomplished in select patients.

Recombinant human and mouse purple acid phosphatases: expression and characterization.

The mammalian purple acid phosphatases (also called tartrate-resistant acid phosphatases) are expressed primarily in actively resorbing osteoclasts and activated macrophages. The enzymes are characterized by the presence of a binuclear iron center at the active site. Recent studies on transgenic mice lacking purple acid phosphatase implicate the osteoclast enzyme in both bone resorption and bone mineralization. To characterize the mammalian enzymes in more detail, particularly with respect to their substrate specificity at the low pH of the osteoclastic resorptive space (2.5-3), we have purified the recombinant human and mouse enzymes from baculovirus-infected insect cells. The properties of the recombinant mouse enzyme are compared with those of the nonrecombinant enzyme isolated from mouse spleen. The kinetics of hydrolysis of the substrates p-nitrophenyl phosphate, phosphotyrosine, and pyrophosphate and a phosphotyrosyl peptide by the recombinant human and mouse enzymes and the nonrecombinant mouse and pig enzymes were analyzed. For all the enzymes the ratio k(cat)/Km was typically approximately 10(6) M(-1) s(-1) and was higher at pH 2.5 than at 4.9. The increase was attributable to a large decrease in Km at the lower pH value. The results indicate that the enzyme exhibits high catalytic efficiency toward substrates such as pyrophosphate and acidic phosphotyrosine-containing peptides, particularly at low pH values typical of the bone resorptive space. The implications of the results for the physiological function of the enzyme are discussed.

Interstitial lung disease related to dermatomyositis. Comparative study with patients without lung involvement.

OBJECTIVE: To compare clinical and histopathological data and outcome of patients with dermatomyositis (DM) with and without interstitial lung disease (ILD). METHODS: Patients diagnosed with definite DM were prospectively evaluated. Clinical and analytical data were recorded and muscle biopsies were performed. In patients with respiratory symptoms an extensive pulmonary evaluation was done. RESULTS: 104 patients were diagnosed with idiopathic inflammatory myopathy, 63 with DM. Eight of the patients with DM (13%) also had associated ILD. Arthralgia and fever were more frequently seen in the ILD group and there was no associated malignant condition. Either atypical or nonspecific cutaneous lesions were more frequently seen in ILD patients. Anti Jo-1 antibodies were positive in 75% of the patients with ILD and in 3% of patients with DM without ILD (p < 0.001). Bronchoalveolar lavage measured for cell count showed an increased lymphocyte count in 3/5 cases in which this data was recorded. Lung biopsies showed interstitial pneumonitis in 2 cases and desquamative interstitial pneumonitis in one. All patients achieved complete remission of muscular involvement. With respect to lung disease, 4/8 obtained complete remission, and the other 4 showed partial improvement. No significant statistical differences in terms of survival were found between the 2 groups. CONCLUSION: ILD associated with DM represents a subgroup of DM with clinical and biological differences. However, such patients do not have poorer prognosis than patients without ILD if they are managed aggressively with immunosuppressive drugs.

[Computer-based measurements of bladder cancer urothelial cells by high-resolution microscopic-cytophotometric system (author's transl)]. / Rechnergesteuerte Mikroskopzytophotometrische Messungen an Urothelzellen von Blasenkarzinomen.

Examination of exfoliated urothelial cells present in the urine has been shown to be diagnostic by many researchers, but cytology is not yet widely accepted for routine diagnostic purposes. Cytology is highly efficient in the primary diagnosis of high grade transitional carcinoma (grade II-III) but of limited value in the diagnosis of benign papilloma and low grade tumors. The sensitivity of cytology would be increased by improving the techniques of collecting cells out of urine, using highly sensitive staining techniques and by objective cytologic measuring methods. Using a computer-based cytophotometric microscope, the cytologic analysis of 26 patients with bladder tumors are represented. There is evidence that a computerized measuring system is able to detect bladder tumors with a high accuracy.