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Biomedical subjects

H Kreis

Publications and source records attributed to H Kreis.

At least 73 records · Page 4Linked to original sources

Osteonecrosis of the hip in renal transplant recipients. Changes in functional status and magnetic resonance imaging findings over three years in three hundred five patients.

OBJECTIVE: to conduct a retrospective study of the appearance and course of magnetic resonance imaging abnormalities in avascular osteonecrosis of the femoral head in renal transplant recipients and of potential relations between these abnormalities and the functional outcome. PATIENTS AND METHODS: among 305 renal transplant recipients, patients with pain in the hips or knees underwent radiographs and magnetic resonance imaging studies of the hips and, if appropriate, of the knees. The mean time interval between these studies and transplantation was 8.9 months. The outcome was evaluated based on the Lequesne index and findings from a repeat magnetic resonance imaging study after a mean follow-up of 33 months since transplantation. The criteria developed by Mitchell et al. were used to diagnose osteonecrosis on magnetic resonance images. The size of the necrotic area was estimated using the tracing paper method as < 25%, 25-50%, > 50% of the surface of the femoral head. Eleven patients were treated by elimination of weight-bearing and conservative treatments and 15 underwent core decompression (radiographic stage I or II). RESULTS: Fourteen patients (4.5%) developed osteonecrosis of the femoral head, which was bilateral in 12 patients and unilateral in two: thus, the total number of hips with osteonecrosis was 26. The first magnetic resonance imaging study disclosed a crescent-shaped area of low signal intensity in 25 cases, most of which were mild in severity as assessed on radiographs (Arlet and Ficat stage I or II). Extensive necrosis was found in most cases at the first evaluation (> 25% in 15 cases and > 50% in eight). The surface of the necrotic area (as assessed irrespective of the treatment used) remained unchanged in 20 cases and decreased in six. In half the cases the hyperintense signal from the sequestrum converted to a hypointense signal after a mean follow-up of 39 years. A poor functional outcome (Lequesne's index > 7 or total hip arthroplasty) was seen in 61.5% of cases, irrespective of the treatment used. CONCLUSION: Avascular osteonecrosis of the femoral head precipitated by corticosteroid therapy in renal transplant recipients occurred in 4.5% of patients immediately involved a large segment of the epiphysis, and usually remained stable over time, although a decrease in the size of the lesion was seen in a few cases. Overall, the functional prognosis was poor, with a Lequesne's index greater than 7 or total hip arthroplasty in two thirds of cases after three years' follow-up. The incidence of avascular osteonecrosis of the hip in renal transplant recipients has decreased since 1980, when cyclosporin was introduced and doses of corticosteroids used to treat rejection episodes were diminished.

Adult↗

Monitoring of azathioprine-induced immunosuppression with thiopurine methyltransferase activity in kidney transplant recipients.

Thiopurine methyltransferase (TPMT), one of the enzymes involved in azathioprine metabolism, exhibits a wide range of activity in the normal population. We prospectively evaluated the monitoring of erythrocyte TPMT activity (using a radiochemical method) in kidney transplant recipients with regard to the efficacy of azathioprine. Three patterns in TPMT activity variation were observed. In group 1 patients, TPMT activity rose as early as 8 days after transplantation and steadily until month 3. In group 3 patients, TPMT activity remained unchanged. In group 2 patients, TPMT activity rose at month 1 after transplantation. Interestingly, the incidence of acute rejection was significantly (P < 0.01) different among the 3 groups, with the lowest incidence in group 1 and the highest in group 3. We hypothesized that TPMT activity increase was induced by azathioprine in the patients with the lowest incidence of acute rejection. The inducibility of TPMT activity would then appear to be an interesting marker of azathioprine-induced immunosuppression.

Azathioprine↗

[Homozygote deficiency of thiopurine methyltransferase. A contraindication to the use of azathioprine in kidney transplantation].

Azathioprine-induced myelosuppression is the most important side effect observed in kidney transplantation. We report a case of severe neutropenia after kidney transplantation due to a thiopurine methyltransferase deficiency. This cause of azathioprine-induced myelotoxicity is rare, but its infectious consequences may be severe. Thiopurine methyltransferase deficiency must therefore be suspected when early and severe leukopenia occurs during azathioprine therapy. Erythrocyte thiopurine methyltransferase activity measurement confirms the diagnosis. Azathioprine and 6-mercaptopurine must afterwards be definitively avoided.

Azathioprine↗

In vivo soluble tumor necrosis factor receptor release in OKT3-treated patients. Differential regulation of TNF-sR55 and TNF-sR75.

Administration of monoclonal antibodies to CD3 triggers acute and massive release of several cytokines, including tumor necrosis factor alpha (TNF-alpha), essentially T cell-derived. This cytokine release is responsible for the spontaneously reversible acute clinical syndrome observed in most OKT3-treated patients. We found that the first OKT3 injection in human renal allograft recipients led to the release in significant amounts of soluble TNF receptors (TNF-sR55 and TNF-sR75) that are considered main natural inhibitors of TNF bioactivity. As for OKT3-induced TNF-alpha, peak TNF-sR levels were observed 1 hr postinjection, and this release was limited to the first monoclonal antibody injection. A distinct regulation of OKT3-mediated release of TNF-sR75 and TNF-sR55 was observed, since (1) in clear contrast with OKT3-mediated TNF-sR75 induction, TNF-sR55 release was completely blocked by a high dose of corticosteroids prior to OKT3 injection and (2) secretion of TNF-sR75 but not TNF-sR55 correlated with immunoreactive TNF-alpha release. In hemodialyzed patients prior to transplantation and OKT3 treatment, a condition characterized by chronic TNF-alpha release, TNF-sR efficiently block TNF bioactivity. In contrast, the system is overwhelmed by the massive acute TNF-alpha release that follows the first OKT3 injection: in such a condition TNF-sR looses its capacity to counteract TNF bioactivity.

Adrenal Cortex Hormones↗

Outbreak of Pneumocystis carinii pneumonia in a renal transplant unit.

The charts for seven renal transplant recipients who developed Pneumocystis carinii pneumonia were reviewed. They included six men and one woman transplanted a mean of 150 days before the diagnosis of this infection. Six presented at least one episode of acute graft rejection. Cytomegalovirus pneumonia was diagnosed in six of the patients. All patients were treated with cotrimoxazole. Global mortality was 43%. In additional to the classic hypothesis of latent Pneumocystis carinii reactivation in immunocompromised hosts, this and previous reports of outbreaks strongly suggest either a person-to-person transmission or acquisition from the environment. Molecular typing of isolates could be of value in identifying the source of such outbreaks. Chemoprophylaxis should be more systematically administered to renal transplant patients, co-trimoxazole being the drug of choice.

AIDS-Related Opportunistic Infections↗

The changing relative prevalence of hepatitis C virus genotypes: evidence in hemodialyzed patients and kidney recipients.

BACKGROUND/AIMS: Hepatitis C virus (HCV) infection by the genotype 1b is significantly associated with a lower rate of response to interferon alfa and with severe liver disease (cirrhosis and hepatocellular carcinoma). This may reflect different intrinsic properties of this genotype 1b and/or chronological differences in the epidemiology of HCV genotypes. To address the issue of variations in genotypes prevalence, we studied in the present report the HCV genotypes of 60 hemodialyzed and kidney recipients according to the date of hemodialysis. METHODS: Anti-HCV antibodies were tested by a second-generation assay (enzyme-linked immunosorbent assay 2 and recombinant immunoblot assay 2). HCV RNA was detected by reverse-transcription polymerase chain reaction. Genotyping was performed by hybridization of type-specific probes to the amplified product from the 5' untranslated region. RESULTS: Genotype 1b accounted for more than two thirds of HCV infection in patients who underwent dialysis before 1977 but less than one third in those hemodialyzed after 1985. In contrast, other genotypes (3a, 4a, 5a) appeared in the 1980s. CONCLUSIONS: These data, obtained in an homogenous group of patients, show a changing pattern of HCV genotype prevalence over time and should be considered when discussing the potential clinical implications of HCV genetic variability.

Female↗

Dialysis arthropathy: outcome after renal transplantation.

PURPOSE: Patients treated by long-term maintenance hemodialysis frequently develop a form of chronic arthropathy that is strongly associated with beta 2-microglobulin amyloid deposition and related, at least in part, to beta 2-microglobulin retention. Successful renal transplantation is followed by a rapid fall in serum beta 2-microglobulin levels and might allow dissolution of amyloid deposits. The purpose of this work was to investigate the effects of renal transplantation on dialysis arthropathy. PATIENTS AND METHODS: Fourteen renal transplant recipients were selected on the basis of previous hemodialysis treatment for at least 10 years (mean 16) and a history of chronic joint pain prior to transplantation. They all received 10 to 17.5 mg/d of prednisone. Posttransplant rheumatologic manifestations were studied prospectively and compared to pretransplant rheumatologic manifestations recorded in medical charts and reported during patient interviews. Pretransplant and posttransplant articular roentgenograms were separately analyzed by three observers who were blinded to timing of the films. Beta 2-microglobulin amyloid was identified by Congo red staining and immunohistology. RESULTS: After a mean posttransplant interval of 54 months (range 12 to 121), the articular condition was improved in 10 patients, unchanged in 1, and worsened in 3, according to patients' assessments. The number of painful joints decreased significantly (P < 0.05) as compared to the pretransplant period. However, the number and size of subchondral bone erosions remained unchanged, destructive arthropathies generally worsened, and articular beta 2-microglobulin amyloid deposits were identified in 2 patients, 2 and 10 years after renal transplantation, respectively. CONCLUSION: Renal transplantation appeared to arrest progression of beta 2-microglobulin amyloid in dialysis patients, but it neither led to dissolution of deposits nor prevented progression of destructive arthropathies. Most articular symptoms were improved, probably as a result of corticosteroid therapy.

Adult↗