Pretransplant donor-specific interferon-gamma ELISPOT assay predicts acute rejection episodes in renal transplant recipients.

Interferon (IFN)-gamma enzyme-linked immunosorbent spot (ELISPOT) assay is a powerful tool for measuring the frequency of alloantigen-specific T cells, reflecting cellular immunity. We correlated the pretransplant frequencies of donor-specific and third-party-specific IFN-gamma ELISPOT tests, with the posttransplant outcomes of 45 recipients of living donor renal transplantations. The mean frequency of pretransplant donor-specific ELISPOT was significantly greater among patients with acute rejection episodes (ARE) than those without ARE (18.0 [12 to 50] versus 8.8 [5 to 30.4]) spots per 200,000 peripheral blood lymphocytes (PBLs; P=.024). A cutoff level of 12 spots per 200,000 PBLs on the donor-specific ELISPOT identified an ARE-positive patient with a sensitivity of 81.8% and a specificity of 64.7%. The recipients with pretransplant donor-specific ELISPOT+showed higher serum creatinine levels and lower glomerular filtration rate (GFR) at 6 posttransplant months (P<.05). Although the pretransplant third-party-specific ELISPOT results correlated with the donor-specific ELISPOT results (r=.783; P<.001), there was no significant difference in the third-party ELISPOT results between the ARE-positive and ARE-negative recipients. In conclusion, an analysis of pretransplant donor-specific IFN-gamma ELISPOT may identify the posttransplant risk of developing ARE and displaying decreased GFR at 6 months.

Identification of two new alleles in a single Korean individual, HLA-B*1568 and HLA-DRB1*1208.

We have identified a new HLA-B*15 allele and a new HLA-DRB1*12 allele, named B*1568 and DRB1*1208, respectively. The alleles were identified using a combination of sequence specific primers, reverse line sequence specific oligonucleotide probing and sequence-based typing. Both alleles were identified in a single individual of Korean origin. HLA-B*1568 appears to be an HLA-B*4801/B*1507 hybrid combining the exon 2 sequence of B*4801 and the exon 3 and 4 sequences of B*1507. Exon 2 of DRB1*1208 was most similar to DRB1*1201 or 1206, with a single mismatch at nucleotide position 165 (A to C). At the protein level, this substitution results in a phenylalanine substitution at position 26 that creates an identical amino acid sequence to DRB3*0202 between amino acid positions 17 and 36.

Pharmacological preconditioning with low-dose cyclosporine or FK506 reduces subsequent ischemia/reperfusion injury in rat kidney.

BACKGROUND: Ischemia/reperfusion (I/R) injury in the early posttransplant period is closely associated with delayed recovery of graft function, increased acute rejection, and late allograft dysfunction. Pharmacological preconditioning with low-dose cyclosporine (CsA) or FK506 was performed to induce ischemic tolerance in rat kidney with I/R injury. METHODS: Low-dose CsA (3 mg/kg, administered i.v.) or FK506 (0.3 mg/kg i.v.) were used to induce ischemic tolerance in Sprague-Dawley rats, and the induction of heat shock protein (hsp) 70 by CsA or FK506 was evaluated overtime. Rats were pretreated with CsA or FK506 6 hr before I/R injury when hsp70 was maximally expressed, and were killed 24 hr later. The effect of pharmacological preconditioning on subsequent I/R injury was evaluated in terms of renal function, histopathology score, assays for apoptosis (DNA fragmentation analysis, TUNEL staining, expressions of pro-apoptotic genes, and caspase activity), and the expression of inflammatory cytokine genes (interleukin-1 and tumor necrosis factor-alpha). RESULTS: Preconditioning with low-dose CsA or FK506 significantly improved renal function and renal histology, compared to rats with I/R injury. Apoptotic cell death (typical DNA laddering and increased TUNEL-positive cells) in rat kidneys with I/R injury, was decreased by pretreatment with low-dose CsA or FK506. Increased expression of pro-apoptotic genes (Fas, Fas-ligand, caspase 1 and 3) and activated caspases in ischemic rat kidneys were decreased after CsA or FK506 pretreatment. CONCLUSIONS: Pretreatment with low-dose CsA or FK506 prevents subsequent I/R injury, and this effect may be related to the induction of hsp70. Pretreatment of renal donors with low-dose CsA or FK506 may result in an improvement in immediate posttransplant function.

Influence of the renin-angiotensin system on epidermal growth factor expression in normal and cyclosporine-treated rat kidney.

BACKGROUND: Epidermal growth factor (EGF) plays an important role in renal tubular regeneration after ischemic injury in kidney. The present study reports the association between the renin-angiotensin system (RAS) and EGF, and the effect of angiotensin II blockade with losartan (LSRT) on EGF expression in an experimental model of chronic cyclosporine (CsA) nephrotoxicity in rats. METHODS: Two separate experiments were performed. In the first experiment, rats on the normal-salt diet (NSD; 0.3%) or low-salt diet (LSD; 0.05%) were treated with or without LSRT for four weeks. In the second experiment, rats on the NSD or LSD were given vehicle (VH group, olive oil, 1 mg/kg per day) or CsA (15 mg/kg per day) or CsA (15 mg/kg per day) plus LSRT (100 mg/L per day). Renal function, histopathology, TUNEL staining, plasma renin activity (PRA), and the expression of renin and EGF were studied. RESULTS: Normal rats on the LSD showed significantly increased EGF expression (cortex, 2.6-fold; medulla, 1.7-fold) and significantly decreased EGF expression with the LSRT treatment compared with the rats treated with the NSD (cortex, 74.8 vs. 10%; medulla, 22.5 vs. 5%). In contrast, the CsA-treated rats on the LSD had a significantly lower EGF expression (cortex, 98 vs. 53%; medulla, 94 vs. 14%); however, concomitant administration of LSRT increased the EGF expression (cortex, 91- vs. 3.8-fold; medulla, 19- vs. 2.4-fold) compared with the rats on the NSD. In the normal and CsA-treated LSD rats, EGF expression was well correlated with PRA. In addition, EGF expression was well correlated with the interstitial fibrosis score (r = 0.664, P < 0.01) or number of TUNEL-positive cells (r = 0.822, P < 0.01) in CsA-treated LSD rats. CONCLUSIONS: These results suggest that angiotensin II blockade with LSRT decreases EGF expression in normal rats on the LSD, but it protects EGF expression in CsA-induced nephrotoxicity. This finding provides a new perspective on the renoprotection of angiotensin II blockade in chronic CsA nephrotoxicity.

Sonographic evaluation of gallbladder-wall thickening in hemorrhagic fever with renal syndrome: prediction of disease severity.

PURPOSE: Gallbladder-wall thickening (GBWT) frequently occurs in patients with hemorrhagic fever with renal syndrome (HFRS), an acute infectious disease caused by hantaviruses. HFRS is manifested by fever, hemorrhage, renal failure, and in many cases gastrointestinal symptoms, such as abdominal pain and tenderness. The clinical significance of GBWT in HFRS has not been reported. The purpose of this study was to investigate the incidence of GBWT and the relationship between GBWT and the severity of HFRS. METHODS: We retrospectively reviewed the medical records and sonograms of 68 patients with HFRS (47 males and 21 females, with an age range of 10-76 years) who underwent abdominal sonography in the acute stage of the disease. We measured the gallbladder-wall thickness on the sonograms and reviewed other sonographic and radiographic findings. Clinical factors that reflect the severity of HFRS were compared between the patients with GBWT (defined as thickness of 4 mm or more) and those without GBWT. RESULTS: Of the 68 patients, 29 (43%) had GBWT, which was even and diffuse in all cases. The patients with GBWT had a significantly lower mean platelet count and serum albumin level and significantly higher serum aspartate aminotransferase and serum lactate dehydrogenase levels than did the patients without GBWT. In addition, the incidence of renal failure requiring hemodialysis and the incidences of ascites and pleural effusion were higher in the patients with GBWT than in those without GBWT. Five patients died of HFRS; all 5 had GBWT (p = 0.011 for comparison with patients without GBWT). CONCLUSIONS: Our results suggest that the sonographic measurement of gallbladder-wall thickness during the acute stage of HFRS is useful for determining the severity of HFRS.

Thyroxine treatment induces upregulation of renin-angiotensin-aldosterone system due to decreasing effective plasma volume in patients with primary myxoedema.

BACKGROUND: In experimental animals and humans, hypothyroidism is associated with fluid retention and generalized oedema, increased antidiuretic hormone (ADH), decreased atrial natriuretic hormone (ANH), and decreased renin-angiotensin-aldosterone system (RAAS), which subsequently can be corrected by thyroid hormone replacement. The purpose of this study was to determine the effect of thyroxine therapy on RAAS and neurohormones affecting water and electrolyte metabolism and the reason for these changes in patients with primary myxoedema. METHODS: We measured changes in the plasma renin activity (PRA), serum aldosterone (Aldo), ADH, ANH levels, serum and 24 h urinary electrolytes and osmolalities, and cardiac function in 22 female patients with primary myxoedema before and after correction of hypothyroidism. We also evaluated age-, sex-, and BMI-matched 15 healthy control subjects (Cont). RESULTS: It took an average of 4.3 months (range, 3-9 months) to normalize thyroid function. The mean reductions of body weight and estimated plasma volume were 1.8+/-1.0 kg (P=0.002) and 8.5% (P<0.001), respectively. In addition, serum Na+ and osmolality and the haematocrit were significantly elevated after correction of hypothyroidism (P<0.01 and P<0.001, respectively). Increased F(E)Na and C(OSM) (P<0.05) levels in patients with hypothyroidism (Ho) compared with those in Cont did not change after thyroxine therapy (Eu). However, C(H(2)O), U(E)K, F(E)K, and TTKG levels as well as creatinine clearance (Ccr) were markedly increased in Eu compared with Ho and Cont (P<0.01, respectively). Increased plasma ADH concentration and decreased plasma ANH concentration were normalized compared to Cont after thyroxine therapy (P<0.001 and P<0.01, respectively). Low PRA and serum Aldo concentration in Ho were significantly increased in Eu (P<0.001 and P<0.01, respectively). In addition, increased left ventricular mass index and decreased cardiac output in Ho were normalized compared to Cont after thyroxine therapy (P<0.01, respectively) CONCLUSIONS: These findings suggest that the exaggerated upregulation of RAAS after correction of hypothyroidism in patients with primary myxoedema is associated with an increase in Ccr and a decrease in plasma volume resulting from water diuresis, natriuresis, osmotic diuresis and inappropriate changes in plasma ADH and ANH levels. The improved renal function coincided with an amelioration of cardiac function. These changes seem to be an adaptive response for preventing excessive plasma volume and weight loss after thyroxine therapy.

Serum cystatin C is an independent predictor of total homocysteine levels in stable Korean renal transplant recipients with normal serum creatinine.

OBJECTIVES: To examine the determinants of fasting plasma total homocysteine (tHcy) levels such as cystatin C, serum creatinine (SCr), estimated glomerular filtration rate (GFR) from Cockroft-Gault equation, albumin, plasma folate, vitamin B12, and pyridoxal-5'-phosphate (PLP) among Korean renal transplant recipients (RTR) with normal SCr levels (< or =1.4 mg/dL). DESIGN: Cross-sectional study. SETTING: Nephrology and Transplant Service, Catholic University Kangnam St. Mary's Hospital, Seoul, Korea. PARTICIPANTS: Fifty-one chronic stable Korean RTR with normal SCr levels (< or =1.4 mg/dL) 6 months or more following transplantation. MEASURES: Medical record review, anthropometric measurements, and overnight (10 to 14 hours) fasting blood samples for measurement of plasma tHcy, folate, vitamin B12, PLP, SCr, albumin, and cystatin C. RESULTS: General linear regression model including age, gender, vitamin status, and measurements of renal function showed that cystatin C and folate were independent predictors of tHcy levels. The partial regression coefficient for folate was -0.444 (P <.01) and for cystatin C, it was +0.334 (P <.05). SCr, estimated GFR, vitamin B12, PLP, age, and gender were not independent predictors of tHcy levels in this model. CONCLUSION: Both cystatin C and folate status were major independent determinants of fasting tHcy levels in the subgroup of Korean RTR with normal SCr.

Access blood flow as a predictor of early failures of native arteriovenous fistulas in hemodialysis patients.

Blood flow imaging using color doppler has proven effective in predicting graft failures in hemodialysis patients, but its effect on native arteriovenous fistulas (AVF) is not well known. This study was performed to investigate whether measurements of the access blood flow can be used as predictors of an early failure of a native AVF in hemodialysis patients. Fifty-three consecutive patients who received native AVF operations were included in this study. Access blood flow was measured at 1 week after operations, and AVF function was followed for 4 months. During the follow-up, access failures developed in 10 patients at 9.8 +/- 3.5 weeks. AVF blood flow was significantly lower in the failure group (n = 10) than in the patent group (n = 43) (450 +/- 214 vs. 814 +/- 348 ml/min, p = 0.003). The incidence of access failures was higher in the patients with a flow <350 ml/min (n = 9) compared to the patients with a flow >350 ml/min (n = 44) (55.5 vs. 11.3%, p = 0.008). The diameters of veins were significantly smaller in the failure group than in the patent group (3.5 +/- 0.5 vs. 4.1 +/- 0.7 mm, p = 0.018). The incidence of diabetes mellitus was higher in the failure group than in the patent group (90 vs. 51%, p = 0.025). However, age, sex, duration from an operation to first cannulation, and different AVF sites did not make a significant difference between the two groups. Our data suggest that access blood flow measurements using color doppler ultrasound during early postoperative periods are useful parameters in predicting an early failure of a native AVF in hemodialysis patients.

Successful treatment of massive lower gastrointestinal bleeding caused by mixed infection of cytomegalovirus and mucormycosis in a renal transplant recipient.

We describe a case of lower gastrointestinal bleeding due to mixed infection of cytomegalovirus (CMV) and mucormycosis in a renal transplant recipient. A 33-year-old male received renal transplantation and his clinical course was uneventful. On the 18th postoperative day, acute rejection was developed and this was treated with high-dose methylprednisolone and OKT3. During antirejection treatment, sudden onset massive hematochezia was developed. Emergency colonofibroscopy revealed multiple colonic ulcers and pathologic findings were consistent with mucormycosis and CMV infection. The patient was successfully treated with amphotericin B (1.0-1.5 mg/kg) and ganciclovir (62.5-125 mg/day) for 5 weeks. To our knowledge, this is the first report showing coexistence of mucormycosis and CMV in the colon ulcer base. This finding suggests that CMV infection may trigger fungal infection in the pathogenesis of colonic ulcer.

Preconditioning with sodium arsenite inhibits apoptotic cell death in rat kidney with ischemia/reperfusion or cyclosporine-induced Injuries. The possible role of heat-shock protein 70 as a mediator of ischemic tolerance.

This study was performed to evaluate the effect of heat-shock protein (HSP)70 induction with sodium arsenite (SA) on ischemia/reperfusion (I/R) or cyclosporin A (CsA)-induced injuries in rat kidney. Rats were classified into five groups (sham, I/R, SA+I/R, I/R+CsA and SA+I/R+CsA groups) according to both the status of SA pretreatment and treatment with CsA. SA (6 mg/kg, i.v.) pretreatment was accomplished 12 h before I/R injury, and CsA (20 mg/kg, s.c.) was given subsequent to I/R injury. The effect of SA pretreatment on I/R injury was evaluated using measurements of renal function, the histopathology score, and assays for apoptosis (DNA fragmentation analysis, TUNEL staining, mRNA expressions of the pro-apoptotic genes and caspase activities). In addition, mitochondrial morphology was examined by electron microscopy. Induction of HSP70 with SA improved both renal function and the histopathology score as compared to the group without HSP70 induction. The assays for apoptosis revealed that SA pretreatment decreased the DNA laddering pattern, TUNEL-positive cells, mRNAs expression of pro-apoptotic genes and caspase activities as compared with the group without SA pretreatment. In addition, the mitochondrial morphology was well preserved in the groups with SA pretreatment. In conclusion, SA pretreatment prevents subsequent I/R or CsA-induced injuries in the rat kidney, and this renoprotective effect appears to be mediated by induction of HSP70.

Clinical significance of anti-endothelial cell antibody in renal transplant recipients.

In order to evaluate the role of anti-endothelial cell antibody (AECA) in acute rejection in renal transplantation, serum AECA IgG titers were measured in 68 healthy controls, 111 chronic hemodialysis (HD) patients and 58 first renal transplant recipients. The AECA titer in hemodialysis patients was higher than in healthy controls (13.9 +/- 5.0 vs. 4.8 +/- 2.3 U/mL, p < 0.01). In transplant recipients, AECA titers were not affected by dialysis mode (HD vs. CAPD vs. non-dialysis; 9.6 +/- 7.6 vs. 7.9 +/- 3.9 vs. 11.9 +/- 3.1 U/mL, p > 0.05). After renal transplantation, AECA titer was decreased significantly (vs. 4.7 +/- 3.6 U/mL. p < 0.01). The serum AECA IgG titers increased significantly in recipients with acute rejection (6.9 +/- 3.1 vs. 13.5 +/- 9.9 U/mL, p < 0.01), but decreased to 5.6 +/- 3.0 U/mL (p < 0.01) after formal rejection therapy. In the recipients with acute rejection (n = 27), the pre-renal transplant AECA titer was higher than in that without acute rejection (14.0 +/- 8.6 vs. 7.7 +/- 3.8 U/mL, p < 0.01). The results of this study lead us to conclude that pre- and post-renal transplant AECA titer might be a useful predictor for acute rejection and useful for monitoring acute rejection in renal transplant recipients.

Juxtaglomerular cell tumor of the kidney: a case report.

We report a case of renin-secreting juxtaglomerular cell tumor which developed in a hypertensive 47-yr-old Korean man. Presumptive clinical diagnosis was made before surgery based on the high level of plasma renin and the radiologic evidence of renal mass. Grossly, a round, bulging, well-encapsulated mass of 3 x 3 cm was located in the mid-portion of the right kidney. On microscopic examination, the tumor was composed of ovoid to polyhedral cells with bland nuclei, indistinct nucleoli and light eosinophilic cytoplasm. The immunostaining for renin showed strong positivity in the cytoplasm of tumor cells. The characteristic rhomboid shaped renin protogranules were observed in ultrastructural analysis.