Posterior Reversible Encephalopathy Syndrome during Recovery from Acute Kidney Injury after Hepatitis A Infection

The patient was a 25-year-old healthy male who experienced fever, chills, and abdominal pain for 5 days prior to the hospital visit. He was diagnosed with acute hepatitis A, and at admission he presented with anuric acute kidney injury and hepatic encephalopathy. He received continuous renal replacement therapy followed by intermittent regular hemodialysis. His urine output increased to 1,610 ml/day after 31 days. On day 32, he suddenly developed a headache and visual disturbance and experienced three short convulsions, which were followed by postictal confusion and high fever. T2 and FLAIR MRI images of the brain revealed hyperintense signal alterations in bilateral subcortical regions of the temporoparietal and occipital lobes, consistent with posterior reversible encephalopathy syndrome. His mental status was fully recovered after 7 h of conservative treatment, including antihypertensive therapy. On hospital day 56, the renal function of the patient had recovered, and he was discharged without neurologic sequelae.

Comparison between thymoglobulin and ATGAM as an induction agent in adult kidney transplantation: a single-center experience

OBJECTIVE

The best antithymocyte globulin (ATG) preparation for induction suppression in kidney transplant recipients is still not clear. The aim of this study was to identify short- and long-term outcomes in kidney transplant recipients who received thymoglobulin or ATGAM as an induction agent.

METHODS

We retrospectively reviewed patients who underwent kidney transplantation from 1996 to 2010. Recipients were classified according to the ATG preparation.

RESULTS

One hundred fifty-two patients (64.4%) received thymoglobulin and 84 (35.6%) received ATGAM. The occurrence of delayed graft function in patients receiving thymoglobulin was higher than in patients receiving ATGAM (P = .005), but serum creatinine levels and acute rejection after kidney transplantation were not different between the two groups. The death-censored graft survival curve in thymoglobulin recipients was higher than in ATGAM recipients (P = .027). Bacterial infection was a predisposing factor for graft survival (P = .008).

CONCLUSION

The efficacy of thymoglobulin induction is generally better than that of ATGAM induction, and prevention of bacterial infections was just as important as the use of ATG because bacterial infection was an important risk factor for graft failure.

[Clinicopathologic features of cases with negative pathologic results after endoscopic submucosal dissection]

BACKGROUND/AIMS

Endoscopic submucosal dissection (ESD) is accepted as a standard treatment of early gastric cancer (EGC) and gastric adenoma. Occasionally, tumorous lesion is not found and pathologic discrepancies can occur after ESD. The aim of this study was to analyze the factors affecting the negative pathologic results after ESD.

METHODS

We retrospectively reviewed the data from all patients with gastric neoplasm (276 EGC and 516 gastric adenomas) who were treated with ESD during past 3 years and enrolled the patients who had negative pathologic results.

RESULTS

Out of 792 patients treated with ESD, 27 patients (3.4%) were eligible for inclusion. Among the 27 patients, factors affecting the negative pathologic results were, most commonly, the focal lesion (n=13, 48.2%) which was small enough to be removed completely during pre-ESD biopsy, followed by pathologic discrepancies (n=11, 40.7%) between pathologists and lastly the operator factor (n=3, 11.1%) dissecting incorrect lesions. Of the focal lesions, the initial pathologic diagnoses were adenocarcinoma in 11 cases (84.6%). In cases with pathologic discrepancies, all the pretreatment diagnoses were adenoma with low grade dysplasia. In cases caused by operator factors, intestinal metaplasia was accompanied by elevated adenoma in all cases.

CONCLUSIONS

To decrease negative pathologic results after ESD, an endoscopist should perform ESD after sufficient communication with pathologists, especially for adenoma with low grade dysplasia, and choose correct lesion, especially located at the antrum and associated with intestinal metaplasia. The possibility of total removal of small lesions even by forcep biopsy should be considered.

Comparison on the Efficacy of Disinfectants Used in Automated Endoscope Reprocessors: PHMB-DBAC versus Orthophthalaldehyde

BACKGROUND/AIMS

Since endoscopes are reusable apparatus classified as semicritical item, thorough reprocessing to achieve high-level disinfection is of utmost importance to prevent spread of infection. To improve disinfection efficacy and safety, disinfectants and endoscope reprocessors are continuously evolving. This study aimed to compare the efficacy of the combination of polyhexamethylenebiguanide hydrochloride-alkyldimethylbenzylammonium chloride (PHMB-DBAC) and orthophthalaldehyde (OPA) used respectively in ultrasonographic cleaning incorporated automated endoscope reprocessors: COOLENDO (APEX Korea) or OER-A (Olympus Optical).

METHODS

A total of 86 flexible upper endoscopes were randomly reprocessed with either COOLENDO/PHMB-DBAC or OER-A/OPA. Culture samplings were done at two sites (endoscope tip and working channel) which were later incubated on blood agar plate. Bacterial colonies were counted and identified.

RESULTS

The culture-positive rate at the endoscope tip and working channel was 0% and 2.33% for COOLENDO/PHMB-DBAC and 4.65% and 0% for OER-A/OPA. Staphylococcus hominis was cultured from one endoscope reprocessed with COOLENDO/PHMB-DBAC and Pseudomonas putida was isolated from two endoscopes reprocessed with OER-A/OPA.

CONCLUSIONS

The reprocessing efficacy of COOLENDO/PHMB-DBAC was non-inferior to that of OER-A/OPA (p=0.032; confidence interval, -0.042 to 0.042). During the study period, significant side effect of PHMB-DBAC was not observed.

Post-operative acute kidney injury in patients with renal cell carcinoma is a potent risk factor for new-onset chronic kidney disease after radical nephrectomy

BACKGROUND

Radical nephrectomy is a significant risk factor for chronic kidney disease (CKD). There are few reports on the renal outcome of acute kidney injury (AKI) after radical nephrectomy. The aim of this study was to determine the incidence of AKI and whether post-operative AKI is associated with new-onset CKD after radical nephrectomy for renal cell cancer (RCC).

METHODS

We conducted a retrospective study of 519 adult patients (>40 years old) with normal renal function who underwent unilateral radical nephrectomy for a solitary renal cortical tumour and were pathologically diagnosed with RCC between January 2000 and February 2007. Post-operative AKI was classed using risk, injury, failure, loss and end-stage kidney disease (RIFLE) criteria. CKD was defined as a decrease in estimated glomerular filtration rate (GFR) to <60 mL/min/1.73 m(2).

RESULTS

According to the RIFLE criteria, 165 of 175 patients fell into the AKI risk category, 8 patients fell into the AKI injury category and 2 patients fell into the AKI failure category. Multivariate analysis revealed that older age [odds ratio (OR) 1.02, 95% confidence interval (CI) 1.00-1.05], male gender (OR 3.13, 95% CI 1.91-5.12), higher body mass index (OR 1.08, 95% CI 1.01-1.15), smaller RCC size (OR 0.87, 95% CI 0.81-0.93) and higher preoperative GFR (OR 1.04, 95% CI 1.03-1.06) were independent risk factors for post-operative AKI. CKD was more prevalent in the AKI risk group than in patients without AKI 1 year after surgery (54.7% versus 43.9%, respectively; P = 0.006) and 3 years after surgery (50% versus 32%, respectively; P = 0.003). Patients who experienced post-operative AKI had a 4.24-fold higher risk of new-onset CKD after multiple adjustments were made to the data (95% CI 2.28-7.89, P < 0.001).

CONCLUSION

AKI after radical nephrectomy in patients with RCC is a potent risk factor for new-onset CKD. Prevention of post-operative AKI is essential for reducing the incidence of CKD after nephrectomy.

Improved gastrointestinal symptoms and quality of life after conversion from mycophenolate mofetil to enteric-coated mycophenolate sodium in renal transplant patients receiving tacrolimus

It is reported that a conversion from mycophenolate mofetil (MMF) to enteric-coated mycophenolate sodium (EC-MPS) relieves gastrointestinal (GI) symptom burden and improves health-related quality of life (HRQoL). However, it is unclear whether renal transplant recipients using tacrolimus receive the same benefit from the conversion. In this prospective, multi-center, open-label trial, patients were categorized into two groups by their GI symptom screening. Equimolar EC-MPS (n=175) was prescribed for patients with GI burdens; those with no complaints remained on MMF (n=83). Gastrointestinal Symptom Rating Scale (GSRS) and Gastrointestinal Quality of Life Index (GIQLI) were evaluated at baseline and after one month. Patients and physicians completed Overall Treatment Effect (OTE) at one month. EC-MPS-converted patients had worse GSRS and GIQLI scores at baseline than MMF-continued patients (all P<0.001). Significant improvements in GSRS and GIQLI scores were observed for EC-MPS-converted patients at one month, but MMF-continued patients showed worsened GSRS scores (all P<0.05). OTE scale indicated that EC-MPS patients improved in overall GI symptoms and HRQoL more than MMF patients did (P<0.001). In tacrolimus-treated renal transplant recipients with GI burdens, a conversion from MMF to EC-MPS improves GI-related symptoms and HRQoL.

Predictors of acute kidney injury associated with intravenous colistin treatment

Colistimethate sodium (CMS) was recently re-introduced into clinical practice as a last resort for the treatment of nosocomial infections caused by multiresistant bacteria. This retrospective cohort study was designed to identify predictors of acute kidney injury (AKI) associated with intravenous (i.v.) CMS treatment. From March 2007 to July 2008, 71 adult patients receiving CMS for > or = 72h were enrolled. AKI was defined using Risk, Injury, Failure, Loss and End-stage kidney disease (RIFLE) criteria according to serum creatinine. The median total dose of CMS was 54.3mg/kg (range 27.5-94.5mg/kg). AKI developed in 38 patients (53.5%). Cox regression analysis based of cumulative CMS dose (mg/kg) identified four independent predictors of AKI: male sex [hazard ratio (HR)=3.55, 95% confidence interval (CI), 1.47-8.55]; concomitant use of a calcineurin inhibitor (HR=6.74, 95% CI 2.49-18.24); hypoalbuminaemia (serum albumin level <2.0g/dL) (HR=6.29, 95% CI 2.04-19.39); and hyperbilirubinaemia (total bilirubin level >5mg/dL) (HR=3.53, 95% CI 1.17-10.71). In conclusion, AKI was a common complication of i.v. CMS treatment. Male sex, concomitant use of calcineurin inhibitors, hypoalbuminaemia and hyperbilirubinaemia were independent predictors of AKI. The effect of AKI on patient outcomes was not determined.

Higher mitochondrial DNA copy number is associated with lower prevalence of microalbuminuria

It has been suggested that mitochondrial dysfunction contributes to the initiation and development of atherosclerosis and cardiovascular disease. We examined the association between mitochondrial DNA (mtDNA) copy number and microalbuminuria in a cross-sectional community-based study. We measured peripheral blood mtDNA copy number in 694 adults without chronic kidney disease by a real-time PCR method. The overall prevalence of microalbuminuria (defined as an albumin creatinine ratio of 30 to 299 mg/g) was 4.5%. The prevalence of microalbuminuria decreased progressively from the lower to the upper quartiles of mtDNA copy number (6.9%, 5.7%, 2.9%, and 2.3% in quartiles 1, 2, 3, and 4, respectively, P=0.017 for trend). Multiple logistic regression models showed that the quartile of mtDNA copy number was independently associated with the prevalence of microalbuminuria (P=0.01 for trend). Compared with the lowest quartile, the highest quartile had an odds ratio of 0.22 for microalbuminuria (95% confidence interval, 0.05 to 0.87; P=0.03). Higher mtDNA copy number was associated with the lower prevalence of microalbuminuria in a community-based population.

Minimal proteinuria one year after transplant is a risk factor for graft survival in kidney transplantation

It is generally accepted that one-year post-transplant proteinuria over 0.5 gm per day has a negative impact on renal graft survival. In this study, the effects of minimal proteinuria less than 0.5 g/day were analyzed in 272 renal recipients who had survived for one year with a functioning graft. Recipients were classified by one-year post-transplant proteinuria: no proteinuria group (<0.2 g/day), minimal proteinuria group (0.2-0.5 g/day), and overt proteinuria group (>or=0.5 g/day). Recipients were followed up for 87.1+/-21 months after transplantation and 38 (13.9%) lost their graft during follow-up. Fifteen percent of patients had minimal proteinuria and 7.8% had overt proteinuria. Five-year graft survival in the minimal proteinuria group was 83.0%, and that in the overt proteinuria group was 70%, in contrast to 97.1% in the no proteinuria group (p=0.01 for trend). In a multivariate analysis, the minimal proteinuria group (relative risk [RR], 4.90; 95% confidence interval [CI], 2.09-11.46) and the overt proteinuria group (RR, 8.75; 95% CI, 3.29-23.29) had higher risks of graft failure than the no proteinuria group. Even minimal proteinuria at one year after transplantation was strongly associated with poor graft outcome. Therefore, it appears logical to consider a low level of proteinuria as a risk factor for graft survival in renal recipients.

N-terminal pro-brain natriuretic peptide levels predict left ventricular systolic function in patients with chronic kidney disease

N-terminal pro-brain natriuretic peptide (NT-proBNP) can be a useful marker for left ventricular (LV) dysfunction in patients without kidney disease. This study was conducted to clarify the relationship between NT-proBNP and LV systolic function in patients with decreased renal function. We studied 256 chronic kidney disease (CKD) patients, patients on dialysis were excluded. The median glomerular filtration rate was 24 (13-36) mL/min/1.73 m(2) and the median NT-proBNP was 4,849 (1,310-19,009) pg/mL. The prevalence of LV systolic dysfunction increased from the lower to the upper NT-proBNP quartiles (I, 17%; II, 34%; III, 61%; and IV, 72%; p<0.001 for trend). The NT-proBNP quartile was an independent predictor of LV systolic dysfunction after adjustment for renal function, compared with quartile I: II, odds ratio (OR) 3.99 (95% confidence interval [CI],1.34-11.93); III, OR 11.28 (95% CI, 3.74-33.95); and IV, OR 36.97 (95% CI, 11.47-119.1). Area under the curve and optimum cut points for NT-proBNP to detect LV systolic dysfunction were 0.781 and 2,165 pg/mL in CKD stage 3, 0.812 and 4,740 pg/mL in CKD stage 4, and 0.745 and 15,892 pg/mL in CKD stage 5. The NT-proBNP level was a predictor of LV systolic dysfunction in CKD patients. Optimum cut points should be stratified according to renal function.

Association between changes in N-terminal pro-brain natriuretic peptide levels and changes in left ventricular mass index in stable hemodialysis patients

BACKGROUND/AIMS

Left ventricular (LV) hypertrophy is a powerful predictor of mortality in dialysis patients. Serial measurements of LV mass provide prognostic information. We evaluated the association between changes in biomarkers and changes in LV mass index (LVMI) in hemodialysis (HD) patients.

METHODS

This was a prospective study of 21 stable HD patients with preserved LV ejection fraction (> or =50%). Echocardiography and measurements of N-terminal pro-brain natriuretic peptide (NT-proBNP), brain natriuretic peptide (BNP) and cardiac troponin T were performed on the same day and repeated 6 and 12 months later.

RESULTS

At baseline, the NT-proBNP and BNP levels correlated with LVMI. Percent changes in LVMI were positively associated with those in log-transformed NT-proBNP levels during both the first (baseline vs. month 6, r = 0.78, p < 0.001) and the second 6 months (months 6 vs. 12, r = 0.73, p < 0.001). Among the 3 biomarkers, NT-proBNP was the only one that was related to changes in LVMI by multivariate correlation analysis, including age, sex, blood pressure, predialysis weight and use of angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker.

CONCLUSION

Our results show that changes in LVMI are closely correlated with variation in NT-proBNP levels in HD patients. These data have significant implications for the application of NT-proBNP as a biomarker for assessing changes in LVMI in HD patients.

Metabolic syndrome, C-reactive protein, and chronic kidney disease in nondiabetic, nonhypertensive adults

BACKGROUND

Metabolic syndrome has been suggested as a risk factor for chronic kidney disease (CKD). Inflammation is associated with both metabolic syndrome and CKD. We investigated inter-relationships between C-reactive protein (CRP), metabolic syndrome, and CKD among 9586 subjects without diabetes or hypertension.

METHODS

Metabolic syndrome was defined according to the criteria of the revised Adult Treatment Panel III. CKD was defined as a glomerular filtration rate <60 mL/min/1.73 m(2) or as albuminuria. A CRP cutpoint of 3 mg/L was used to differentiate high and low CRP groups.

RESULTS

Chronic kidney disease was present in 6.2% of subjects without metabolic syndrome and in 13.1% of subjects with the syndrome (P < .001). In a multivariate model, high blood pressure (BP) (odds ratio [OR], 1.55; 95% confidence interval [CI], 1.24-1.95), high fasting glucose (OR, 1.47; 95% CI, 1.19-1.81), abdominal obesity (OR, 1.52; 95% CI, 1.22-1.81), and high CRP (OR, 1.53; 95% CI, 1.18-1.98) were independently associated with prevalent CKD. Compared with low CRP/without metabolic syndrome, the multivariate-adjusted odds for CKD of high CRP/without metabolic syndrome and low CRP/with metabolic syndrome were 1.48 (95% CI, 1.10-2.0) and 1.90 (95% CI, 1.47-2.45), respectively. Subjects with high CRP and metabolic syndrome had a 3.26-fold greater odds of having CKD (95% CI, 2.00-5.31).

CONCLUSIONS

Metabolic syndrome and high CRP were independently associated with increased prevalence of CKD. The odds of CKD increased in the setting of high CRP and metabolic syndrome.

Association of metabolic syndrome with microalbuminuria in non-hypertensive type 2 diabetic patients

BACKGROUND

Several studies have shown that metabolic syndrome contributed to the development of incident chronic kidney disease in the general population. We evaluated the cross-sectional association between metabolic syndrome and microalbuminuria in patients with type 2 diabetes. We excluded patients with hypertension to distinguish the effects of metabolic syndrome from those of hypertension.

METHODS

A total of 642 non-hypertensive patients with type 2 diabetes were recruited. Metabolic syndrome was assessed according to the NCEP Guidelines and Asian-Pacific criteria for abdominal obesity.

RESULTS

Among all patients, 37.2% were diagnosed as having metabolic syndrome, and these patients had a higher prevalence of microalbuminuria than those without metabolic syndrome (19.7 vs. 13.6%, p = 0.044). There was a graded association between metabolic score and the prevalence of microalbuminuria (p = 0.006 for trend). After adjustment for sex, age, smoking status, C-reactive protein, and HbA(1c), patients with metabolic syndrome had increased odds of 1.58 (95% CI 1.01-2.47) for microalbuminuria. An increment in metabolic score was found to increase the risk of microalbuminuria by 1.34-fold (95% CI 1.07-1.66, p = 0.008).

CONCLUSION

This study demonstrated that metabolic syndrome was associated with an increased risk of microalbuminuria in non-hypertensive patients with type 2 diabetes.

Incidence and radio-uptake patterns of femoral head avascular osteonecrosis at 1 year after renal transplantation: a prospective study with planar bone scintigraphy

OBJECTIVES

We prospectively investigated the incidence of femoral head avascular osteonecrosis (AVN) and radio-uptake patterns of femoral heads on bone scintigraphy at 1 year after renal transplantation.

METHODS

A total of 237 subjects (473 femoral heads) were included. A bone scintigraphy was performed at 12 +/- 1.1 months after renal transplantation, and 17 hips were painful at the time of bone scintigraphy. We graded the radioactivity in each femoral head as normal (grade 0), mildly increased (grade I), and definitely increased (grade II). Typical photon defects in the upper lateral femoral heads were evaluated separately. AVN was confirmed with clinical follow-up of more than 1 year and MRI and/or plain radiography findings.

RESULTS

Femoral head AVN was detected in 15 of the 237 patients and 23 of the 473 femoral heads. When grade I and II activities were used as positive criteria, bone scintigraphy had a sensitivity of 91.3% (100% with pain) and specificity of 74.0% (100% with pain) for AVN diagnosis. When only grade II activity was considered positive, the rates were 56.5% (80.0% with pain) and 99.5% (100% with pain), respectively. The presence of a typical photon defect had a low sensitivity of 47.8%, although the specificity was high (99.1%).

CONCLUSIONS

The incidence of femoral head AVN was low among a prospective cohort of renal transplantation recipients at the time of 1 year after engraftment. Planar bone scintigraphy is sufficient to diagnose AVN in symptomatic patients at risk for femoral head AVN using grade I and II activities as positive criteria.

Steroid withdrawal in living donor renal transplant recipients using tacrolimus and cyclosporine: a randomized prospective study*

Steroids have been a mainstay of immunosuppressive regimens in renal transplantation despite their adverse effects. The introduction of new immunosuppressant has improved the survival rates and prompted trials of steroid withdrawal. We conducted a randomized prospective study to compare steroid withdrawal at 6 months post-transplant between tacrolimus + mycophenolate mofetil (MMF) (FK group) versus cyclosporine A + MMF (CsA group). Steroid was withdrawn at 6 months post-transplant under the condition of no rejection episode proven by biopsy and maintenance of serum creatinine level <2.0 mg/dl. Fourteen recipients were excluded because of acute rejection within 6 months or protocol violation. Steroid could be tapered off in 62 in FK group and 55 in CsA. Three cases in FK group and five in CsA had acute rejection within another 6 months after steroid withdrawal (P > 0.05). At 12 months, the incidence of post-transplant diabetes was 18.6% vs. 8.0% in FK and CsA group. And hypercholesterolemia was presented in 8.5% vs. 2.0%, hypertension in 47.5% vs. 56.0%, and serum creatinine level 1.18 +/- 0.24 mg/dl vs. 1.18 +/- 0.20 mg/dl, respectively (P > 0.05). Steroid withdrawal may be carried out successfully using both FK and CsA with MMF, but long-term follow-up is necessary.

Serum uric acid is associated with microalbuminuria in prehypertension

Serum uric acid is associated with cardiovascular disease. However, the independent role of uric acid in the development of cardiovascular disease is uncertain. This study examined the cross-sectional association of serum uric acid level with microalbuminuria among 6771 subjects without diabetes or hypertension. Blood pressure was categorized as prehypertension (systolic blood pressure, 120 to 140 mm Hg or diastolic blood pressure, 80 to 90 mm Hg) and normotension (systolic blood pressure, <120 mm Hg and diastolic blood pressure, <80 mm Hg). Microalbuminuria was found in 4.0% of normotensive subjects (n=4819) and in 7.9% of prehypertensive subjects (n=1952). Prehypertensive subjects with microalbuminuria had higher uric acid level than those with normoalbuminuria (men, 387 [68] mmol/L versus 371 [69] mmol/L; P=0.017; women 286 [56] mmol/L versus 262 [54] mmol/L; P=0.006). However, the difference in serum uric acid level according to the presence or absence of microalbuminuria was not found in the normotensive group. Multiple logistic regression models showed that, in the prehypertensive group, after adjustment for other cardiovascular risk factors, the highest uric acid quartile entailed >2 times greater risk for microalbuminuria than the lowest quartile in both men (odds ratio, 2.12; 95% CI, 1.16 to 3.87) and women (odds ratio, 3.36; 95% CI, 1.17 to 9.69). In the normotensive group, serum uric acid quartile did not show the independent association with microalbuminuria. In conclusion, serum uric acid level was strongly associated with microalbuminuria in prehypertensive subjects.

Incidence and clinical significance of human parvovirus B19 infection in kidney transplant recipients

Human parvovirus B19 (B19) infection has been known to cause chronic anemia, pure red cell aplasia (PRCA), glomerulopathy, and allograft dysfunction in kidney transplant (KT) recipients. The aim of this study was to evaluate the incidence and clinical significance of B19 infection in KT recipients. A total of 537 serum samples from 167 KT recipients were included in the present study. The incidence of B19 infection was based on either qualitative polymerase chain reaction (PCR) or quantitative PCR with LightCycler Parvovirus B19 Quantitation kit. Clinical significance of B19 infection was investigated by a retrospective review of hemoglobin (Hb) levels and the results of kidney and bone marrow biopsies. The overall PCR positive rate was 18.3% (98/537), and 52 of 167 (31.1%) KT recipients showed at least one positive PCR. In addition, 20 of 167 subjects (12.0%) showed PCR-positivity more than two consecutive times, and they had significantly lower Hb levels than those with negative or one positive PCR (p < 0.0001). Furthermore, two patients suffered from PRCA, which was confirmed by bone marrow biopsy. However, B19 infection did not seem to affect the graft outcome. In conclusion, the B19 infection in KT recipients was not uncommon and was associated with low Hb levels and PRCA after KT.

Targeted gene disruption of the heat shock protein 72 gene (hsp70.1) in the donor tissue is associated with a prolonged rejection-free survival in the murine skin allograft model

It is known that the expression level of the heat shock protein (HSP) is elevated in allograft tissues, but the specific role of the HSP in the acute rejection has not been elucidated. This study aims to determine how and when the HSP72 molecule works immunologically in the process of acute allograft rejection from a skin graft model in which HSP72 (hsp70.1 gene) knock out (KO) mice were adopted either as a donor or as a recipient. In experiment I, tail skin was grafted from either the HSP72 KO C57BL/6 mice or wild-type C57BL/6 mice--as the allograft control--onto the trunk of B10BR mice. The grafts were observed for any signs of rejection until the 14th day after the graft. The survival of the grafted skin from the two donor groups was analyzed by a log-rank method. The grafted skin was observed for the degree of rejection using light microscopy. In addition, the degree of apoptosis was assessed using a terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). A mixed lymphocyte reaction (MLR) was observed with HSP72 KO C57BL/6 splenocytes as the stimulator and B10BR mice lymphocytes as the responder cells. The cytokine levels, such as interleukin-2 (IL-2) and interferon-gamma, were measured from an MLR supernatant using enzyme-linked immunosorbent assay (ELISA). In experiment II, the tail skin was grafted in the opposite direction from the B10BR mice to the HSP72 KO or wild-type C57BL/6 mice, and the grafts were observed for any signs of rejection, as defined in experiment I. The absence of HSP72 expression was observed in the HSP72 KO mice lymphocytes after heat stress (42 degrees C) using Western blot analysis. In experiment I, the survival of the skin grafts from the HSP72 KO C57BL/6 mice was 12+/-1.3 days (median+/-S.E.), which was significantly longer than that from the allograft control donor (9+/-0.6 days; p=0.03). This coincided with the microscopic finding of the graft tissues. The MLR response of the CD4+ lymphocytes stimulated by HSP72 KO C57BL/6 splenocytes was lower, and the interferon-gamma concentration from the MLR supernatant was also lower. On Day 9, 3.7+/-1.1(mean+/-S.D.) TUNEL-positive cells per unit high-power field (HPF) were observed from the HSP72 KO C57BL/6 skin, which was significantly lower than that from the control skin (8.7+/-2.1 cells/HPF; p=0.045). In contrast, in experiment II, there was no difference in the survival of the skin graft either from the B10BR to HSP72 KO C57BL/6 mice or from the B10BR to the wild-type C57BL/6 mice. In summary, the survival of the skin grafts from the HSP72 KO C57BL/6 mice was prolonged, and the degree of rejection was lower than that from the allograft control. This means that the presence of HSP72 in the donor tissue is related to the up-regulation of acute rejection from the recipient immune system. The HSP72 KO mice as the donor were shown to have decreased level of antigen presentation to the recipient CD4+ lymphocytes. Therefore, the HSP72 molecule from the donor cells is believed to be related to the induction of the recipient immune reaction via alloantigen presentation.