Efficacy and safety of CD19-specific CAR T cell-based therapy in B-cell acute lymphoblastic leukemia patients with CNSL.

Few studies have described chimeric antigen receptor (CAR) T-cell therapy for patients with B-cell acute lymphoblastic leukemia (B-ALL) with central nervous system leukemia (CNSL) because of concerns regarding poor response and treatment-related neurotoxicity. Our study included 48 patients with relapsed/refractory B-ALL with CNSL to evaluate the efficacy and safety of CD19-specific CAR T cell-based therapy. The infusion resulted in an overall response rate of 87.5% (95% confidence interval [CI], 75.3-94.1) in bone marrow (BM) disease and remission rate of 85.4% (95% CI, 72.8-92.8) in CNSL. With a median follow-up of 11.5 months (range, 1.3-33.3), the median event-free survival was 8.7 months (95% CI, 3.7-18.8), and the median overall survival was 16.0 months (95% CI, 13.5-20.1). The cumulative incidences of relapse in BM and CNS diseases were 31.1% and 11.3%, respectively, at 12 months (P = .040). The treatment was generally well tolerated, with 9 patients (18.8%) experiencing grade ≥3 cytokine release syndrome. Grade 3 to 4 neurotoxic events, which developed in 11 patients (22.9%), were associated with a higher preinfusion disease burden in CNS and were effectively controlled under intensive management. Our results suggest that CD19-specific CAR T cell-based therapy can induce similar high response rates in both BM and CNS diseases. The duration of remission in CNSL was longer than that in BM disease. CD19 CAR T-cell therapy may provide a potential treatment option for previously excluded patients with CNSL, with manageable neurotoxicity. The clinical trials were registered at www.clinicaltrials.gov as #NCT02782351 and www.chictr.org.cn as #ChiCTR-OPN-16008526.

Associations of granulocyte colony-stimulating factor with toxicities and efficacy of chimeric antigen receptor T-cell therapy in relapsed or refractory multiple myeloma.

BACKGROUND AIMS: Few studies have reported the associations of granulocyte colony-stimulating factor (G-CSF) with cytokine release syndrome (CRS), neurotoxic events (NEs) and efficacy after chimeric antigen receptor (CAR) T-cell therapy for relapsed or refractory (R/R) multiple myeloma (MM). We present a retrospective study performed on 113 patients with R/R MM who received single anti-BCMA CAR T-cell, combined with anti-CD19 CAR T-cell or anti-CD138 CAR T-cell therapy. METHODS: Eight patients were given G-CSF after successful management of CRS, and no CRS re-occurred thereafter. Of the remaining 105 patients that were finally analyzed, 72 (68.6%) received G-CSF (G-CSF group), and 33 (31.4%) did not (non G-CSF group). We mainly analyzed the incidence and severity of CRS or NEs in two groups of patients, as well as the associations of G-CSF timing, cumulative dose and cumulative time with CRS, NEs and efficacy of CAR T-cell therapy. RESULTS: Both groups of patients had similar duration of grade 3-4 neutropenia, and the incidence and severity of CRS or NEs.There were also no differences in the incidence and severity of CRS or NEs between patients with the timing of G-CSF administration ≤3 days and those >3 days after CAR T-cell infusion. The incidence of CRS was greater in patients receiving cumulative doses of G-CSF >1500 µg or cumulative time of G-CSF administration >5 days. Among patients with CRS, there was no difference in the severity of CRS between patients who used G-CSF and those who did not. The duration of CRS in anti-BCMA and anti-CD19 CAR T-cell-treated patients was prolonged after G-CSF administration. There were no significant differences in the overall response rate at 1 and 3 months between the G-CSF group and the non-G-CSF group. CONCLUSIONS: Our results showed that low-dose or short-time use of G-CSF was not associated with the incidence or severity of CRS or NEs, and G-CSF administration did not influence the antitumor activity of CAR T-cell therapy.

Factors associated with infection events after chimeric antigen receptor T-cell therapy for relapsed or refractory multiple myeloma.

OBJECTIVES: Chimeric antigen receptor (CAR) T-cell therapy is a new and effective method in relapsed or refractory (R/R) multiple myeloma (MM). This study was aimed to explore the risk factors of infection events. METHODS: We retrospectively analyzed 68 patients with R/R MM who received CAR T-cell therapy at the Affiliated Hospital of Xuzhou Medical University from June 2017 to June 2021.35 patients received anti-CD19 combined with anti-BCMA CAR T-cell therapy and 33 patients received anti-BCMA CAR T-cell therapy alone. RESULTS: Infection events in patients who received ≥4 prior lines of treatment or with grade 3-5 cytokines released syndrome (CRS) mainly occurred within 4 months after CAR T-cell infusion(CTI). The duration of infection-free survival was positively correlated with progression-free survival of patients with R/R MM (R2 = 0.962, p < 0.001) and the first infection event was closely accompanied by the disease relapse or progression. Treatment lines (p = 0.05), duration of ANC<500 cells/mm3 after CTI (p = 0.036), CRS grade (p = 0.007) and treatment response (p < 0.001) were the independent risk factors associated with infection for a multivariable model. The infection incidence was higher in patients with dual CAR T-cell therapy than with mono CAR T-cell therapy18 months after CTI although no statistic differences were observed within 18 months. CONCLUSIONS: Infections after CTI were closely associated with more lines of prior treatment, longer duration of ANC<500 cells/mm3, higher grade CRS and poor treatment response. Infections tended to occur in the early stage after CTI in patients with more lines of prior treatment and higher grade CRS.

Downregulation of long non-coding RNA TUG1 suppresses tumor growth by promoting ubiquitination of MET in diffuse large B-cell lymphoma.

Long non-coding RNAs (lncRNAs) can modulate gene expression through different mechanisms, but the fundamental molecular mechanism between lncRNAs and MET protein in diffuse large B-cell lymphoma (DLBCL) was poorly understood. The expression of lncRNA TUG1 and MET in DLBCL tissues and cell lines was determined by quantitative real-time PCR and western blotting. Cell proliferation, invasion and apoptosis were determined by cell counting kit-8 assay, transwell assay and flow cytometer. The animal xenograft model was established by the injection of DLBCL cells carrying si-TUG1. The expression of TUG1 and MET was upregulated in DLBCL tissues and cells. We demonstrated that MET was altered in the TUG1 knockdown DLBCL cells, and confirmed the interaction between TUG1 and MET by RNA pull-down and RNA immunoprecipitation. Furthermore, knockdown of TUG1 reduced MET protein level by promoting ubiquitination, and suppressed tumor growth in vitro and in vivo. Our findings demonstrated that TUG1 exerted its oncogenic function in DLBCL by inhibiting the ubiquitination and the subsequent degradation of MET. Knockdown of TUG1 through MET downregulation suppressed DLBCL cell proliferation and tumor growth.

Effects of pamidronate disodium on the loss of osteoarthritic subchondral bone and the expression of cartilaginous and subchondral osteoprotegerin and RANKL in rabbits.

BACKGROUND: Osteoarthritis (OA) is a major health problem in the increasingly elderly population. Therefore, it is crucial to prevent and treat OA at an early stage. The present study investigated whether pamidronate disodium (PAM), a bone-loss inhibitor, can significantly prevent or reverse the progression of early anterior cruciate ligament transection (ACLT)-induced OA. Whether therapeutic intervention is associated with regulation of the expression of osteoprotegerin (OPG), receptor activator of nuclear factor-κB ligand (RANKL), metalloproteinase-9 (MMP-9) or Toll-like receptor-4 (TLR-4) in cartilage and/or subchondral bone was also investigated. METHODS: 60 New Zealand rabbits were randomized into four groups: Sham-operated (n = 20); ACLT (n = 20); short-term treatment with PAM (PAM-S, n = 10) and long-term treatment with PAM (PAM-L, n = 10). For cartilage and subchondral bone testing, rabbits from Sham and ACLT groups were harvested at 2, 4, 6, and 14 weeks. Rabbits were given PAM from the 4th week after ACLT operation in PAM-S and PAM-L group, and were harvested at 6 and 14 weeks, respectively. Trabecular characteristics and cartilage changes were detected using Micro-CT, safranin O and rapid green staining, respectively. Immunohistochemical staining for OPG and RANKL were also performed. OPG, RANKL, MMP-9 and TLR-4 expression was evaluated by western blot analysis. RESULTS: Micro-CT and histology analyses indicated that PAM treatment for 2 or 10 weeks could completely prevent or reverse osteoarthritic subchondral bone loss and cartilage surface erosion. Immunohistochemistry and western blot analysis indicated that expression of OPG and RANKL increased, although RANKL expression increased more significantly than that of OPG. Therefore the ratio of OPG to RANKL was lower in the ACLT group. However, the ratio of OPG to RANKL in the PAM group was significantly higher than that in the ACLT group. Additionally, expression of MMP-9 and TLR-4 were upregulated in the ACLT group and downregulated in the PAM treated groups. CONCLUSIONS: PAM can significantly inhibit and even reverse early osteoarthritic subchondral bone loss, thus alleviating the process of cartilaginous degeneration. The mechanisms involved may be associated with the upregulation of OPG expression, and downregulation of RANKL, MMP-9 and TLR-4 expression.

Immunotherapies targeting GPRC5D in relapsed or refractory multiple myeloma: latest updates from 2022 ASH Annual Meeting.

B cell maturation antigen (BCMA)-targeted immunotherapy has shown unprecedented results in the treatment of relapsed or refractory (R/R) multiple myeloma (MM). However, disease progression remains an issue attributed to variable BCMA expression, BCMA downregulation, and heterogeneity of tumor antigens in MM. Therefore, additional treatment options with novel therapeutic targets are warranted. G protein-coupled receptor, class C group 5 member D (GPRC5D), an orphan receptor expressed on malignant plasma cells with limited expression in normal tissue, has emerged as a promising therapeutic target for R/R MM. GPRC5D-targeted chimeric antigen receptor (CAR)-T and CAR-NK cell therapy, as well as bispecific T cell engagers, offer remarkable anti-tumor activities. We summarized some latest reports on GPRC5D-targeted treatments for R/R MM from the 2022 ASH Annual Meeting (ASH 2022).

Anti-G Protein-Coupled Receptor, Class C Group 5 Member D Chimeric Antigen Receptor T Cells in Patients With Relapsed or Refractory Multiple Myeloma: A Single-Arm, Phase â ¡ Trial.

PURPOSE: G protein-coupled receptor, class C group 5 member D (GPRC5D) is considered to be a promising surface target for multiple myeloma (MM) immunotherapy. Here, we report the efficacy and safety of anti-GPRC5D chimeric antigen receptor (CAR) T cells in patients with relapsed or refractory (R/R) MM. METHODS: This phase Ⅱ, single-arm study enrolled patients (18-70 years) with R/R MM. Lymphodepletion was performed before patients received 2 × 106/kg anti-GPRC5D CAR T cells. The primary end point was the proportion of patients who achieved an overall response. Safety was also evaluated in eligible patients. RESULTS: From September 1, 2021, to March 23, 2022, 33 patients were infused with anti-GPRC5D CAR T cells. At a median follow-up of 5.2 months (range, 3.2-8.9), the overall response rate was 91% (95% CI, 76 to 98; 30 of 33 patients), including 11 (33%) stringent complete responses, 10 (30%) complete responses, four (12%) very good partial responses, and five (15%) partial responses. Partial responses or better were observed in nine (100%) of nine patients with previous anti-B-cell maturation antigen (BCMA) CAR T-cell therapy, including two patients who had received repeated anti-BCMA CAR T-cell infusions with no responses at the last time. Grade 3 or higher hematologic toxicities were neutropenia (33 [100%]), anemia (17 [52%]), and thrombocytopenia (15 [45%]). Cytokine release syndrome occurred in 25 (76%) of 33 patients (all were grade 1 or 2), and neurotoxicities in three patients (one grade 2 and one grade 3 ICANSs and one grade 3 headache). CONCLUSION: Anti-GPRC5D CAR T-cell therapy showed an encouraging clinical efficacy and manageable safety profile in patients with R/R MM. For patients with MM that progressed after anti-BCMA CAR T-cell therapy or that is refractory to anti-BCMA CAR T cell, anti-GPRC5D CAR T-cell therapy might be a potential alternative option.

Long-Term Follow-Up of Combination of B-Cell Maturation Antigen and CD19 Chimeric Antigen Receptor T Cells in Multiple Myeloma.

PURPOSE: A combination of anti-B-cell maturation antigen (BCMA) and anti-CD19 chimeric antigen receptor (CAR) T cells induced high response rates in patients with relapsed or refractory (R/R) multiple myeloma (MM), but long-term outcomes have not been assessed yet. PATIENTS AND METHODS: In this single-arm, phase II trial, patients with R/R MM received a combination of anti-BCMA CAR T cells and anti-CD19 CAR T cells at a dose of 1 × 106 cells/kg, after receiving a conditioning chemotherapy consisting of cyclophosphamide and fludarabine. The overall response, long-term outcomes, and safety were assessed, as were their associations with clinical and disease characteristics. RESULTS: Of 69 enrolled patients, 62 received the combined infusion of anti-BCMA and anti-CD19 CAR T cells with a median follow-up of 21.3 months. The overall response rate was 92% (57/62), and complete response or better was observed in 37 patients (60%). Minimal residual disease-negativity was confirmed in 77% (43/56) of the patients with available minimal residual disease detection. The estimated median duration of response was 20.3 months (95% CI, 9.1 to 31.5). The median progression-free survival was 18.3 months (95% CI, 9.9 to 26.7), and the median overall survival was not reached. Patients with extramedullary disease had significantly inferior survival. Fifty-nine patients (95%) had cytokine release syndrome, with 10% grade 3 or higher. Neurotoxic events occurred in seven patients (11%), including 3% grade 3 or higher. Late adverse effects were rare, except for B-cell aplasia, hypogammaglobulinemia, and infections. CONCLUSION: The combination of anti-BCMA and anti-CD19 CAR T cells induced durable response in patients with R/R MM, with a median progression-free survival of 18.3 months and a manageable long-term safety profile.

Efficacy and safety of CD19-specific CAR-T cell-based therapy in secondary central nervous system lymphoma.

Encouraging response has been achieved in relapsed/refractory (R/R) B-cell lymphoma treated by chimeric antigen receptor T (CAR-T) cells. The efficacy and safety of CAR-T cells in central nervous system lymphoma (CNSL) are still elusive. Here, we retrospectively analyzed 15 patients with R/R secondary CNSL receiving CD19-specific CAR-T cell-based therapy. The patients were infused with CD19, CD19/CD20 or CD19/CD22 CAR-T cells following a conditioning regimen of cyclophosphamide and fludarabine. The overall response rate was 73.3% (11/15), including 9 (60%) with complete remission (CR) and 2 (13.3%) with partial remission (PR). During a median follow-up of 12 months, the median progression-free survival (PFS) was 4 months, and the median overall survival (OS) was 9 months. Of 12 patients with systemic tumor infiltration, 7 (58.3%) achieved CR in CNS, and 5 (41.7%) achieved CR both systemically and in CNS. Median DOR for CNS and systemic disease were 8 and 4 months, respectively. At the end point of observation, of the 7 patients achieved CNS disease CR, one was still alive with sustained CR of CNS disease and systemic disease. The other 6 died of systemic progression. Of the 15 patients, 11 (73.3%) experienced grades 1-2 CRS, and no patient had grades 3-4 CRS. Immune effector cell-associated neurotoxicity syndrome (ICANS) occurred in 3 (20%) patients, including 1 (6.6%) with grade 4 ICANS. All the CRS or ICANS were manageable. The CD19-specific CAR-T cell-based therapy appeared to be a promising therapeutic approach in secondary CNSL, based on its antitumor effects and an acceptable side effect profile, meanwhile more strategies are needed to maintain the response.

Prognostic Analysis of Patients with Primary Extranodal Lymphoma: A Retrospective Study.

BACKGROUND: Originating from extranodal organs or tissues, primary extranodal lymphoma (PENL) acts in different primary sites with diverse clinical performances and PENL has remarkable geographical differences and lacks the relevant reports in each region. PATIENTS AND METHODS: Two hundred and twenty PENL patients were enrolled, and the relevant clinical and laboratory indicators were analyzed. In addition, statistical methods were applied to analyze the effects of different factors on overall survival (OS) and progression-free survival (PFS) of patients. RESULTS: The three most frequent primary sites of PENL are the digestive system, head and neck, and central nervous system. The patients were classified into groups based on their risk status, resulting in low-risk, medium-low-risk, medium-high-risk, and high-risk, and their respective 3-year OS values were calculated, which showed that 121 patients (55%) were in the low-risk group and 3-year OS was 85.2% (25.9% medium-low-risk, 3-year OS 66.6%; 15% medium-high-risk, 3-year OS 61.9%; 4.09% high risk, 3-year OS 45.7%). A multivariate analysis of the Cox regression demonstrated that serum beta 2-microglobulin (ß2-MG) and lactate dehydrogenase (LDH) were independent prognostic factors for OS and PFS, respectively. Both the performance status and pathological subtypes were independent prognostic factors for OS and PFS. CONCLUSION: The correlated independent risk factors such as ß2-MG, LDH, performance status, and pathological subtypes, were helpful for effectively determining the prognosis of PENL patients and guiding treatment.

Humoral immune reconstitution after anti-BCMA CAR T-cell therapy in relapsed/refractory multiple myeloma.

Systematic and dynamic humoral immune reconstitution is little-known for patients with relapsed/refractory (R/R) multiple myeloma (MM) who received anti-B-cell maturation antigen (BCMA) chimeric antigen receptor (CAR) T-cell therapy. We investigated the kinetics of B-cell, normal plasma cell, and immunoglobulin recovery in 40 patients who achieved ongoing response after anti-BCMA CAR T-cell therapy. All patients developed B-cell aplasia and the median duration of B-cell aplasia was 70 days (range, 23-270). The B-cell count reached its nadir on median day 7 and returned to baseline level on median day 97. BCMA+ cells in bone marrow turned undetectable on median day 28 (13-159) in 94.87% (37 of 39) of patients. Normal plasma cells in bone marrow were first redetected on median day 212. All patients developed a significant decrease in serum IgG, IgA, and IgM on median day 60. At year 1, recovery of serum IgG, IgM, and IgA was observed in 53.33% (8 of 15; non-IgG MM), 73.08% (19 of 26; non-IgM MM), and 23.81% (5 of 21;non-IgA MM) of the patients, respectively. Median time to IgG, IgM, and IgA recovery were days 386, 254, and not reached during follow-up, respectively. Virus-specific IgG levels decreased with loss of protection. Twenty-three of 40 (57.5%) patients had a total of 44 infection events. There were no infection-related deaths. These results reveal a 7-month aplasia of bone marrow normal plasma cells and longer period of hypogammaglobulinemia, suggesting a profound and lasting humoral immune deficiency after anti-BCMA CAR T-cell therapy, especially for IgA.

Splenic Diffuse Red Pulp Small B-Cell Lymphoma with Gastrointestinal Hemorrhage: A Case Report and Literature Review.

BACKGROUND: Splenic diffuse red pulp small B-cell lymphoma (SDRPSBCL) is rare and accounts for less than 1% of non-Hodgkin's lymphoma. As the first or accompanying symptoms of SDRPSBCL, gastrointestinal hemorrhage (GIH) is rather unusual. PATIENTS AND METHODS: We reported on a patient with SDRPSBCL complicated with GIH. According to the enteroscopy, pathological sections of spleen and intestine, immunohistochemistry and other related laboratory examinations, the patient was diagnosed as SDRPSBCL (stage IVb) complicated with colon and rectal ulcers. The clinical manifestations were hematochezia, unformed stool, continuous anal pain and poor quality of life. Subsequently, the patient was treated by six cycles of CHOP (cyclophosphamide + doxorubicin + vincristine + hydroprednisone) regimens. The clinical features, diagnosis and treatment were analyzed retrospectively and the relevant literatures were reviewed. RESULTS: After the first course of chemotherapy, the patient did not have any more bloody stool and the stool was shaped. After six cycles of chemotherapy, the patient's anus was no longer painful and he has been in complete remission according to the result of positron emission tomography CT. CONCLUSION: Through analysis of this case, we could elucidate that after the primary disease was alleviated, the bleeding degree of digestive tract was relieved, which provided the basis for the clinical treatment of this rare disease.

Successful treatment of a patient with Philadelphia chromosome-positive acute lymphoblastic leukemia complicated by bone marrow necrosis and acute renal insufficiency: A case report.

Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL) complicated by bone marrow necrosis (BMN) and acute renal insufficiency (ARI) is rare in clinical practice. The aim of the present study was to summarize the clinical characteristics and treatment methods of a case of Ph+ ALL complicated by BMN and ARI. A 23-year-old male patient presented with pyrexia and a 2-month history of bone pain, and was diagnosed with Ph+ ALL complicated with BMN and ARI on peripheral blood tests, blood biochemistry tests, BM smear and fluorescence in situ hybridization. The patient underwent repeated hemodialysis, imatinib combination and maintenance chemotherapy, followed by allogeneic hematopoietic stem-cell transplantation. Some of the clinical signs and symptoms were alleviated, whereas others disappeared, and renal function was restored to normal. BM aspiration confirmed absence of necrosis and null lymphoblasts. Therefore, timely accurate diagnosis and effective treatment are crucial for patients with Ph+ ALL exhibiting potentially fatal complications.

Artesunate attenuates unilateral ureteral obstruction-induced renal fibrosis by regulating the expressions of bone morphogenetic protein-7 and uterine sensitization-associated gene-1 in rats.

PURPOSE: Kidney fibrosis is the most common final stage of progressive renal disease. Bone morphogenetic protein-7 (BMP-7) has been shown to be important in both preservation of kidney function and resistance to injury. Recently, it has been realized that uterine sensitization-associated gene-1 (USAG-1) functions as a kidney-specific BMP antagonist. Because of the reported anti-fibrotic effects of artesunate (Art), this study was designed to investigate the effects of Art on renal fibrosis in unilateral ureteral obstruction (UUO) rats and to explore the underlying mechanisms. METHODS: Thirty male Sprague-Dawley rats were randomly divided into five groups: Sham group, UUO group, low-dose Art-treated (Art-L), middle-dose Art-treated (Art-M), and high-dose Art-treated (Art-H) groups. The UUO rat model was established by ligating the left ureter. Fourteen days later, interstitial collagen deposition, expression of USAG-1, BMP-7, E-cadherin, α-smooth muscle actin (α-SMA), fibronectin (FN), collagen I, as well as the inflammatory infiltration levels in the kidneys were assessed. RESULTS: Art treatment significantly attenuated the deposition of interstitial collagens in the UUO rats' kidneys and exhibited the ability to improve renal function, followed by the up-regulated expression of BMP-7 and E-cadherin and the down-regulated expression of USAG-1 and α-SMA. In addition, increased macrophages infiltration in the kidneys of the UUO rats were also attenuated by the administration of Art. CONCLUSIONS: These results indicate that Art is able to improve the renal function decline and renal fibrosis induced by UUO, which may be associated with the up-regulation of BMP-7 and down-regulation of USAG-1. Accordingly, Art may become a potential preventive or therapeutic agent for chronic kidney diseases.

Cardioprotective effect of betulinic Acid on myocardial ischemia reperfusion injury in rats.

Objectives. This study aims to investigate the effect of betulinic acid (BA) on myocardial ischemia reperfusion/injury in an open-chest anesthetized rat model. Methods. The model was induced by 30 minutes left anterior descending occlusion followed by 2 hours reperfusion. There are six groups in our present study: sham operation group, ischemia/reperfusion group, low-dosage BA group, medium-dosage BA group, high-dosage BA group, and fosinopril sodium group. Rats in the latter four groups were administrated with BA (50, 100, and 200 mg/kg, i.g.) or fosinopril sodium (10 mg/kg, i.g.) once a day for 7 days before operation, respectively. Rats in the former two groups were given the same volume of vehicle (0.5% CMC-Na, i.g.). During the operation, cardiac function was continuously monitored. Serum LDH and CK were measured with colorimetric assays. The expression of Bcl-2 and Bax and the apoptosis of cardiomyocytes were investigated with western blot and TUNEL assay, respectively. Results. Pretreatment with BA improved cardiac function and attenuated LDH and CK activities compared with IR group. Further investigation demonstrated that the expression of Bcl-2 and Bax and TUNEL assay was in line with the above results. Conclusion. BA may reduce the release of LDH and CK, prevent cardiomyocytes apoptosis, and eventually alleviate the extent of the myocardial ischemia/reperfusion injury.

Roles of MAPKAPK-2 and HSP27 in the reduction of renal ischemia-reperfusion injury by ischemic postconditioning in rats.

PURPOSE: Ischemic postconditioning is a procedure during which intermittent reperfusions are performed in the early phase of reperfusion to protect organs from ischemia/reperfusion injury. And in this study, we mainly investigated the injury-alleviative role of mitogen-activated protein kinase-activating protein kinase-2 (MAPKAPK-2) and heat shock protein 27 (HSP27) in renal ischemic reperfusion injury during the procedure of ischemic postconditioning. METHODS: Sprague-Dawley rats were randomly divided into four groups. The injury models were prepared by clipping the left renal pedicle of rats after ligating the right renal pedicle for 60 min. In the ischemic postconditioning group, sequential reperfusions were done for 10 s and another ischemia for 10 s for six cycles after kidney ischemia for 60 min. In addition, the specific inhibitor SB203580 was injected through caudal vein before ischemia. Serum creatinine, blood urea nitrogen and the expression of HSP27 and MAPKAPK-2 were detected 1, 3, 6 and 24 h later after reperfusion. Furthermore, phosphorylation of HSP27 and MAPKAPK-2 protein contents, histological changes and apoptosis were compared 24 h later after reperfusion. RESULTS: Our data showed that ischemic postconditioning attenuated the renal dysfunction and cell apoptosis induced by I/R and increased phosphorylation of MAPKAPK-2 and HSP27. The results indicated that ischemic postconditioning decreased apoptosis and improved renal function. CONCLUSIONS: Taken together, it is suggested that the renal protective effect may be related to the levels of HSP27 and MAPKAPK-2 activation.