[Clinical examination of cases of radiation proctitis after intensity-modulated radiation therapy for prostate cancer].

In our series of 366 patients who received intensity-modulated radiation therapy (IMRT) for prostate cancer, radiation proctitis developed in 24 patients. We examined the endoscopic evidence and clinical characteristics of radiation proctitis in these patients. The onset time was 2-29 months after treatment, with bloody bowel discharge being the most common symptom (22 cases). Colonoscopy revealed that the lesions tended to be concentrated on the rectal right anterior wall. Severity, according to the Tada classification, was 0b or Ia in 70.8% of all cases. The incidence of radiation proctitis decreased, and the clinical and endoscopic findings showed only mild radiation proctitis after IMRT.

Therapy for pneumonitis and sialadenitis by accumulation of CCR2-expressing CD4+CD25+ regulatory T cells in MRL/lpr mice.

Adoptive transfer of CD4+CD25+ regulatory T cells has been shown to have therapeutic effects in animal models of autoimmune diseases. Chemokines play an important role in the development of autoimmune diseases in animal models and humans. The present study was performed to investigate whether the progression of organ-specific autoimmune diseases could be reduced more markedly by accumulating chemokine receptor-expressing CD4+CD25+ regulatory T cells efficiently in target organs in MRL/MpJ-lpr/lpr (MRL/lpr) mice. CD4+CD25+Foxp3+ T cells (Treg cells) and CD4+CD25+Foxp3+ CCR2-transfected T cells (CCR2-Treg cells) were transferred via retro-orbital injection into 12-week-old MRL/lpr mice at the early stage of pneumonitis and sialadenitis, and the pathological changes were evaluated. Expression of monocyte chemoattractant protein-1 (MCP-1)/CCL2 was observed in the lung and submandibular gland of the mice and increased age-dependently. The level of CCR2 expression and MCP-1 chemotactic activity of CCR2-Treg cells were much higher than those of Treg cells. MRL/lpr mice to which CCR2-Treg cells had been transferred showed significantly reduced progression of pneumonitis and sialadenitis in comparison with MRL/lpr mice that had received Treg cells. This was due to more pronounced migration of CCR2-Treg cells and their localization for a longer time in MCP-1-expressing lung and submandibular gland, resulting in stronger suppressive activity. We prepared chemokine receptor-expressing Treg cells and demonstrated their ability to ameliorate disease progression by accumulating in target organs. This method may provide a new therapeutic approach for organ-specific autoimmune diseases in which the target antigens remain undefined.

IK cytokine ameliorates the progression of lupus nephritis in MRL/lpr mice.

OBJECTIVE: IK cytokine has been isolated as a factor that inhibits interferon-gamma (IFNgamma)-induced expression of class II major histocompatibility complex (MHC) antigens. Aberrant expression of class II MHC antigens has reportedly been recognized in the target organs of autoimmune diseases and been associated with disease activity. In this study, we investigated whether IK cytokine can ameliorate the progression of lupus nephritis in MRL/lpr mice. METHODS: A truncated IK analog was prepared and transfected into a nonmetastatic fibroblastoid cell line, and then injected subcutaneously into MRL/lpr mice at ages 8 weeks (before the onset of lupus nephritis) and 12 weeks (at the early stage of the disease). RESULTS: An IK cytokine, when it was translated from methionine at position 316, acted as a secretory protein. This truncated IK cytokine (tIK) reduced IFNgamma-induced class II MHC expression in various cells through decreased expression of class II MHC transcription activator. Treatment of MRL/lpr mice with tIK significantly reduced renal damage as compared with control mice. A significant decrease in macrophage and T cell infiltration was found in the kidneys of tIK-treated mice, resulting in decreased production of IFNgamma and interleukin-2. Mice treated with tIK also showed significant reduction of anti-DNA antibodies and circulating immune complexes. A specific reduction of class II MHC expression was observed on B cells and monocytes as well as in the kidney. CONCLUSION: We prepared a potent IK analog and demonstrated its ability to ameliorate the progression of lupus nephritis. This agent may therefore provide a new therapeutic approach for lupus nephritis.

[Two cases of heparin-induced thrombocytopenia (HIT) and a review of the literature].

We experienced two cases of heparin-induced thrombocytopenia (HIT) which occurred during unfractionated heparin treatment. The first patient was a 72-year-old man, who was admitted to our hospital because of sudden onset dyspnea in January 2000. He was diagnosed as having a pulmonary embolism and heparin was started. Nine days later, progressive embolization of the pulmonary artery and femoral vein was found and thrombocytopenia (platelet count 20 x 10(9)/l) was observed 14 days after that. Cessation of heparin and administration of argatroban resulted in progressive normalization of the platelet count. The second patient was a 62-year-old woman, who was admitted to our hospital in April 2001, with the chief complaint of sudden onset dyspnea. She was diagnosed as having acute left-sided heart failure and heparin was started. Fifteen 15 days later, thrombocytopenia (platelet count 17 x 10(9)/l) was observed. Cessation of heparin resulted in normalization of the platelet count. Both cases were positive for anti-heparin-platelet factor 4 (PF4) antibody. Here we report on the clinical course of two cases of HIT with a review of the literature.

Identification of N-arachidonylglycine as the endogenous ligand for orphan G-protein-coupled receptor GPR18.

An orphan G-protein-coupled receptor, GPR18, was cloned on the basis of degenerate-oligonucleotide PCR analysis of HUT 102 cells using primers designed from the conservative regions of the human chemokine receptor. GPR18 was expressed significantly in lymphoid cell lines, but not in non-lymphoid hematopoietic cell lines. Moreover, the expression of the GPR18 gene was higher in peripheral lymphocyte subsets (CD4(+), CD4(+)CD45RA(+), CD4(+)CD45RO(+), CD8(+), and CD19(+)) than in monocytes and lymphoid cell lines, and was increased after stimulation with phytohemagglutinin. By screening using a lipid library, N-arachidonylglycine (NAGly) induced an increase in intracellular Ca(2+) concentration in GPR18-transfected cells, which was significantly greater than that in mock-transfected cells. NAGly also inhibited forskolin-induced cAMP production in a pertussis toxin-sensitive manner in the GPR18-transfected CHO cells. This is the first study to demonstrate that NAGly is a natural ligand for GPR18.

Antagonist of interferon-inducible protein 10/CXCL10 ameliorates the progression of autoimmune sialadenitis in MRL/lpr mice.

OBJECTIVE: Mononuclear cell infiltration of the salivary glands is a major feature of Sjögren's syndrome (SS) and its animal model. Local generation of chemokines and the presence of chemokine receptors on the infiltrating cells may be involved in this process. We undertook the present study to investigate the expression of chemokines during the development of autoimmune sialadenitis in MRL/lpr mice and the therapeutic effect of chemokine antagonists on sialadenitis. METHODS: NH2-terminal-truncated interferon-inducible protein 10 (IP-10)/CXCL10 analogs were transfected into a nonmetastatic fibroblastoid cell line, MRL/N-1, and injected subcutaneously into MRL/lpr mice, and the effects on sialadenitis were monitored. RESULTS: IP-10 analogs truncated by 5 or more amino acid residues from the N-terminal failed to induce chemotaxis and calcium influx by CXCR3-expressing cells. Of these, the most potent antagonist (AT) (IP-10-AT) was a molecule with methionine added after removal of the 5 N-terminal amino acid residues. Significantly increased expression of the Th1-associated chemokines IP-10, monokine induced by interferon-gamma/CXCL9, and interferon-inducible T cell chemoattractant/CXCL11 was induced in the ductal epithelium by interferon-gamma produced in the salivary glands, whereas expression of the Th2-associated chemokines thymus and activation-regulated chemokine (TARC)/CCL17 and monocyte-derived chemokine/CCL22 was almost undetectable during sialadenitis. Inoculation of IP-10-AT into MRL/lpr mice during the early stage of sialadenitis significantly reduced periductal mononuclear cell infiltration and parenchymal destruction compared with these features in control and TARC-AT-bearing mice. This was due to a significant reduction in infiltration of CXCR3+ T cells, predominantly Th1 cells, resulting in decreased interferon-gamma production. CONCLUSION: We prepared a novel potent IP-10 antagonist and demonstrated its ability to ameliorate the progression of autoimmune sialadenitis. This agent may provide a new therapeutic approach to SS.