Interleukin (IL)-18 is produced by leukocytes and renal parenchymal cells (tubular epithelial cells, podocytes, and mesangial cells). The IL-18 receptor (IL-18R) is expressed on these cells in cisplatin-induced acute kidney injury, but the role of IL-18R is unknown. To help define this, we compared IL-18Rα knockout with wild-type mice in cisplatin-induced acute kidney injury and found deteriorated kidney function, tubular damage, increased accumulation of leukocytes (CD4(+) and CD8(+) T-cells, macrophages, and neutrophils), upregulation of early kidney injury biomarkers (serum TNF, urinary IL-18, and KIM-1 levels), and increased expression of pro-inflammatory molecules downstream of IL-18. In vitro, leukocytes from the spleen and kidneys of the knockout mice produced greater amounts of pro-inflammatory cytokines upon stimulation with concanavalin A compared to that in wild-type mice. Levels of the suppressor of cytokine signaling 1 and 3 (negative regulators of cytokine signaling) were reduced in the spleen and kidneys of IL-18Rα-deficient compared to wild-type mice. Adoptive transfer of wild-type splenocytes by IL-18Rα-deficient mice led to decreased cisplatin nephrotoxicity compared to control IL-18Rα-deficient mice. In contrast, anti-IL-18Rα and anti-IL-18Rβ antibody treatment tended to increase cisplatin nephrotoxicity in wild-type mice. Thus, signaling through IL-18Rα activates both inflammation-suppressing and pro-injury pathways in cisplatin-induced acute kidney injury.

These data suggest the potential use of the u-Kim-1 levels to screen for active LN and for the estimation of t-Kim-1 expression in renal biopsies to predict renal damage, ongoing glomerular nephritis and tubulointerstitial inflammation, and tubular atrophy.

BackgroundInterleukin (IL)-18 is markedly elevated in systemic inflammatory diseases that cause the ‘cytokine storm’ such as adult-onset Still’s disease (AOSD) and hemophagocytic lymphohistiocytosis (HLH). The differences in IL-18 between AOSD and HLH, especially in adults, is uncertain. Macrophage activation syndrome (MAS), a form of secondary HLH, is often difficult to differentiate cases of AOSD that include MAS from other secondary HLH. In this case-control study, we investigated whether serum IL-18 levels could be a useful biomarker for the differential diagnosis of AOSD with or without MAS (AOSD group) and other secondary HLH in adults (adult HLH group).Patients and MethodsWe enrolled 46 patients diagnosed with AOSD including 9 patients with MAS and 31 patients in the adult HLH group, which excluded AOSD-associated MAS. The clinical features and laboratory data were compared between the AOSD and adult HLH groups. In addition, we subdivided the AOSD group (with or without MAS) and the adult HLH group (whether lymphoma-associated or not) and compared the four groups. A logistic regression analysis was used to identify factors with high efficacy in differentiating the two groups, followed by a receiver operating characteristic (ROC) curve analysis to evaluate the differential diagnostic ability of IL-18. We analyzed the correlation between IL-18 and various laboratory parameters in the AOSD group.ResultsSerum IL-18 levels of patients in the AOSD groups were significantly higher than those of the adult HLH groups, and were closely correlated with ferritin, soluble interleukin-2 receptor (sIL-2R), and other laboratory data. Univariate and multivariate logistic regression analyses revealed that IL-18, sIL-2R, and ‘arthralgia or arthritis’ are independent factors useful in the differential diagnosis of AOSD from adult HLH. In the differential diagnosis of both groups, the area under the curve obtained from the ROC curve of IL-18 with a cutoff value of 18,550 pg/mL was 0.91 (95% confidence interval 0.83–1.00; sensitivity 90.3%, specificity 93.5%), and the differential diagnosis ability of IL-18 was superior to that of other laboratory data.ConclusionsIL-18 could be a useful biomarker for the differential diagnosis of AOSD and adult HLH.

Introduction Osteoporosis is one of the serious adverse effects associated with glucocorticoid therapy. Although bisphosphonates have been used for glucocorticoid-induced osteoporosis (GIO), some patients have shown an inadequate response. In such cases, denosumab or teriparatide are used. However, there is no consensus on which of these two drugs is superior. We prospectively compared denosumab's and teriparatide's effects on the bone mineral density (BMD) in GIO patients with prior bisphosphonate treatment. Materials and methods After receiving oral bisphosphonates for ≥2 years, GIO patients with low T-score BMD (<−2.5) were switched from bisphosphonates to denosumab (n = 20) or daily teriparatide (n = 21). We measured the BMD (lumbar spine, femoral neck, and total hip) in both groups every 6 months for 24 months. Results At 24 months of treatment, the lumbar spine BMD increased significantly from baseline in both the denosumab and teriparatide groups (baseline vs. denosumab and teriparatide; 5.9 ± 5.6%, P < 0.001 and 7.9 ± 5.4%, P < 0.001). A significant increase in femoral neck BMD from baseline occurred only in the teriparatide group (6.6 ± 10.8%, P < 0.05); denosumab (1.5 ± 5.0%). No significant changes occurred in the total hip BMD from baseline in either group (−0.1 ± 5.6% and 3.3 ± 7.5%, respectively). There was no significant difference between the denosumab and teriparatide groups at 24 months in lumbar spine and femoral neck BMD, but was significantly higher in the teriparatide group at 12 months (P < 0.01 and P < 0.05 in the lumbar spine and femoral neck, respectively). Conclusion Teriparatide might have some advantages over denosumab and be a good alternative for treating GIO patients with prior bisphosphonate treatment.

Objective: Ultrasound (US) is more sensitive and reliable than a clinical examination, and is better correlated with the disease activity in rheumatoid arthritis (RA). We conducted the present study to assess the value of US as a screening tool to predict therapeutic responses in RA patients treated with anti-tumor necrosis factor (TNF) drugs. Methods: We retrospectively analyzed the cases of 86 consecutive RA patients who were classified by their DAS28-CRP scores at the 54th week. We assessed two US findings (i.e., the synovial hypertrophy index [SHI] and synovial vascularization) by grey-scale imaging and the Doppler synovitis index (DSI). Results: When we applied cutoff points determined by a ROC curve analysis, patients with a lower total SHI (34) or DSI (7) at baseline were significantly more likely to reach remission (44 patients, 51.2%) as shown by the DAS28-CRP at 54 weeks. On the basis of these cutoff values, we dichotomized all variables and performed a logistic regression analysis using the 54-weeks data; the only predictive factors of remission with anti-TNF therapy were the patients' baseline DAS28-CRP 2.7 as low disease activity/remission, and the SHI. Conclusion: An ultrasound assessment would be a highly useful predictor of the achievement of clinical remission.