High cell-free DNA is associated with disease progression, inflammasome activation and elevated levels of inflammasome-related cytokine IL-18 in patients with myelofibrosis

Myelofibrosis (MF) is a clonal hematopoietic stem cell disorder classified among chronic myeloproliferative neoplasms, characterized by exacerbated myeloid and megakaryocytic proliferation and bone marrow fibrosis. It is induced by driver (JAK2/CALR/MPL) and high molecular risk mutations coupled to a sustained inflammatory state that contributes to disease pathogenesis. Patient outcome is determined by stratification into risk groups and refinement of current prognostic systems may help individualize treatment decisions. Circulating cell-free (cf)DNA comprises short fragments of double-stranded DNA, which promotes inflammation by stimulating several pathways, including inflammasome activation, which is responsible for IL-1β and IL-18 maturation and release. In this work, we assessed the contribution of cfDNA as a marker of disease progression and mediator of inflammation in MF. cfDNA was increased in MF patients and higher levels were associated with adverse clinical outcome, a high-risk molecular profile, advanced disease stages and inferior overall survival, indicating its potential value as a prognostic marker. Cell-free DNA levels correlated with tumor burden parameters and markers of systemic inflammation. To mimic the effects of cfDNA, monocytes were stimulated with poly(dA:dT), a synthetic double-stranded DNA. Following stimulation, patient monocytes released higher amounts of inflammasome-processed cytokine, IL-18 to the culture supernatant, reflecting enhanced inflammasome function. Despite overexpression of cytosolic DNA inflammasome sensor AIM2, IL-18 release from MF monocytes was shown to rely mainly on the NLRP3 inflammasome, as it was prevented by NLRP3-specific inhibitor MCC950. Circulating IL-18 levels were increased in MF plasma, reflecting in vivo inflammasome activation, and highlighting the previously unrecognized involvement of this cytokine in MF cytokine network. Monocyte counts were higher in patients and showed a trend towards correlation with IL-18 levels, suggesting monocytes represent a source of circulating IL-18. The close correlation shown between IL-18 and cfDNA levels, together with the finding of enhanced DNA-triggered IL-18 release from monocytes, suggest that cfDNA promotes inflammation, at least in part, through inflammasome activation. This work highlights cfDNA, the inflammasome and IL-18 as additional players in the complex inflammatory circuit that fosters MF progression, potentially providing new therapeutic targets.

Pathologic vascularity of renal angiomyolipoma: cast corrosion and angiographic study

Angiomyolipomas of the kidney at times have been preoperatively identified by the interlobar or interlobular artery eneurysms in the early vascular phase of renal arteriograms. A case report is presented in which a plastic cast corrosion technique was used postnephrectomy to demonstrate the presence of aneurysms identified angiographically prior to surgery. Portions of a cast corrosion model of a hypernephroma are also exhibited to compare and contrast pathologic vascular features of both types of tumors.

Double-ended pigtail ureteral stent: useful modification to single end ureteral stent

A newly created ureteral stenting catheter of double-ended pigtail design is introduced. The pigtail design at both ends maintains the catheter in place by serving as a solid anchoring device, both intravesically and within the renal pelvis; upward or downward migration of the stent is thus prevented. It is designed also to minimize trigonal irritation. The catheter can be introduced easily either cystoendoscopically or through a percutaneous antegrade route, or by a combination of both methods. It offers the additional advantage of being readily available from an inexpensive stock source; it may be quickly and easily custom made and shaped for any ureter by the physician immediately prior to its insertion. It thus avoids having to have premanufactured, more expensive ureteral stents of different lengths. Open surgery for upper urinary tract decompression can thus be avoided.