Ana Cortesão Costa

<h3>Abstract</h3> Vessel co-option in colorectal cancer liver metastases (CRCLM) has been recognized as one of the mechanistic pathways that contribute to resistance against anti-angiogenic therapy. In vessel co-opted CRCLM lesions, the cancer cells are highly motile that move toward and along the pre-existing sinusoidal vessels and hijack them to gain access to nutrient. The movement of cancer cells is accompanied by replacement of the hepatocytes. However, the molecular mechanisms by which this replacement occurs are unclear yet. To examine the involvement of apoptosis in hepatocytes replacement by cancer cells in co-opted lesions, we conducted immunohistochemical staining for chemonaïve CRCLM specimens using pro-apoptotic markers antibody, such as cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase-1 (PARP-1). The results suggested overexpression of pro-apoptotic markers in liver parenchyma of co-opted lesions compared to angiogenic lesions, specifically the hepatocytes that are in close proximity to the cancer cells. Importantly, co-culturing hepatocytes with colorectal cancer cells induced overexpression of pro-apoptotic markers in the hepatocytes. Altogether, these results propose that cancer cells could exploit apoptosis to replace the hepatocytes and establish vessel co-option in CRCLM.

Tubulointerstitial nephritis and uveitis syndrome (TINU) is a rare oculorenal inflammatory entity with a probable autoimmune etiology. Interstitial nephritis may be asymptomatic and usually has a benign course with spontaneous resolution. Uveitis, instead, is classically anterior, bilateral, and nongranulomatous, but it can be unilateral and presents as posterior uveitis or panuveitis, sometimes with a chronic or recurrent evolution. The frequent time lag of ocular and renal manifestations makes this diagnosis particularly challenging. The authors describe four cases of this rare entity, two with tubulointerstitial nephritis preceding ocular manifestations and the remaining, instead, with uveitis preceding renal involvement. The therapeutic approach included systemic corticosteroids in all cases. The addition of immunosuppressive therapy was required in three patients to achieve uveitis control. TINU is probably an underrecognized entity and should always be considered in the differential diagnosis of a chronic or recurrent idiopathic uveitis, especially in young patients who may have mild and asymptomatic renal disease.

One of the most common causes of rapidly progressive glomerulonephritis (RPGN) is pauci-immune crescentic glomerulonephritis (CrGN). In the majority of cases, this condition has a positive serologic marker, the anti-neutrophil cytoplasmic antibodies (ANCAs), but in approximately 10% there are no circulating ANCAs, and this subgroup has been known as the ANCA-negative pauci-immune CrGN. RPGN can be associated with systemic diseases, but there are only few case reports describing the association with mixed connective tissue disease (MCTD). The authors report a case of ANCA-negative CrGN associated with a MCTD.