A newly developed uroplakin II antibody with increased sensitivity in urothelial carcinoma of the bladder.

Arch Pathol Lab Med. 2014 Jul;138(7):943-9.

Hoang LL1, Tacha DE, Qi W, Yu C, Bremer RE, Chu J, Haas TS, Cheng L.

Abstract

CONTEXT:

Uroplakin II is a 15-kDa protein component of the urothelial plaques that enhance the permeability barrier and strength of the urothelium. Studies have shown uroplakin II messenger RNA to be expressed in bladder cancer tissues and peripheral blood of patients with urothelial carcinoma. Little is known about the protein expression of uroplakin II in urothelial carcinoma, possibly because of the absence of a commercially available uroplakin II antibody. Pathologists have used the uroplakin III antibody (AU1) to identify tumors of urothelial origin; however, the use of AU1 is limited because of its poor sensitivity.

OBJECTIVES:

To evaluate a newly developed mouse monoclonal uroplakin II antibody (BC21) in urothelial carcinoma and to compare it with previously developed mouse monoclonal uroplakin III (BC17 and AU1).

DESIGN:

Uroplakin II and III antibodies were optimized for staining using a horseradish peroxidase-polymer detection system and were visualized with 3,3′-diaminobenzidine.

RESULTS:

BC21, BC17, and AU1 demonstrated sensitivities in urothelial carcinoma of the bladder of 79% (44 of 56), 55% (31 of 56) (P = .002), and 34% (19 of 56) (P < .001), respectively. Subsequently, the increased staining sensitivity and intensity of BC21, compared with BC17, was validated in a larger study (134 of 174; 77% and 94 of 174; 54%, respectively) (P < .001). BC21 was found to be highly specific when evaluated in various normal and neoplastic tissues, including prostatic and renal carcinomas.

CONCLUSIONS:

The mouse monoclonal uroplakin II antibody (BC21) demonstrated superior sensitivity and specificity in urothelial carcinoma, compared with uroplakin III (BC17 and AU1), suggesting its advantages in the differential diagnosis of urothelial carcinoma and in the detection of tumors of unknown origin.

Uroplakin II (Biocare Medical)

Am J Clin Pathol. 2014 Dec;142(6):864-71.

Uroplakin II Is a More Sensitive Immunohistochemical Marker Than Uroplakin III in Urothelial Carcinoma and Its Variants.

Li W1, Liang Y1, Deavers MT1, Kamat AM2, Matin SF2, Dinney CP2, Czerniak B1, Guo CC3.

Abstract

OBJECTIVES:

Uroplakin (UP) II and UPIII are highly specific immunohistochemical markers for urothelial differentiation. Here we studied the sensitivity of UPII and UPIII in conventional and variant urothelial carcinomas (UCs).

METHODS:

uroplakin IIImmunohistochemical staining for UPII and UPIII was performed on tissue microarray slides, including 105 conventional bladder UCs (BUCs), 90 upper urinary tract UCs (UUTUCs), and 47 micropapillary, 16 plasmacytoid, 22 small cell carcinoma, and 41 sarcomatoid UC variants.

RESULTS:

UPII expression was significantly higher than UPIII expression in conventional BUC (44% vs 17%, P < .001) and UUTUC (67% vs 46%, P = .045). UPIII expression was significantly higher in UUTUC than in BUC (P < .001). In UC variants, UPII expression was significantly higher than UPIII expression in micropapillary (91% vs 25%, P < .001), plasmacytoid (63% vs 6%, P < .001), and sarcomatoid (29% vs 5%, P = .032) variants. Only rare cases of the small cell carcinoma variant had focal UPII and UPIII expression. Compared with conventional UC, the sarcomatoid variant had significantly lower UPII expression, whereas the micropapillary variant had significantly higher UPII expression (P < .001).

CONCLUSIONS:

UPII demonstrates a significantly higher sensitivity than UPIII in conventional and variant UCs. Thus, UPII is a more valuable marker than UPIII in immunohistochemical analyses for confirming the urothelial origin of carcinomas.

SOX10 and Pan Melanoma for Melanoma

sox 10Markers such as S100 and MART-1 have traditionally been used to identify melanoma.(1-2) Pan Melanoma (MART-1 and Tyrosinase) has also been shown to be a very sensitive and specific marker in metastatic melanomas.(4) But these markers are not ideal, as MART-1 and Tyrosinase have demonstrated a lack of sensitivity in desmoplastic melanoma (DM) and spindle cell melanoma (SCM) (1-2) while S100 has been shown to lack specificity.(1,3) A newer antibody, SOX10, has been shown to be a sensitive marker for melanoma including 98% of spindle and desmoplastic subtypes.(5-7) Use of SOX10 in conjunction with Pan Melanoma may provide a higher sensitivity and specificity than using S100 alone.

  • SOX10 showed equivalent sensitivity to S100
  • SOX10 & Pan Melanoma was negative in normal lymph node
  • Pan Melanoma alone only stained 50% of DM & SCM
  • 93% of all melanomas stained with SOX10 & Pan Melanoma