Quantitative Analysis of Carbonic Anhydrase IX Uncovers Hypoxia-Related Functional Differences in Classical Hodgkin Lymphoma Subtypes

Abstract

Upregulation of carbonic anhydrase IX (CAIX) was found to be associated with unfavorable prognosis and resistance to treatment in a broad spectrum of malignancies, recently also in classical Hodgkin’s lymphoma (cHL). As demonstrated, variable CAIX expression in a significant number of cHL cases was associated with poor treatment response. The current study focused on the quantification CAIX immunopositivity and its relative expression compared to the total CD30+ neoplastic pool using digital image analysis. One hundred and one lymph node samples featuring cHL histology were analyzed for both CD30 and CAIX by immunohistochemistry. Whole histological slides were scanned and immunopositivity was determined as the histoscore (H-score) using the DensitoQuant software module (3DHistech Kft., Budapest, Hungary). CAIX positivity was observed in the HRS-cells of 56/101 cases (55.44%) and frequently observed in the proximity of necrotic foci. CAIX H-scores were highly variable (range: 2.16–90.36, mean 18.7 ± 18.8). Individual CAIX values were independent of the much higher CD30 values (range 3.46–151.3, mean 52.37 ± 30.74). The CAIX/CD30 index proved to be the highest in the aggressive lymphocyte-depleted (LD) subtype (CAIX/CD30: 0.876). The CAIX expression and the CAIX/CD30 relative index can be precisely determined by image analysis, and values reflect the extent of a tumor mass undergoing hypoxic-stress-related adaptation in the most aggressive forms of cHL.

Carbonic Anhydrase Inhibitor Acetazolamide Enhances CHOP Treatment Response and Stimulates Effector T-Cell Infiltration in A20/BalbC Murine B-Cell Lymphoma

“…The role of CAIX upregulation in the pH homeostasis of experimental lymphoma models were demonstrated [27]. According to our observations, hypoxia related adaptation and CAIX (but not CAXII) overexpression is obvious in a subset of Hodgkin's lymphomas with an adverse clinical effect [28,29]. While the metabolic heterogeneity within the lymphoma tissue is well known and can also be routinely demonstrated by in-vivo PET-imaging tools, therapeutic considerations focusing on an adaptive response are to date missing.…”

“…The expression of CAs due to hypoxic stress was reported in a series of aggressive lymphoma cell lines [27]. The increase of CAIX but not CAXII expression was associated with tissue necrosis and inferior clinical outcome in human lymphatic neoplasia, especially in progressive forms of classical Hodgkin-lymphoma [28,29]. However, attempts made for the therapeutic utilization of CAIX in lymphoma have not been reported so far.…”

Tissue microarrey: a potential cost-effective approach for mismatch repair testing in colorectal cancer

“…As mentioned earlier, little is known on the H-score formula. One study, by Orsolya Matolay et al stated that the H-score is "using individual pixel intensity levels and the total area of pixels" [20]. Therefore, it was unclear how to analyze and interpret its results.…”

“…The H-Score proved to be valid compared to light microscopy "ground truth". The group suggested explanation as to how the H-scores works resembles our appraoch for the staining intensity score [20]. However, the differences show that there are other aspects included in the H-Score calculation.…”

Sustain, Adapt, and Overcome—Hypoxia Associated Changes in the Progression of Lymphatic Neoplasia

“…Focal CAIX expression in HRS cells was associated with depressed cell proliferation capacity determined by Ki-67 nuclear positivity. CAIX expression could be measured by digital image analysis and proved to be different between the major histological subtypes of cHL (72). Moreover, cHL cases featuring selective CAIX-expression in the initial diagnostic sample showed a significantly decreased progression-free survival compared to the CAIX-negative cohort (2).…”