analyzed MCL cases and recognized that only 60% of cases were positive for CD52, but the difference in the immunohistochemical technique used may explain the distinct results.25 Since fluorescence intensity steps are important determinants in the analysis of leukemias and lymphomas,26 reliable methods for measuring MFI are important for the correct data interpretation, and, consequently, correct classification of hematological malignancies. leukemia, chronic lymphocytic leukemia and hairy cell leukemia cases. CD123 showed higher mean fluorescence intensities in hairy cell leukemia cells. Chronic lymphocytic leukemia, atypical chronic lymphocytic leukemia and mantle cell lymphoma experienced higher expression of CD43 and all follicular lymphoma cases had very low imply fluorescence intensity values. CD52 expression was consistently positive among all cases. Conclusion Quantitative evaluation of these markers can be a useful additional tool to better identify some types of mature B-cell neoplasms. acute myeloid leukemia (AML),14 and SL-101, an anti-CD123 antibody-conjugate, is usually under study for the treatment of CD123-positive AML.15 The results of the current study are in agreement with previous studies investigating the higher expression of this marker in HCL,16, 17 since higher MFI values were identified in HCL cases and a pattern of HCL to have higher CD123 expression compared to HCLv cases was also observed. This study recognized a higher expression of CD123 in SMZL compared to CLL, LPL and follicular lymphoma cases. According to a previous study, CD43 expression is similar among CD10-positive MBCN (follicular lymphoma, Burkitt lymphoma and DLBCL), one of the most complicated differential diagnoses.18 All five cases of follicular lymphoma experienced extremely HBX 19818 low expressions when compared to aCLL, CLL and HBX 19818 MCL, and the only case of DLBCL expressed this marker at an intermediate intensity as explained by previous studies,19 however, analysis of this group was impaired by the low frequency of cases. During the ontogeny of B-cells, CD43 is usually expressed in early stages and is lost in intermediate stages, but it is usually expressed again in plasma cells and activated mature B-cells.20 In agreement with the literature, these results identified higher expression in aCLL, CLL and MCL, and lower expression in MZL Itgam and SMZL, probably due to clonality in the intermediate stage of the disease. Despite CD43 not being a relevant marker for the differential diagnosis of MCL and MZL, caution should be taken in the interpretation of these data with respect to the differential diagnosis of MCL versus CD5-positive MZL. One MCL case (16.0%) had a HBX 19818 low expression of this marker much like MZL and one MZL case (5.8%) showed intermediate expression similar to that seen in MCL. CD52 is usually a cell surface glycoprotein whose function is usually poorly comprehended and is expressed in lymphocytes, monocytes, macrophages and a few dendritic cells.21 Its expression has been described in several MBCN and positivity for this marker involves specific treatments for diseases such as CLL and LPL.3, 22, 23 Furthermore, soluble CD52 has been identified as a marker of disease activity in CLL.24 This study identified the expression of CD52 in 100% of analyzed cases. Although these results seem to be in contrast with those explained by other studies, such as Rodig et al. who reported negativity for some diseases such as Burkitt lymphoma and DLBCL, 3 the lowest MFIs in the samples of the present study were exactly for Burkitt lymphoma and DLBCL. Chuang et al. analyzed MCL cases and recognized that only 60% of cases were positive for CD52, but the difference in HBX 19818 the immunohistochemical technique used may explain the distinct results.25 Since fluorescence intensity measures are important determinants in the analysis of leukemias and lymphomas,26 reliable methods for measuring MFI are important for the correct data interpretation, and, consequently, correct classification of hematological malignancies. For this reason, terms such as poor and strong are useful, HBX 19818 but, as Henderson et al. suggested, perhaps quantitative values could be used in order to further explore the information provided.27 There are numerous variables involved in the quantitative determination of fluorescence intensity, some related to the specificity in the chosen MoAb, sample type, anticoagulant employed, autofluorescence, type of fixation, cytometer compensation and unit of measurement used to statement the data, among others. Even when all these variables are well controlled, some caution in interpreting the data should be taken, but given the increasing universal standardization in the field.