title: Diagnostic Utility of PAX5 in Hodgkin and Non-Hodgkin Lymphoma: A Study from Northern India.
abstract: BACKGROUND
  PAX5 is an immunomarker of B-cell origin and useful in the diagnosis of lymphoma. There is hardly any study on PAX5 expression in Indian patients with lymphoma.
  
  
  OBJECTIVE
  To evaluate the diagnostic utility of PAX5 as an adjunct immunohistochemical marker in the diagnosis of Hodgkin Lymphoma (HL) and Non-Hodgkin Lymphoma (NHL).
  
  
  METHODS
  Immunohistochemistry was performed against CD20, CD3, CD15, CD30, and PAX5 on formalin fixed paraffin embedded tissue of 71 cases of lymphoma and CD20, CD3 and PAX5 in control samples of reactive lymph nodes. Frequency, mean values, and percentage were calculated. Fisher's-exact test and test for analysis of variance were applied.
  
  
  RESULTS
  For 24 cases of HL and 47 cases of NHL, the mean age of patients was 17.6±14.8 years and 44.1±21.6 years, respectively. The male: female ratio for both HL and NHL were 1.7:1. Among NHL cases, the numbers of B-cell and T-cell types were 39/47 (83%) and 8/47 (17%), respectively. In comparison to control samples, PAX5+ expression was seen in 23/24 (95.8%) cases of HL (p=1.000) and 32/39 (82%) cases of B-NHL (p=0.0834). All the cases of T-NHL showed negative expression of PAX5 (p<0.0001). Analysis of variance between NHL, HL and control samples was statistically significant (p<0.0001).
  
  
  CONCLUSIONS
  PAX5 staining between control samples and cases of classical HL and B-NHL was statistically not significant, whereas, statistically significant difference was observed with T-NHL. Thus, PAX5 may be used as an adjunct marker in the diagnosis of classical HL and B-NHL.
authors.affiliation: Junior Resident, Department of Pathology, Institute of Medical Sciences, Banaras Hindu University , Varanasi, Uttar Pradesh, India .
authors.forename: Nidhi
authors.initials: N
authors.lastname: Johri
authors.affiliation: Assistant Professor, Department of Pathology, Institute of Medical Sciences, Banaras Hindu University , Varanasi, Uttar Pradesh, India .
authors.forename: Shashikant C U
authors.initials: SC
authors.lastname: Patne
authors.affiliation: Associate Professor and Head, Department of Surgical Oncology, Institute of Medical Sciences, Banaras Hindu University , Varanasi, Uttar Pradesh, India .
authors.forename: Mallika
authors.initials: M
authors.lastname: Tewari
authors.affiliation: Professor, Department of Pathology, Institute of Medical Sciences, Banaras Hindu University , Varanasi, Uttar Pradesh, India .
authors.forename: Mohan
authors.initials: M
authors.lastname: Kumar
keywords: B-cell specific activator protein; Hodgkin/Reed-Sternberg cell; Immunohistochemistry; Lymphoproliferative disorder