Increased IL-6 detection in adult and pediatric lymphoid tissue harboring parvovirus B19

Parvovirus B19 (B19V) is a common pathogenic virus infecting humans. Previous studies have shown evidence of B19V infection in patients with non-Hodgkin's lymphoma (NHL) and Hodgkin's lymphoma using ELISA and PCR on serum specimens. B19V nonstructural protein is known to alter the expression of cellular factors including interleukin-6 (IL-6), which can increase the risk for and worsen the prognosis of lymphomas.

The objective of this study was to detect B19V capsid protein and IL-6 expression in normal and malignant lymphoid tissue, as well as any correlation between the two.

IHCs for B19V capsid protein, IL-6, and B19V co-receptors P-antigen and α5β1 integrin were performed on a tissue array containing 70 duplicated pediatric and adult lymphoma tissues and 5 duplicated benign lymph node sections. Cases were identified as normal, B-cell NHL, diffuse large B-cell NHL, Hodgkin's lymphoma, extranodal NK/T cell lymphoma, anaplastic large cell lymphoma, or mantle cell lymphoma. IL-6 and B19V capsid staining were quantified using a positive pixel count algorithm, and P-antigen and α5β1 staining using a membrane quantification algorithm.

B19V capsid protein was detected in both benign and malignant lymphoid tissue. The Spearman rank correlation coefficient analysis was performed to determine the relationship between the level of positivity for B19V and IL-6 staining, yielding an overall correlation coefficient of 0.679 (p-value<0.0001).

Our results show a moderate correlation between the levels of positive B19V and IL-6 staining by IHC, indicating a possible role for B19V in the pathogenesis of lymphomas.