Abstract
Beta-2-microglobulin (B2M) is a cell surface protein on many somatic cells including T and B lymphocytes and macrophages as a subunit of class I major histocompatibilty complex (MHC). Soluble interleukin-2 receptor (sIL-2R) is a T cell derived cytokine that induce proliferation of activated T cells, participates in differentiation of B cells and modulates macrophage function and phenotype. Both serum B2M and sIL-2R levels reflect immune-system activation and are elevated in patients with HIV-NHL-DLBCL. Combined detection of B2M and sIL-2R can be used to predict treatment response or failure in patients with aggressive HIV-NHL-DLBCL. When highly active antiretroviral therapy (HAART) chemotherapy is administered to refractoriness of elevated B2M and sIL-2R serum levels may be seen in HIV-NHL-DLBCL poor responders or failures. As sIL-2R levels decrease, B2M levels remain elevated in early stage HIV-NHL-DLBCL. Treatment of these patients with CHOP-rituximab and HAART both markers decrease. However, in late stage disease (stage III-IV, HIV-NHL-DLBCL based on DLBCL), B2M and sIL-2R remain significantly elevated and prognosis poor even after immune restoration of CD4+ T cell count and HIVRNA viral load approach normal.
CASE: We present one of several cases - a 38 year old HIV positive male with DLBCL of his sinus turbinates, had turbinectomy surgery with sIL-2R level of 617 U/mL (5,460.226 pg/ml) postop which gradually increased to 27,673.95 pg/ml in less than six months. The B2M level while on HAART decreased from 18.8 mg/L to 4.4 mg/L. His LDH, CRP, and GGT levels were elevated but the CD4+ T cell count was 26% and his HIVRNA viral load became undetectable. After CHOP-rituximab therapy sIL-2R decreased to 10,806 pg/ml from 27,674 pg/ml but slowly rose to 39,975.25 pg/ml and B2M increased to 19 mg/L. The CD19+ B cell count was zero and a CD4/CD8 ratio improve to 0.546.
CONCLUSION: B2M and sIL-2R serum level measurements provides data that when used together may offer a better management approach to these HIV-NHL-DLBCL patients. B2M and sIL-2R elevated refractory levels correlates with tumour burden and predicts poor prognosis in aggressive HIV-NHL-DLBCL.
Serum levels of Beta-2 microglobulin and interleukin-6 in HIV positive individuals and their correlation with CD-4 cell count
