Outcomes of patients with AL amyloidosis and low serum free light chain levels at diagnosis. (3rd July 2018)

• Record Type: Journal Article
• Authors: Nguyen, Vina P.; Rosenberg, Allison; Mendelson, Lisa M.; Comenzo, Raymond L.; Varga, Cindy; Sanchorawala, Vaishali
• Is Part Of: Amyloid. Volume 25:Number 3(2018)
• Page Start: 156
• Page End: 159
• Publication Date: 2018-07-03
• Subjects: AL amyloidosis -- stem cell transplantation -- survival -- immunoglobulin light chain -- haematologic response; Amyloidosis -- Periodicals; 616.3995
• DOI: 10.1080/13506129.2018.1490261
• Languages: English
• ISSNs: 1350-6129

Abstract

Abstract: Serum free light chains (sFLC) are independent prognostic markers of disease in light chain (AL) amyloidosis, and are used in the haematologic response criteria for treatment. However, up to 20% of patients have low sFLCs at diagnosis, with a difference between involved and uninvolved free light chains (dFLC) of less than 50 mg/L, making responses to treatment difficult to evaluate. In order to characterize this distinct subgroup of patients, we retrospectively analyzed 123 AL amyloidosis patients with dFLC <50 mg/L who were diagnosed between 2002 and 2013. The majority ( n = 117) were treated for their AL amyloidosis, with over half ( n = 68) receiving high-dose melphalan and autologous stem cell transplantation as first-line therapy. Overall they had a prolonged median survival of 9.2 years with less cardiac involvement (30%) and more renal involvement (76%). We also evaluated the newly proposed low dFLC partial response (PR) criteria, defined as a dFLC <10 mg/L if the initial dFLC 20–50 mg/L. The 14 patients with low dFLC PR had improved survival and organ responses compared with patients with no haematologic response. However, one-third of patients ( n = 41) had an initial dFLC <20 mg/L so could not be evaluated. More sensitive methods of monitoring response to treatment for this subgroup population are still needed.