TY - JOUR
T1 - Hematologic characteristics of proliferative glomerulonephritides with nonorganized monoclonal immunoglobulin deposits
AU - Bhutani, Gauri
AU - Nasr, Samih H.
AU - Said, Samar M.
AU - Sethi, Sanjeev
AU - Fervenza, Fernando C.
AU - Morice, William G.
AU - Kurtin, Paul J.
AU - Buadi, Francis K.
AU - Dingli, David
AU - Dispenzieri, Angela
AU - Gertz, Morie A.
AU - Lacy, Martha Q.
AU - Kapoor, Prashant
AU - Kumar, Shaji
AU - Kyle, Robert A.
AU - Rajkumar, S. Vincent
AU - Leung, Nelson
N1 - Publisher Copyright:
© 2015 Mayo Foundation for Medical Education and Research.
PY - 2015/5/1
Y1 - 2015/5/1
N2 - Objective To study the hematologic characteristics of proliferative glomerulonephritides (GNs) from nonorganized glomerular monoclonal immunoglobulin (MIg) deposition (MIPG). Patients and Methods The pathology database at Mayo Clinic (Rochester, Minnesota) was used to find patients with MIPG who underwent a kidney biopsy between January 1, 2008, and December 31, 2013. Retrospective medical record review was conducted in the identified cohort (N=60). Results The median patient age was 56 years (interquartile range, 47-62 years) and the estimated glomerular filtration rate was 36 mL/min/1.73 m2 (interquartile range, 22-52 mL/min/1.73 m2). Most patients had IgG MIg deposits (90%; 54 of 60) and a membranoproliferative pattern (48%; 29 of 60). A circulating nephropathic MIg was detected by serum immunofixation (SIFE+) in 20% (12 of 59) and by abnormal serum free light chain ratio (sFLCR+) in 21% (12 of 56). The subsets of SIFE+ and sFLCR+ incompletely overlapped. The nephropathic clone was found by bone marrow testing (BM+) in 25% (10 of 40; 6 plasma cell clones [5 IgG; 1 IgA], 3 chronic lymphocytic leukemia [all IgG], and 1 lymphoplasmacytic clone [IgM]). The clone detection rate was significantly higher in patients with SIFE+ (P<.001) and in those with SIFE+ and/or sFLCR+ (P<.001). Patients with SIFE+ and BM+ frequently had IgG1-restricted MIg deposits on renal biopsy immunofluorescence (P=.005). Most BM+ patients required flow cytometry and immunohistochemical analysis of the marrow specimen for accurate diagnosis. Conclusion Undetectable circulating nephropathic MIg and pathologic clones characterize most MIPG. Immunoglobulin isotype may predict detectability of MIg and clone by currently available technology. Bone marrow evaluation, including flow cytometry and immunohistochemical analysis, should be performed for SIFE+ and/or sFLCR+. More sensitive clone-identifying techniques in the marrow and extramedullary tissue are needed when SIFE and sFLCR test negative.
AB - Objective To study the hematologic characteristics of proliferative glomerulonephritides (GNs) from nonorganized glomerular monoclonal immunoglobulin (MIg) deposition (MIPG). Patients and Methods The pathology database at Mayo Clinic (Rochester, Minnesota) was used to find patients with MIPG who underwent a kidney biopsy between January 1, 2008, and December 31, 2013. Retrospective medical record review was conducted in the identified cohort (N=60). Results The median patient age was 56 years (interquartile range, 47-62 years) and the estimated glomerular filtration rate was 36 mL/min/1.73 m2 (interquartile range, 22-52 mL/min/1.73 m2). Most patients had IgG MIg deposits (90%; 54 of 60) and a membranoproliferative pattern (48%; 29 of 60). A circulating nephropathic MIg was detected by serum immunofixation (SIFE+) in 20% (12 of 59) and by abnormal serum free light chain ratio (sFLCR+) in 21% (12 of 56). The subsets of SIFE+ and sFLCR+ incompletely overlapped. The nephropathic clone was found by bone marrow testing (BM+) in 25% (10 of 40; 6 plasma cell clones [5 IgG; 1 IgA], 3 chronic lymphocytic leukemia [all IgG], and 1 lymphoplasmacytic clone [IgM]). The clone detection rate was significantly higher in patients with SIFE+ (P<.001) and in those with SIFE+ and/or sFLCR+ (P<.001). Patients with SIFE+ and BM+ frequently had IgG1-restricted MIg deposits on renal biopsy immunofluorescence (P=.005). Most BM+ patients required flow cytometry and immunohistochemical analysis of the marrow specimen for accurate diagnosis. Conclusion Undetectable circulating nephropathic MIg and pathologic clones characterize most MIPG. Immunoglobulin isotype may predict detectability of MIg and clone by currently available technology. Bone marrow evaluation, including flow cytometry and immunohistochemical analysis, should be performed for SIFE+ and/or sFLCR+. More sensitive clone-identifying techniques in the marrow and extramedullary tissue are needed when SIFE and sFLCR test negative.
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U2 - 10.1016/j.mayocp.2015.01.024
DO - 10.1016/j.mayocp.2015.01.024
M3 - Article
C2 - 25939936
AN - SCOPUS:84929469048
SN - 0025-6196
VL - 90
SP - 587
EP - 596
JO - Mayo Clinic proceedings
JF - Mayo Clinic proceedings
IS - 5
ER -