Abstract: SA-PO185
Tubulointerstitial Lesions Associated with Monoclonal Gammopathies of Renal Significance
Session Information
- Onco-Nephrology: Clinical
November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Onco-Nephrology
- 1500 Onco-Nephrology
Authors
- Santos, Afonso, Hospital Fernando Fonseca, Lisbon, Portugal
- Gaspar, Ana, Hospital Fernando Fonseca, Lisbon, Portugal
- Lima, Anna, Hospital Fernando Fonseca, Lisbon, Portugal
- Theias Manso, Rita, Hospital Fernando Fonseca, Lisbon, Portugal
- Soto, Karina, Hospital Fernando Fonseca, Lisbon, Portugal
Background
Monoclonal gammopathy of Renal Significance (MGRS) is not a benign monoclonal disorder, neither a determined disease; abridge many kidney pathologies related to low proliferative small B-cell clone, being associated with kidney-end-organ damage, therefore requiring treatment.
Herein we present a series of 11 patients who had monoclonal gammopathy (MG) and performed kidney biopsy, showing tubulointerstitial MGRS.
Methods
A retrospective analysis was performed. Patients with systemic lupus erythematous, HIV infection or Hemolytic Uremic Syndrome (with TMA) were excluded. Demographic, clinical, pathological and treatment data were collected from the admission to last follow-up.
MGRS were defined according to the last categorization by the International Kidney and Monoclonal Gammopathy Research Group. Proximal Tubulopathies (PT) were classified as (a) PT without cytoplasmic inclusions; (b) PT associated with interstitial inflammatory reactions; (c) LCPT with crystals, (d) Crystal storing histiocytosis and (e) miscellaneous.
Results
From a total of 329 patients who performed kidney biopsy, 29 patients were initially excluded. Were also excluded 258 biopsied patients who did not had confirmed MG diagnosis, leading to a total of 40 patients. Of them, 14 had MM, 4SMM, 1WM, 2SWM and 15 MGUS, 2 amyloidosis, 1CLL and 1NHL indolent. Of all of them, 26 had MGRS criteria (65%). In the MM group most patients presented cast nephropathy (71%, n=10). In MGRS group most patients had glomerular lesions (n=17, 65%), while 11 (42%) had tubular lesions (2 patient with both lesions). The majority of these had (b) lesions (n=7, 64%); one patient had Fanconi Syndrome with lambda deposit crystals (c); one with (a) and cell vacuolization; one with (d) and one patient had AL tubular amyloidosis (e). Patients with MGRS had 66±2,9yo, most admitted with AKI. Median SCr of 2,5 mg/dL(IQR 1,61–5,55); proteinuria 2,52 g/d (IQR 1,41-6,49); ACR 0,5 g/g (IQR 0,14-2,58) and mean hemoglobin 12,1±2,84g/dL at admission.
Conclusion
The histopathological features of monoclonal gammopathies are broad, reflected in the proposed MGRS spectrum of renal lesions. In our series with monoclonal gammopathy patients tubular lesions were diverse, but none patient had been found with crystal-storing histiocytosis, but tubular deposits were found in immunofluorescence and electronic microscopy.