Background:
One of the devastating consequences of
monoclonal gammopathies is the development of
end-stage kidney disease, which can be prevented with an
early diagnosis. Renal involvement can be
secondary to saturation of
paraproteins with intratubular precipitation or the glomerular deposition of
paraproteins with
secondary inflammation and destruction. These conditions can also be associated with
monoclonal gammopathies that do not meet hematological
treatment criteria, called
monoclonal gammopathies of renal significance (MGRS).
Aim:
To
report a retrospective
analysis of
patients who underwent a renal
biopsy and whose final
diagnosis was a form of
monoclonal gammopathy. Material and
Methods:
We reviewed the clinical and
laboratory features and response to
treatment of 22
patients aged 63 ± 12 years (55%
women) with a pathological
diagnosis of a nephropathy associated with
paraproteinemia.
Results:
The most common hematological
diagnosis was
amyloidosis in 50% of
patients, followed by cast nephropathy. The predominant clinical presentations were
proteinuria (without
nephrotic syndrome) and nephritic
syndrome. Classic criteria such as
erythrocyte sedimentation rate > 100 mm/h and
protein-
albumin gap were unusual.
Serum light chain quantification was the test with the best yield to detect
paraproteins.
Conclusions:
In this group of
patients,
light chains tend to
affect the
kidney more commonly than heavy chains. The
prognosis of
multiple myeloma is much worse than MGRS.