Search PubMed⌕ Search

Biomedical subjects

G Merlini

Publications and source records attributed to G Merlini.

126 records · Page 7Linked to original sources

Neuropathies associated with monoclonal gammapathies.

There is increasing evidence that monoclonal proteins are implicated in the development of peripheral neuropathy. Approximately ten percent of patients with peripheral neuropathy of unknown cause have a monoclonal protein and this rate is significantly higher than prevalence rates of monoclonal protein in comparable segments of the general population. Extensive clinical, electrophysiological and immunopathological evidences indicate that peripheral neuropathy associated with monoclonal protein are heterogeneous, including: 1. the demyelinating, predominantly sensory neuropathies associated with anti-MAG antibodies; 2. the axonal, sensory neuropathies associated with anti-sulfatide and anti-chondroitin sulfate antibodies; 3. the motor neuropathies associated with anti-GM1 antibodies. Patients with chronic polyneuropathies should be evaluated for underlying plasma cell dyscrasia.

Adult↗

Diagnostic approach to and follow-up of difficult cases of AL amyloidosis.

BACKGROUND: Routine electrophoretic analysis fails to detect a monoclonal component (MC) in a considerable portion of AL amyloidosis patients. We investigated whether the combination of immunofixation (IF) on agarose gel electrophoresis and bone marrow plasma cell (BMPC) light chain kappa/lambda ratio analysis could contribute to diagnosis in these cases. The possible use of the BMPC kappa/lambda ratio in monitoring the clone was also investigated. METHODS: We performed BMPC kappa/lambda ratio analysis and IF of serum and urine in 16 selected patients with no detectable MC at routine analysis, despite clinical features suggestive of primary amyloidosis. An anti-idiotypic monoclonal antibody specific for the amyloidogenic immunoglobulin and the BMPC kappa/lambda ratio were used to monitor the clone in a patient who underwent autologous peripheral blood stem cell transplantation. RESULTS: Abnormal kappa/lambda ratios were found in 14 (sensitivity 87.5%), and a MC in 12 (sensitivity 75%). Combination of the two analyses confirmed diagnosis in all cases. In one patient changes in the size of the clone, monitored on serial bone marrow aspirates by an anti-idiotypic antibody, paralleled variations of the kappa/lambda ratio. CONCLUSIONS: This study demonstrates that the combined use of IF and the BMPC kappa/lambda ratio is extremely powerful in AL amyloidosis. In addition, the BMPC kappa/lambda ratio should be considered for monitoring the amyloidogenic clone when serum or urine MC is not quantifiable.

Adult↗

Familial AL-amyloidosis in three Italian siblings.

BACKGROUND AND METHODS: Familial occurrence of immunoglobulin-related (AL) amyloidosis has occasionally been reported. In this work we describe the concomitance of systemic amyloidosis and monoclonal gammopathy (one case of Waldenström's macroglobulinemia and two cases without multiple myeloma or related diseases) in three Italian siblings, two males and one female. RESULTS AND CONCLUSIONS: All of them showed a common pattern of polyneuropathy to different degrees; two presented a sicca syndrome and one also suffered from nephropathy. Two of them showed the same HLA typing with the same light chain type (k), but had different presenting symptoms. Polyneuropathy and a history of peptic disease in two cases was suggestive of type III familial amyloidotic polyneuropathy (FAP) occurring in the setting of a familial monoclonal component. However, immunohistochemical studies on different tissue specimens using anti-apolipoprotein A1 and anti-transthyretin antibodies were negative. Further screening of DNA samples for transthyretin (TTR) gene mutations was also negative. Clinical and laboratory investigations ruled out reactive or senile amyloidosis and immunohistochemical studies with anti-light chain antibodies on amyloidotic tissue specimens were positive. As a consequence, this family represents a new case of familial AL-amyloidosis.

Aged↗

Reduced taste perception in AL amyloidosis. A frequently unnoticed sensory impairment.

BACKGROUND: Sporadic observations suggest a possible taste impairment in AL amyloidosis, but the frequency and intensity of this sensory anomaly are not known. MATERIALS AND METHODS: We submitted 21 AL amyloidotic patients, drawn from subjects referred to the Amyloidosis Study Center of the Department of Internal Medicine and Medical Therapy, University of Pavia, to suprathreshold scaling analysis. RESULTS: Taste acuity was reduced in most of them. Every taste showed independent behavior, and 90% of these patients were hypogeusic. True ageusia for one or two tastes was observed in 35% of patients. No patient was aware of reduced taste acuity. Macroglossia did not seem to play a prominent role in dulling tastes. CONCLUSIONS: Impairment of taste perception suggests that gustative neuropathy is a frequently unnoticed expression of sensory involvement in AL amyloidosis.

Adult↗

Immunochemical characterization of the cryoglobulins: pathophysiologic implications.

Immunochemical study of the cryoglobulins has produced a classification of three main types which present clinical correlates. With the current standard immunofixation technique the vast majority of cryoglobulins are presently classified as type II. High-resolution immunoelectrophoretic techniques (immunoblotting and two-dimensional polyacrylamide gel electrophoresis) have helped to identify new sub-types whose clinical relevance is as yet undetermined. Nevertheless, these sensitive techniques could contribute to elucidate the various stages in the natural history of HCV-related cryoglobulins, from possible earlier HCV-antigen-driven polyclonal B cell proliferation, to autonomous monoclonal benign, to malignant B cell proliferation.

Cryoglobulins↗