Immunological evidence of monoclonal gammopathy in North India: a hospital based study

Kalpana Singh¹, Bhawna Singh², Sarika Arora², Alpana Saxena<sup>1

1</sup>Department of Biochemistry, Maulana Azad Medical College and LN Hospital, New Delhi, India; ²Department of Biochemistry, GB Pant Hospital, New Delhi, India

Background: Monoclonal gammopathy of unknown significance (MGUS) is a condition in which a paraprotein is found in the blood during standard laboratory tests. It is age-related and characterized by accumulation of bone marrow plasma cells derived from a single abnormal clone. The aim of this study was to investigate the pattern of MGUS in North Indian urban population.

Methods: Serum and urine samples were collected from 320 suspected cases of gammopathy, were analyzed by sensitive immunological technique based protein electrophoresis followed by immunofixation for detection and type of monoclonal/polyclonal gammopathies. Twenty-five healthy subjects were included as controls.

Results: Gammopathies were observed in 38 (11.88%) patients. Out of these 7.5% were ¬monoclonal and 4.3% were polyclonal. Overall age of presentation of these monoclonal ¬gammopathies in both sexes was between 21 and 76 years. Gender-related ratio (men:women) for these gammopathies was 1:1.18. Predominant heavy chain isotype was IgG (62.5%) followed by IgA (37.5%). Among light chains, kappa (κ) and lambda (λ) chains appeared in 91.6% and 8.4% gammopathies respectively. Paraprotein fractions obtained were IgGκ (58.3%), IgGλ (4.16%), IgAκ (33.3%), and IgAλ (4.16%) with 25% samples being positive for Bence Jones proteinuria.

Conclusions: Clinical laboratories play an important role in confirming the immunological diagnosis of gammopathies. Determination of nature of paraproteinemia and its associated diseases calls for more extensive studies in India.

Keywords: monoclonal gammopathy, immunoelectrophoresis, multiple myeloma, bence jones protein, immunoglobulins