Epidemiology of monoclonal gammopathy in Morocco – A hospital‐based study

Abstract

Background Monoclonal gammopathies are a group of disorders associated with clonal proliferation of plasma cells that produces a monoclonal protein. Aims The main objective of this study was to describe the epidemiological and immunochemical characteristics of monoclonal gammopathies diagnosed during 19 years in a Moroccan teaching hospital. Materials and Results This retrospective study enrolled 443 Moroccan patients with monoclonal gammopathy, patients meeting the inclusion and exclusion criteria in at the biochemistry department of Military Hospital in Rabat, the capital of Morocco, from January 2000 to August 2019. Of the 443 enrolled patients, 320 (72.23%) were men and 123 (27.77%) were women. All patients were of Caucasian origin, from 12 Moroccan regions. The patient's samples were collected and subjected to serum protein electrophoresis and serum immunofixation electrophoresis to further characterize the monoclonal protein. The mean ± SD age of the 443 participants was 62.24 ± 13.14 years. Reasons for being admitted to the hospital were as follows, bone pain (41.60%), renal failure (19.08%), alteration of the general condition (12.21%), and anemia (10.69). Plasma cell proliferative disorders in our study were as follows, multiple myeloma (MM) (45.65%), Monoclonal gammopathies of undetermined significance (MGUS) (39.05%), Waldenstrom's macroglobulinemia (5.58%), Lymphoma (2.27% + 1.2%), Chronic Lymphocytic Leukemia (2.48%), Plasma cell leukemia (1.86%), Plasmacytoma (0.62%), POEMS syndrome (0.41%), and Amyloidosis (0.84%). The most frequent isotypes in MM were the IgGκ (62) 36.5%, IgGλ (52) 30.6%, IgAκ (27) 15.9%, and the IgAλ (19) 11.2%. It is also worth noting that Free light chain MM represents 20% of all cases of MM. Conclusions We found that monoclonal gammopathies are age‐related and affects men more than women, also the results of this study point to the delayed diagnosis of monoclonal gammopathies, since most of our patients were diagnosed at the MM stage. The most frequent isotypes were the IgGκ and IgGλ in MM and MGUS, in Waldenström macroglobulinemia were IgMκ and IgMλ and the oligoclonal profile represented only 3.70%.

A Unique Case of Cellulitis Secondary to Mycobacterium chelonae in a Patient With Monoclonal Gammopathy of Undetermined Significance

“…A two to three-fold increase in the relative risk for viral and bacterial infections has been documented in patients with MGUS [11]. It is known that both humoral and cellular immunity are affected [11], with impairment of antibody production, function of T-cells, natural killer (NK) cells, and dendritic cells [10,11]. This immune dysregulation likely made our patient susceptible to prolonged skin infection with an uncommon pathogen.…”

“…Monoclonal Gammopathy of Undetermined Significance is considered an early stage of multiple myeloma (MM), where the production of monoclonal protein is present without systemic effects. It is estimated that 1% of MGUS progress to MM yearly [10]. Patients with MGUS also have a higher rate of renal disease, ischemic heart disease, peripheral neuropathy, and infections compared to those without MGUS [11].…”

Non-Secretory Multiple Myeloma: A New Observation and Review of the Literature

“…Migkou et al [ 2 ] reported in their work on a total of 852 patients, 100 (12%) cases identified as oligo-secretory/non-secretory of which 20 (2.3%) were true non-secretors. A Moroccan study of 443 MM cases identified five patients with NSMM (2.26%) [ 3 ].…”

“…The mean age was less than 65 years. Other studies [ 3 , 4 ] also concluded that NSMM patients were younger, with an average age of 57.80 years [ 3 ] and 56 years [ 4 ], respectively. In the present study, the patient was 53 years old, in line with cases reported in the literature.…”

“…In 2-3% of MM patients, no identifiable monoclonal immunoglobulin can be detected in biological matrices [ 2 ]. This type of multiple myeloma, known as non-secretory multiple myeloma (NSMM), is defined by the presence of more than 10% clonal plasma cells in the bone marrow, or biopsy-proven plasmacytosis, evidence of organ damage related to the underlying plasma cell proliferation, particularly hypercalcemia, renal failure, anemia or bone lesions, and the absence of serum and urine monoclonal protein on electrophoresis and immunofixation [ 3 , 4 ]. Given its low frequency, few data are available on the diagnosis, clinical course and response to treatment of this type of MM.…”