A clinically relevant monoclonal gammopathy in pediatric age

finding in pediatrics. Only viral infections, transplantation and immunosuppressive therapy may induce B-cell proliferation leading to monoclonal component (MC) appearance in serum. Here we describe a case of clinically relevant MG in pediatric age. Methods: After receiving a request for a serum protein electrophoresis test (SPE) in a 12 years-old boy, information on the patient was collected. He was affected by ileocolonic Crohn’s disease from April 2010, treated with nutritional therapy, prednisone and azathioprine. In February 2011, after a disease relapse, therapy with antibodies against tumour necrosis factor- (infliximab and, later, adalimumab) replaced azathioprine. In November 2011 the boy was hospitalized for a further severe relapse. He was treated with corticosteroids in combination with adalimumab at increased dosage, achieving disease remission. A biochemical evaluation on the patient in remission was lastly performed in May 2012. SPE and MC immunotyping by immunosubtraction technique were carried out using capillary zone electrophoresis (Sebia Capillarys), whereas agarose gel immunofixation (IFE) of serum and urine was performed on Hydrasys (Sebia). Results: We retrieved in our LIS a SPE first performed on April 2010 showing a 4.7 g/L MC immunotyped as IgG . On November 2011 at SPE 3 MCs (concentrations: 3.7, 2.8 and 3.8 g/L, respectively) were detected and typed as IgA , IgM and IgG by IFE. A -type Bence Jones protein (BJP) was also detected in urine. Bone marrow examination was carried out to exclude lymphoid/myeloid malignancies (LMM) resulting in a negative pattern. At the evaluation performed on May 2012 only an IgG MC (4.5 g/L) was found in patient’s serum, the -type BJP still persisting. Conclusions: Crohn’s disease in adults, particularly when treated by immunosuppressive drugs, can be associated with MG and an increased risk of developing LMM. At our best knowledge, no report of such association has been previously reported in pediatrics. This case illustrates a specific situation in which SPE execution in the young is recommended to prevent the risk of silent LMM development. It also shows that highly sensitive techniques are needed to detect small, but clinically relevant MCs.