Gamma heavy chain disease (γ-HCD) as iatrogenic immunodeficiency- associated lymphoproliferative disorder: Possible emergent subtype of rheumatoid arthritis-associated γ-HCD.

Gamma heavy chain disease (γ-HCD) is a rare B-cell neoplasm that produces a truncated immunoglobulin γ-heavy chain lacking the light chain. The clinical features of γ-HCD are heterogeneous, resembling different types of B-cell lymphomas. Although rheumatoid arthritis (RA) is one of the common underlying diseases of γ-HCD, the therapeutic modality for RA has changed greatly in recent years; therefore, γ-HCD as iatrogenic immunodeficiency-associated lymphoproliferative disorder (LPD) should be taken into consideration. Here, we report such a γ-HCD case. A 69-year-old female was admitted because of fever, multiple lymph node swelling in the abdominal cavity, and peritoneal effusion. She had been treated using methotrexate for RA for 14 years, and using infliximab and adalimumab for Crohn's disease for one year. The serum concentration of IgG was 3,525 mg/dL, which was revealed to be monoclonal IgG lacking the light chain by rocket immunoselection assay. CD19+/CD20-/smκ-/smλ- large abnormal lymphocytes were observed in the peritoneal fluid, which were demonstrated to be clonal B-cells by PCR examination. Discontinuation of methotrexate did not improve her condition and she died of pneumonia. Many abnormal lymphocytes positive for IgG and EBER but negative for the light chain were found on immunohistological examination of necropsy specimens from the spleen and bone marrow.

[Simultaneous presence of macroamylase and macrolipase in a patient with celiac disease].

Celiac disease is a permanent intolerance to ingested gluten that results in immunologically mediated inflammatory damage of the small intestinal mucosa. Here we report the case of a patient with Celiac disease demonstrating simultaneous macroamylasemia and macrolipasemia. The patient showed persistently elevated levels of serum amylase and lipase. Amylase and lipase in normal serum were eluted from a Superdex-200 column after the 4S protein. These enzymes in the serum from this patient were eluted in the 19S protein. This finding indicated that these enzymes from this patient had a molecular weight greater than that of normal amylase and lipase. Immunoprecipitation assay showed that amylase was bound to polyclonal IgG and IgA, whereas lipase was bound to polyclonal IgA. To our knowledge, the simultaneous presence of macroamylase and macrolipase in the same patient has been previously reported in only four cases. Interestingly, two of those patients had Celiac disease. If macroamylase and macrolipase are present, the possibility of Celiac disease should be considered.

[Immunochemical properties of free mu-chain protein in a patient with mu-heavy chain disease].

We report a case of mu-heavy chain disease. A 56-year-old woman presented with anemia and hemorrhagic diathesis. The serum of the patient was found to have free mu-heavy chain. The patient also had a kappa type-Bence Jones protein in serum and urine. Immunoelectrophoresis showed an abnormal precipitin line in the alpha 2-globulin region which reacted with antiserum to mu-chain but not with antiserum for light chains. The molecular weight of the monomer of the patient's mu-heavy chain protein was approximately 67,000 daltons less than that of the normal mu-heavy chain protein.