Gamma-heavy chain monoclonal gammopathy with undetermined significance (MGUS)

Abstract

Gamma-heavy chain disease (γ-HCD) is a rare B-cell tumor producing truncated IgG lacking the light chain. The clinical features of γ-HCD are heterogeneous, similar to lymphoplasmacytic lymphoma, and most patients have generalized and progressive disease. In some γ-HCD patients, autoimmune diseases are associated. Thus, γ-HCD as a restricted or indolent disease is exceptional. A 66-year-old male was referred to our hospital because of subungual hemorrhage at the bilateral halluces. Physical and laboratory examination results were nonspecific, and the hemorrhage was revealed to be traumatic. However, serum electrophoresis demonstrated a small M-peak, which was monoclonal IgG-Fc without the corresponding light chain on immunofixation and immunoelectrophoresis. Bone marrow aspirate demonstrated a small number of lymphoplasmacytic cells that were positive for CD19, CD38, CD138, and cyIgG, but negative for cyκ- and -λ light chains on flow cytometry. A diagnosis of γ-HCD was made. Chest and abdominal CT demonstrated neither hepatosplenomegaly, lymphadenopathy, nor bone lytic lesions. The serum concentrations of IgG and M-peak configuration have remained relatively unchanged for nearly 3 years. Therefore, this γ-HCD may correspond to a rare form of monoclonal gammopathy with undetermined significance.

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

“…Indeed, in another γ-HCD case, we were able to detect cyIgG using the polyvalent anti-IgG antibody but not the monoclonal antibody in FCM analysis. 26 On immunohistochemistry of a necropsy specimen from the present patient, we successfully detected IgG in abnormal lymphocytes because we used the polyvalent anti-IgG antibody. The presence of many IgGpositive tumor cells in the necropsied bone marrow may reflect cumulative tumor infiltration over 2 months because the marrow aspirate on admission only included a small number of abnormal cells on morphological and FCM evaluation.…”

Gamma-heavy chain disease

“…Také Zushi et al [13] studovali pacienta, který byl hospitalizován kvůli Účinnost u celé řady méně častých mutací 1 1 Účinnost u mozkových metastáz 8 Pozitivní vliv na příznaky nádorového onemocnění a kvalitu života 9,10 Vyšší účinnost oproti ERLOTINIBU u skvamózního karcinomu 7 * Bez omezení následných možností léčby [11][12][13] Delší PFS oproti chemoterapii v 1. linii léčby 4,14 Delší OS u del19 oproti chemoterapii 4,12,[14][15][16] Ireverzibilní blokáda receptorů rodiny ErbB prokázaná ve 2 globálních srovnávacích studiích 4,6,11,12,14,[17][18][19][20] Vyšší účinnost oproti ge tinibu 6 **…”