ABNORMAL PLASMA COMPONENTS AND THEIR SIGNIFICANCE IN DISEASE*

TWO MAJOR TYPES OF NORMAL 7S gamma-GLOBULIN

Normal 7S human gamma-globulin was found to contain two fundamental antigenic groups of molecules. The group 1 molecules of normal gammaglobulin correspond antigenically to group 1 multiple myeloma proteins and Bence Jones proteins; and group 2 molecules of normal gamma-globulin correspond antigenically to group 2 multiple myeloma proteins and Bence-Jones proteins. Among pooled human Fr II and several individual gamma-globulin preparations, approximately 60 per cent of molecules belong to group 1 and approximately 30 per cent of molecules to group 2 in this classification. The possible existence of a third minor antigenic group, constituting about 10 per cent, is discussed. Antisera to Bence Jones proteins of antigenic group 1 and group 2, in conjunction with I-131-labeled 7S gamma-globulin proved to be the most useful system for defining the antigenic groups of normal gamma-globulin. The group-specific antigenic determinants of normal 7S gamma-globulin molecules were located on the S fragments of these proteins.

FOUR CASES OF WALDENSTROEM'S MACROGLOBULINAEMIA

The clinical course and pathological features of four cases of Waldenström's macroglobulinaemia are described. One was associated with a localized carcinoma of the bronchus and one with a chromophobe adenoma of the pituitary. Trypsin digest preparations of the retina were examined in two cases, one with severe retinopathy and the other with no clinical evidence of ocular disease, and the findings are briefly described. The aetiology of the anaemia is discussed. Haemolysis due to circulating autoantibodies was not demonstrated in any of the cases. Erythrophagocytosis was a prominent feature in case 4, of moderate degree in cases 1 and 2, and inconspicuous in case 3. It was not proportionate to the serum macroglobulin levels. The cytological and histological features in all four cases are distinctive, and their value in differential diagnosis is stressed.

THE CELLULAR ORIGIN OF HUMAN IMMUNOGLOBULINS (GAMMA-2, GAMMA-1M, GAMMA-1A)

A study was made of the cellular origin of human immunoglobulins (γ₂, γ_1M, γ_1A). The results indicated that two closely related families of cells form immunoglobulins in human lymphoid tissue: germinal (reticular) centers and plasma cells. Thus their cellular origin in addition to their known antigenic relations further justifies placing the immunoglobulins in one family of proteins. Immunoglobulins were also formed to a small extent in primitive reticular cells which resembled those of germinal centers but were separated from them. Possibly such cells were undergoing transition to the much more numerous plasma cells with which they were commonly associated. The mantles of small lymphocytes which surrounded germinal centers did not contain detectable quantities of immunoglobulins. While in general only one type of immunoglobulin was present in an individual cell or germinal center, γ₂- and γ_1M-globulin were identified on occasion in the same plasma cell and germinal center. A peculiarity of the fetal thymus gland was the presence of immunoglobulin, mainly γ_1M, in a small number of cells of small and intermediate size and primitive reticular appearance and in Hassall's corpuscles.

Immunoglobulins and immunocytes

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Heavy chain subclasses of human gamma G-globulin. Serum distribution and cellular localization

Two antigenic types of naturally occurring proteins related to the papain produced F(c) fragment of gammaG-globulin have been studied. Most normal and myeloma gammaG-globulins are related to one or the other of these proteins, based on antigenic and structural characteristics of their heavy chain. Molecules bearing the determinant "Cr" are approximately 10 times as abundant as those bearing the determinant termed "Zu" in pools of normal gammaG-globulin and among a large group of gammaG-myeloma globulins. Both populations have properties of typical gammaG-globulin antibodies. Splenic cells, stained for these two populations with specific fluorescent antibody preparations, are found to contain one or the other of the two populations of gammaG-globulin, but not both. Approximately 10 times as many cells contain the Cr determinant as contain the Zu determinant.

GM and INV factors in subclasses of human IgG

Human G myeloma (7S gamma(2)-myeloma) proteins were investigated for relationships between Gm and Inv genetic factors and the different antigenic types of heavy polypeptide chains (gamma-chains) and light polypeptide chains. Myeloma proteins were isolated from the sera of 1 Chinese, 60 white and 28 Negro individuals. These 89 proteins were tested for eight Gm factors [Gm(a), Gm(x), Gm(b(2)), Gm(f), Gm(b(1)), Gm(b(3)), Gm(b(4)), and Gm(c)], and two Inv factors [Inv(l) and Inv(b)]. Results of the tests were correlated with the four gamma-chain subclasses (gamma(2a), gamma(2b), gamma(2c) and gamma(2d)) and the two types of light polypeptide chains, kappa-chains (type K or I) and lambda-chains (type L or II) found in human IgG molecules. 1. Gm factors were limited to myeloma proteins with heavy polypeptide chains of the gamma(2b)- and gamma(2c)-subclasses. No Gm factors were detected on gamma(2a)- and gamma(2d)-myeloma proteins or on a "heavy-chain" disease protein of subclass gamma(2d). 2. gamma(2b)-Proteins were positive for at least one Gm factor and were either Gm(a+), Gm(a + x+), or Gm(b(2)+ f+). 3. gamma(2c)-Myeloma proteins, and one gamma(2c)-"heavy-chain" disease protein, were positive for at least one Gm factor and contained various combinations of factors Gm(b(1)), (b(2)), (b(4)), and (c). Myeloma proteins from 3 Negroes were included in this group. 4. Inv factors (l) and (b) were limited to myeloma proteins with kappa-light polypeptide chains. These Inv factors were not detected on proteins with lambda-light polypeptide chains. 5. Most (70 per cent) of the gamma(2b)- and gamma(2c)-proteins with kappa-chains were Inv(l+) or Inv(b+). None of the gamma(2a)- or gamma(2d)-proteins with kappa-chains, however, contained these Inv factors.