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A Hollmann

Publications and source records attributed to A Hollmann.

At least 19 recordsLinked to original sources
PubMed1992

Unusual sequence of immunoglobulin L-chain rearrangements in a gamma heavy chain disease patient.

Patients with gamma heavy chain disease (gamma-HCD) generally produce incomplete immunoglobulin (Ig) gamma-heavy chains (gamma-HCD protein) which cannot associate with light chains (IgL). In most patients Bence Jones proteins (BJP) are not observed. However, in the 61-year-old patient WIN we found gamma l-HCD proteins and lambda BJP in serum and urine. WIN gamma l-HCD protein does not carry the Ig Fd region, has a molecular weight of 33.5 kDa, and the seven N-terminal amino acid residues are not translated from any of the known immunoglobulin heavy chain (IgH) gene sequences. These residues are followed by the C gamma l-hinge region. In DNA from peripheral blood lymphocytes of patient WIN we found bands representing dominant rearrangements in one of the two alleles of the IgH, Ig kappa and Ig lambda locus. Taken together, the data from protein and DNA analysis strongly suggest, albeit do not formally prove, that one dominant B-cell clone which carries a rearranged and a non-rearranged allele of each Ig locus produces gamma-HCD protein and lambda BJP. The productive lambda-gene rearrangement in this clone thus has not been preceded by abortive rearrangements in both kappa-locus alleles. Lymphocytes with an unusual sequence of IgL-chain gene activation seem to be involved in the case of gamma-HCD described here.

Amino Acid Sequence↗
PubMed1991

[Gamma-1 heavy chain disease with the demonstration of Bence-Jones proteins].

We describe a 61-year-old patient suffering from gamma-1-heavy-chain disease (gamma 1-HCD) associated with Bence-Jones-lambda proteinemia and proteinuria. The analysis of the patients gamma 1-HCD protein (WIN) shows a deletion of the complete Fd fragment. The N-terminal seven amino-acid residue does not resemble any of the known immunoglobulin-heavy-chain variable regions. Unexpectedly, in PBL-DNA and in DNA from EBV-immortalized cells we found in addition to the expected predominantly rearranged Ig-lambda-light-chain gene a predominant rearrangement of an Ig-kappa gene. These findings show that the gamma-1-heavy-chain disease of the patient involves a defective regulation of Ig-light-chain-gene activation as well.

Amino Acid Sequence↗
PubMed1990

[Immunoglobulin and T-cell receptor gene rearrangements in patients with autoimmune diseases].

Immunoglobulin-(Ig-) and T-cell-receptor-(TcR-)gene rearrangements were investigated in peripheral blood lymphocytes (PBL) of patients with various autoimmune disorders. In patients with SLE there was no predominant Ig- or TcR-gene rearrangement. This was also true in patients with a long disease duration and with excessive hypergammaglobulinemia. These results lead us to suggest that B cells are activated polyclonally in these patients. In those cases, where predominantly rearranged Ig- or TcR-genes were found, the autoimmune disorder was associated with a low-grade non-Hodgkin lymphoma (NHL). This coherence of B-cell malignancy and autoimmunity was only found in patients with cryoglobulinemia (KG), cold agglutinin disease (KA), and hemolytic anemia (AIHA).

Adult↗
PubMed1989

Predominant immunoglobulin gene rearrangements in two patients with immunodeficiency: restricted use of V gene segments and DNA hypermethylation.

The majority of common variable immunodeficiencies (CVID) is caused by intrinsic B cell defects which impede distinct stages of B cell differentiation. B cell differentiation is accompanied by the rearrangement of immunoglobulin (Ig) genes. The first step in the rearrangement process is the assembly of IgH genes, and subsequently, IgL genes are rearranged. During B cell maturation, Ig genes are demethylated in a stepwise, locus-specific manner. Here, we examined the Ig gene rearrangements of four patients with classical CVID and of one child suffering from an unusual immunodeficiency associated with CD5+ B cell lymphocytosis. In one of the four adult patients with CVID, we observed a predominant type of VHDJH-gene rearrangement. In the child, different polyclonal VHDJH-gene rearrangements were found together with a predominant type of kappa light chain gene rearrangement. The rearranged kappa chain genes were methylated (as in the pre-B cell stage). These findings together with the cell phenotype analysis and the clinical course of the disease in the child suggests that in some patients with primary immunodeficiency a maturation arrest may occur in B cells leading to a predominant Ig V gene rearrangement.

Adolescent↗
PubMed1989

[Unusual immunoglobulin gene rearrangements in patients with immunodeficiency].

In a 64-year-old patient with typical common variable immunodeficiency (CVID) DNA prepared from peripheral blood lymphocytes (PBL) showed a prominent immunoglobulin heavy chain (IgH) gene rearrangement; the immunoglobulin light chain (IgL) genes were found to be in the germline configuration. In contrast, a 13-year-old girl with a hitherto unidentified immunodeficiency showed polyclonal IgH gene rearrangements and a dominant IgL gene rearrangement. In both cases neither monoclonal B-lymphocytes nor monoclonal immunoglobulins were detectable. Our explanation for this unusual observation is that V-gene use in a given B-cell is not entirely random. This may be the consequence of a maturation arrest of B-cells.

Adolescent↗
PubMed1988

IgD/lambda plasmocytoma with immunoglobulin kappa light-chain genes in the germ-line configuration.

Human immunoglobulin (Ig) genes are rearranged in an ordered sequence of events during B-cell differentiation: starting at the IgH locus, a productive VHDJH rearrangement leads to the expression of mu chains. Light-chain gene rearrangements have been found in pre-B cells which express mu chains. In these cells rearrangements of Ig kappa light-chain genes precede that of lambda genes. In an IgD/lambda-producing plasmocytoma, however, we found an apparent exception to this rule: the kappa genes were not rearranged. Together with the observation that roughly 90% of human IgD plasmocytomas produce lambda light-chain proteins, the finding reported here leads us to suggest that lambda light-chain genes are rearranged preferentially in IgD-producing plasma cells. Ig gene rearrangement, isotype switch, and the phenomenon of isotypic and allelic exclusion are discussed with special reference to our findings.

Gene Rearrangement↗
PubMed1988

[Unusual rearrangements of immunoglobulin genes in a patient with IgD/lambda plasmacytoma].

The mechanisms of Ig gene expression in B-lymphocytes are not yet fully understood. A hierarchy of Ig gene rearrangements has been suggested starting with Ig heavy chain genes followed by kappa and lambda light chain genes. According to this principle, B-cells with productive lambda light chain expression have their kappa genes either unproductively rearranged or deleted. By examining B-cells from patients with various lymphoproliferative diseases the developmental hierarchy of the Ig gene rearrangements could be confirmed with one notable exception: in a patient with IgD/lambda-plasmocytoma we found the kappa genes in germ line configuration. This finding points to an aberrant light chain gene expression in IgD-producing plasma cells.

Alleles↗