Systemic lupus erythematosus with deficiency of the T4 epitope on T helper/inducer cells

Haematological manifestations of lupus

Our purpose was to compile information on the haematological manifestations of systemic lupus erythematosus (SLE), namely leucopenia, lymphopenia, thrombocytopenia, autoimmune haemolytic anaemia (AIHA), thrombotic thrombocytopenic purpura (TTP) and myelofibrosis. During our search of the English-language MEDLINE sources, we did not place a date-of-publication constraint. Hence, we have reviewed previous as well as most recent studies with the subject heading SLE in combination with each manifestation. Neutropenia can lead to morbidity and mortality from increased susceptibility to infection. Severe neutropenia can be successfully treated with granulocyte colony-stimulating factor. While related to disease activity, there is no specific therapy for lymphopenia. Severe lymphopenia may require the use of prophylactic therapy to prevent select opportunistic infections. Isolated idiopathic thrombocytopenic purpura maybe the first manifestation of SLE by months or even years. Some manifestations of lupus occur more frequently in association with low platelet count in these patients, for example, neuropsychiatric manifestation, haemolytic anaemia, the antiphospholipid syndrome and renal disease. Thrombocytopenia can be regarded as an important prognostic indicator of survival in patients with SLE. Medical, surgical and biological treatment modalities are reviewed for this manifestation. First-line therapy remains glucocorticoids. Through our review, we conclude glucocorticoids do produce a response in majority of patients initially, but sustained response to therapy is unlikely. Glucocorticoids are used as first-line therapy in patients with SLE with AIHA, but there is no conclusive evidence to guide second-line therapy. Rituximab is promising in refractory and non-responding AIHA. TTP is not recognised as a criteria for classification of SLE, but there is a considerable overlap between the presenting features of TTP and SLE, and a few patients with SLE have concurrent TTP. Myelofibrosis is an uncommon yet well-documented manifestation of SLE. We have compiled the cases that were reported in MEDLINE sources.

Henry Kunkel Festschrift

This Festschift by his former trainees is dedicated to the memory of Dr Henry G Kunkel. Dr Kunkel spent most of his academic life at The Rockefeller University. He has been called the father of Clinical Immunology. His trainees became professors and leaders in this field. Dr Kunkel's laboratory led to the elucidation of the immunology of the LE cell, the significance of anti-DNA and immune deposits in lupus nephritis, the recognition of antibodies to other nucleic acids and cellular constituents, the role of complement, genetics, hormones and cellular immunology--in the area of lupus and other rheumatic diseases.

Antibodies to CD4 in primary Sjögren's syndrome

OBJECTIVE

The purpose of this study was to examine whether antibodies against CD4 are present in patients with primary Sjögren's syndrome, and to explore the possible correlation between these antibodies and the CD4+ T lymphocyte depletion that is seen in some Sjögren patients.

METHODS

Sera from 214 patients with primary Sjögren's syndrome, 154 healthy blood donors, 38 age- and sex-matched controls without autoimmune disease, and 77 HIV-1-seropositive individuals were analysed by an enzyme-linked immunosorbent assay (ELISA) using recombinant soluble CD4 as the antigen.

RESULTS

Anti-CD4 antibodies were observed more frequently in patients with Sjögren's syndrome (12.6%) as compared with the control groups (0.6%) (P < 0.001), and at a level similar to that seen among the HIV-1 patients (13.0%). However, no correlation was found between the presence of anti-CD4 antibodies and CD4+ T lymphocytopenia in the Sjögren patients.

CONCLUSION

This is the first study that shows anti-CD4 antibodies in patients with primary Sjögren's syndrome. The significance of these antibodies in the immunopathogenesis of Sjögren's syndrome remains to be determined.

Clustering of non-major histocompatibility complex susceptibility candidate loci in human autoimmune diseases

Human autoimmune diseases are thought to develop through a complex combination of genetic and environmental factors. Genome-wide linkage searches of autoimmune and inflammatory/immune disorders have identified a large number of non-major histocompatibility complex loci that collectively contribute to disease susceptibility. A comparison was made of the linkage results from 23 published autoimmune or immune-mediated disease genome-wide scans. Human diseases included multiple sclerosis, Crohn's disease, familial psoriasis, asthma, and type-I diabetes (IDDM). Experimental animal disease studies included murine experimental autoimmune encephalomyelitis, rat inflammatory arthritis, rat and murine IDDM, histamine sensitization, immunity to exogenous antigens, and murine lupus (systemic lupus erythematosus; SLE). A majority (approximately 65%) of the human positive linkages map nonrandomly into 18 distinct clusters. Overlapping of susceptibility loci occurs between different human immune diseases and by comparing conserved regions with experimental autoimmune/immune disease models. This nonrandom clustering supports a hypothesis that, in some cases, clinically distinct autoimmune diseases may be controlled by a common set of susceptibility genes.

Evaluation of the child with suspected primary immunodeficiency

Infections are one of the major causes for visits to paediatricians. Most children recover without sequelae, untreated or if treated properly, and develop specific immunity towards the challenging microorganisms (mostly viruses). There is a small proportion of children however, with unusual frequent, severe, chronic, recurrent or opportunistic infections in whom an underlying immunodeficiency must be suspected. Based on current knowledge about the major types of congenital immunodeficiencies this review suggests a diagnostic approach to these children. Early evaluation will allow early identification of affected children and, subsequently, lead to proper treatment before devastating infections cause irreversible organ damage.

Primary Sjögren's syndrome and psoriasis vulgaris in a case of OKT4 epitope deficiency

We report a 29-year-old female OKT4 epitope deficiency patient with primary Sjögren's syndrome and psoriasis vulgaris. Immunological investigations during the prolonged clinical course of her herpes zoster revealed that she has OKT4 epitope deficiency and primary Sjögren's syndrome. She had been treated for psoriasis vulgaris for 17 years without systemic immunosuppressive therapy. Flow cytometric study revealed that her OKT4 deficiency is heterogeneous and excluded interference with the OKT4 epitope by anti OKT4 autoantibodies. The rare coexistence of primary Sjögren's syndrome and psoriasis implicates an immune disturbance due to an unusual phenotype of CD4.

A single amino acid substitution in a common African allele of the CD4 molecule ablates binding of the monoclonal antibody, OKT4

The CD4 molecule is a relatively non-polymorphic 55 kDa glycoprotein expressed on a subset of T lymphocytes. A common African allele of CD4 has been identified by non-reactivity with the monoclonal antibody, OKT4. The genetic basis for the OKT4- polymorphism of CD4 is unknown. In the present paper, the structure of the CD4 molecule from an homozygous CD4OKT4- individual was characterized at the molecular level. The size of the CD4OKT4- protein and mRNA were indistinguishable from those of the OKT4+ allele. The polymerase chain reaction (PCR) was used to map the structure of CD4OKT4- cDNAs by amplifying overlapping DNA segments and to obtain partial nucleotide sequence after asymmetric amplification. PCR was then used to clone CD4OKT4- cDNAs spanning the coding region of the entire, mature CD4 protein by amplification of two overlapping segments followed by PCR recombination. The nucleotide sequence of CD4OKT4- cDNA clones revealed a G----A transition at bp 867 encoding an arginine----tryptophan substitution at amino acid 240 relative to CD4OKT4+. Expression of a CD4OKT4- cDNA containing only this transition, confirmed that the arginine----tryptophan substitution at amino acid 240 ablates the binding of the mAb OKT4. A positively charged amino acid residue at this position is found in chimpanzee, rhesus macaque, mouse and rat CD4 suggesting that this mutation may confer unique functional properties to the CD4OKT4- protein.

Humans with OKT4-epitope deficiency have a single nucleotide base change in the CD4 gene, resulting in substitution of TRP240 for ARG240

The OKT4 epitope of the CD4 cell-surface protein has been shown to be polymorphic in white, black, and Japanese populations. The variable phenotypic expression is due to an alteration of the OKT4 epitope, since those persons lacking reactivity with OKT4 monoclonal antibody (mAb) are reactive with OKT4A-F mAb as well as other mAb specific for CD4. To determine the nature of this polymorphism at the gene level, we sequenced polymerase chain reaction-amplified genomic DNA containing the CD4-V3 and -V4 exons from American black subjects who are OKT4-normal, OKT4-negative heterozygous, or OKT4-negative homozygous. Comparison of the sequences revealed that the two CD4 exons are identical except for a cytosine-to-thymidine transition occurring at nucleotide position 868. This alters the first codon position of mino acid 240 and results in a tryptophan residue replacing an arginine residue. The change was also found in white and Japanese persons who are OKT4-negative.

Lack of Leu-3a epitope on T-helper (CD4) lymphocytes

Human T-helper cells express membrane-bound CD4 antigen whose many epitopes are recognized by different monoclonal antibodies. The epitope recognized by Leu-3a and similar clones has been shown to be the location for human immunodeficiency virus (HIV) receptor. We have found a unique blood donor whose CD4+ T-helper lymphocytes were lacking Leu-3a epitope. CD4+ T-helper cells lacking Leu-3a epitope might be resistant to HIV infection.

Expression of human CD4 by two human-mouse interlineage hybrids

Two hybrid cell lines expressing human CD4 were prepared by fusing human B-lymphoid cells with the mouse T-lymphoma BW5147. Hybrid TF42 was derived from a human B-lymphoblastoid line and TF53.1 from a human B-ALL. Variants of these hybrids expressing or lacking CD4 were isolated by sorting cells stained with the monoclonal antibody (mAb) OKT4 on a fluorescence-activated cell sorter (FACS). Cytogenetic, isoenzyme and DNA analysis confirmed the presence of human chromosome 12 in the CD4+ hybrids, and revealed that CD4 expression by TF42 was associated with multiple copies of this chromosome. Of seventy mAb recognizing human T-cell antigens screened on the CD4+ and CD4- variants of the two hybrids, only mAb recognizing CD4 and Leu 8 reacted with the CD4+ cells. These hybrids should be useful in the preparation, screening and analysis of anti-CD4 monoclonal antibodies, and in studies of CD4 epitopes recognized by HIV.

Molecular mechanisms of autoimmunity

Autoimmune diseases result from a combination of genetic susceptibility factors and exogenous influences such as infection or chemical (including drug) exposure. Germline DNA variations in genetic type as well as defects in antigen recognition acquired during thymic education of developing T-lymphocytes both contribute to impaired self: nonself discrimination and set the stage for later development of such diseases as myasthenia gravis, polymyositis, or systemic lupus erythematosus. In addition, drugs such as D-penicillamine, hydralazine, procainamide, or quinidine induce T-cell or B-cell changes which precipitate auto-reactivity and cause drug-induced disease. Intervention in autoimmune diseases with prednisone, alkylating agents or the future use of more selective monoclonal antibody reagents may be life-saving in some of these disorders.

Transient T-cell abnormality in a selective IgM-immunodeficient patient with Brucella infection

We describe here one 9-year-old female patient with an unusual form of selective IgM and CD4+ (OKT4+) helper/inducer T-cell immunodeficiency associated with Brucella infection. During the acute phase of Brucella infection, the percentage of infection. During the acute phase of Brucella infection, the percentage of peripheral blood lymphocytes (PBL) displaying OKT3+, OKT11+, and OKT4A+ phenotypes was decreased, and that of the OKT8+ cell was increased. These phenotypic T-cell abnormalities disappeared after antibiotic therapy in a 5-week period. However, the marked deficiency of CD4+ T cells and the IgM deficiency present during the acute phase of illness remained after recovery from illness. In vitro immunoglobulin production experiments during the acute phase of illness demonstrated that the patient's T cells lacked the capacity to provide helper/inducer function for normal B-cell differentiation to secrete IgM. The patient's T cells were also shown to possess IgM-specific suppressor cell activity on normal B- and T-cell differentiations. Thus impaired T-cell function was shown to be responsible for IgM-deficient antibody production. Defective interleukin 2 receptor expression and production by the patient's PBL in response to mitogenic stimulation also were present, indicating a severe defect in the patient's T-cell function.

Correlation between systemic lupus erythematosus and T4 epitope phenotype

Three groups of black subjects (systemic lupus erythematosus patients, patients with nonrheumatic disease, and normal subjects) were screened for the expression of the T4 epitope, as recognized by the monoclonal antibody OKT4. We found that the T cell subsets within each group were similar, regardless of the T4 epitope phenotype (intact, intermediate, or deficient). In the subgroup of Jamaican subjects, there was an association between systemic lupus erythematosus and the T4 epitope-intermediate and T4 epitope-deficient phenotypes; this association was not detected in the non-Jamaican population.

Human helper-T-cell function does not require T4 antigen expression

The relationship between immunoregulatory T-cell function and the expression of T-cell subset-specific differentiation antigens was examined using a phenotypically anomalous human T-cell line (TCL), termed H-1. H-1 cells were found to express T11, extremely high levels of T3, but no T4 nor T8 antigen. Despite their lack of T4 antigen expression, H-1 cells could be activated by coculture with pokeweed mitogen (PWM), anti-T3 antibody, or autologous B cells to provide potent help for B-cell differentiation into plaque-forming cells (PFC). In contrast, H-1 cells did not suppress the PFC response triggered by PWM-activated T4+ cells. These results demonstrate that the expression of the T-cell subclass-specific differentiation antigen, T4, is not required for a T cell to become activated and to implement the program for helper function. In addition, enhanced expression of T3 on the T4-, T8-, H-1 cell surface may reflect a compensatory upregulation of the T3/Ti receptor complex on T cells which are deficient in these nonpolymorphic associative recognition structures.

A method to average immunofluorescent histograms

Single parameter gated flow cytometric fluorescent histograms were obtained on normal donor blood mononuclear cells using several commonly available lymphocyte surface markers. A computer method was developed to average single parameter flow cytometric immunofluorescent histograms. The averaged histograms provide a means of pattern recognition for normal lymphocytes and will aid in the clinical evaluation of lymphocytosis. Averaged histograms may also serve as standards for more advanced analysis.

Clinical and serologic associations of the antiribosomal P protein antibody

Antibodies to the ribosomal P proteins (anti-P) were detected, by Western blot analysis, in the sera of 20 of 114 patients with various autoimmune disorders. Eighty-five percent of the patients with anti-P had systemic lupus erythematosus (SLE). Of 93 randomly selected patients, the frequency of anti-P was 7 of 59 SLE patients (12%) and 0 of 34 non-SLE patients. Approximately one-third of the patients with anti-P antibodies were male; approximately half were black. In contrast to the findings of some previous studies which used isolated ribosomes as antigen, an increased frequency of renal disease was not observed. Although the overall frequency of central nervous system lupus was similar in SLE patients with and those without anti-P, 6 of 6 patients with psychosis had anti-P antibodies. Western blotting was the most sensitive and specific method for the detection of anti-P antibodies; counter-immunoelectrophoresis and cytoplasmic indirect immunofluorescence were positive in only 47% and 65% of the anti-P-positive patients, respectively. Although 53% of the SLE patients with anti-P had concomitant anti-Ro antibodies, none had anti-La (as detected by counterimmunoelectrophoresis). Anti-P antibodies, therefore, appear to be relatively specific serologic markers for SLE and may be detected in the serum even when antibodies to double-stranded DNA are not found.