C1 inhibitor deficiency: consensus document.

We present a consensus document on the diagnosis and management of C1 inhibitor deficiency, a syndrome characterized clinically by recurrent episodes of angio-oedema. In hereditary angio-oedema, a rare autosomal dominant condition, C1 inhibitor function is reduced due to impaired transcription or production of non-functional protein. The diagnosis is confirmed by the presence of a low serum C4 and absent or greatly reduced C1 inhibitor level or function. The condition can cause fatal laryngeal oedema and features indistinguishable from gastrointestinal tract obstruction. Attacks can be precipitated by trauma, infection and other stimulants. Treatment is graded according to response and the clinical site of swelling. Acute treatment for severe attack is by infusion of C1 inhibitor concentrate and for minor attack attenuated androgens and/or tranexamic acid. Prophylactic treatment is by attenuated androgens and/or tranexamic acid. There are a number of new products in trial, including genetically engineered C1 esterase inhibitor, kallikrein inhibitor and bradykinin B2 receptor antagonist. Individual sections provide special advice with respect to diagnosis, management (prophylaxis and emergency care), special situations (childhood, pregnancy, contraception, travel and dental care) and service specification.

A prospective controlled crossover trial of a new heat-treated intravenous immunoglobulin.

Twenty-one patients with primary immunoglobulin deficiency were enrolled in a crossover study to test the efficacy and safety of Alphaglobin in comparison with the licensed preparations Sandoglobulin and Gamimune. There was no statistical difference in these parameters between Alphaglobin and Sandoglobulin/Gamimune. The level of total serum IgG and specific IgG to pneumococcal polysaccharides was similar in individual patients when they were receiving Alphaglobin or one of the other products. Transient increases in serum alanine transferase occurred in five patients on Sandoglobulin/Gamimune and two patients on Alphaglobin. Some patients showed a rise in total serum IgM afterwards, indicating a response to infection. However, serum hepatitis C virus (HCV) RNA was not found during the alanine transferase (ALT) rises, and IgM antibody to hepatitis A virus (HAV) was negative afterwards. We conclude that Alphaglobin is a safe, well tolerated and clinically efficacious treatment for patients with primary antibody deficiency.

Carrier detection in families with properdin deficiency by microsatellite haplotyping.

Human properdin deficiency is an X-linked disorder strongly predisposing to meningococcal disease which has been recorded in over 50 cases of various ethnic origins. Immunochemically, total deficiency (type I), partial deficiency (type II), and deficiency due to a dysfunctional molecule (type III) can be differentiated. It is therefore most likely that the causative molecular defects will show considerable genetic heterogeneity. Analysis of the properdin locus at Xp11.3-Xp11.23 has led to the characterization of two polymorphic (dC-dA)n.(dG-dT)n repeats located approximately 15 kb downstream from the structural gene. Three families (two Scottish Caucasoid, one Tunisian Sephardic) with seven deficient individuals were investigated immunochemically and using a nonradioisotopic polymerase chain reaction-based method for microsatellite detection. Probable and definite carriers frequently showed properdin levels which were in the normal range. No recombinants between the microsatellite loci and properdin deficiency were detected, thus allowing identification of the defective allele through the generations in all three pedigrees. Haplotyping for these highly polymorphic microsatellites in close physical linkage to the properdin gene can provide rapid and nonradioactive detection of carrier status and prenatal diagnosis without extensive sequencing analysis.

A new fluorescent mitochondrial antibody: disease association.

The case notes of 34 patients whose sera contained an antibody giving an unusual immunofluorescent staining pattern were reviewed. This antibody designated M2(1) gave a slightly different pattern of staining on composite sections of rat liver, kidney and stomach from the primary biliary cirrhosis associated M2 antimitochondrial antibody. Anaemia was present in 10 patients, endocrine disease in 7 patients and autoimmune liver disease in 6 patients. We did not find the presence of M2(1) antibody to be of specific diagnostic significance. Although the M2(1) antibody is rare, caution is required in order to avoid confusion between this antibody and the M2 antimitochondrial antibody of primary biliary cirrhosis.

Measurement of circulating immune complexes containing IgG, IgM, IgA and IgE by flow cytometry: correlation with disease activity in patients with systemic lupus erythematosus.

The immunoglobulin (Ig) class of the antibody component of circulating immune complexes (IC) may be an important determinant of their pathogenicity. This study reports the development of a fluorometric immunoassay, using Raji cells as solid phase component and detection by flow cytometry, for the measurement of IC containing IgG, IgM, IgA and IgE. Analytic specificity of the method was established and diagnostic sensitivity determined in groups of patients with various disorders. In a detailed study of 44 patients with systemic lupus erythematosus (SLE), elevated levels of IC were observed in the majority of patients, the prevalence of the respective Ig subclasses within the patient group being IgG-IC (93%); IgM-IC (77%); IgA-IC (59%); IgE-IC (52%). Raised levels of IC (of all classes) correlated with disease activity. Longitudinal study of a patient with acute cerebral SLE revealed elevated IC levels of all four Ig classes at presentation which fell during treatment, coincident with normalization of complement values. The biological consequences of IC of various Ig subclasses is discussed with particular reference to a possible mechanism of IgE-IC mediated tissue damage.

T cell receptor beta chain polymorphisms are associated with cystic fibrosis.

The BglII polymorphism near the constant region of the T cell receptor beta chain (TCR c beta) has been investigated in normal controls, patients with cystic fibrosis (CF), and CF carriers. A significant increase was found in the frequency of the 10.0:9.2 kb heterozygous genotype in the CF carrier group (71%) as compared with normal controls (44%) (p = 0.005). Patients with CF also showed an increased frequency of the heterozygous genotype but this was not significant. These results represent a previously unreported disease association and suggest that there may be some form of epistatic interaction between the CF gene and the TCR beta genes such that the double heterozygote is immunologically advantaged.

Evaluation of five commercial kits to detect dsDNA antibodies.

Experiments were performed to evaluate five commercial kit assays used for the detection of antibodies to dsDNA. The kits were compared using a performance index score as recommended by the guidelines of the European Committee for Clinical Laboratory Standards. The highest performance score was obtained using the radioimmunoassay from Immunodiagnostic Services Ltd, with the Amersham kit second, the immunofluorescence test using Crithidia luciliae third, the Walker ELISA kit fourth, and the haemagglutination assay fifth. The results showed that none of the kits was outstanding, each appeared to detect a different anti-DNA antibody type as different results were obtained using each kit in assays of quality control sera, linearity of the method, antibody detection in various patient groups, and interference by various substances. It is suggested that laboratories using commercial assay kits for the detection of antibodies to dsDNA should decide which is the most appropriate to their particular needs and that a performance index scoring system may be useful in the comparison of assay evaluations between different laboratories.

Detection of circulating immune complexes by Raji cell assay: comparison of flow cytometric and radiometric methods.

Several flow cytometric methods for the measurement of circulating immune complexes (CIC) have recently become available. We report a Raji cell flow cytometric assay (FCMA) that uses aggregated human globulin (AHG) as primary calibrator. Technical advantages of the Raji cell flow cytometric assay are discussed, and its clinical usefulness is evaluated in a method comparison study with the widely used Raji cell immunoradiometric assay. FCMA is more precise and has greater analytic sensitivity for AHG. Diagnostic sensitivity by the flow cytometric method is superior in systemic lupus erythematosus (SLE), rheumatoid arthritis, and vasculitis patients: however, diagnostic specificity is similar for both assays, but the reference interval of FCMA is narrower. Significant correlations were found between CIC levels obtained with both methods in SLE, rheumatoid arthritis, and vasculitis patients and in longitudinal studies of two patients with cerebral SLE. The Raji cell FCMA is recommended for measurement of CIC levels to clinical laboratories with access to a flow cytometer.

Clinical and laboratory characteristics of patients with speckled pattern antinuclear antibodies.

Fifty patients whose sera contained a speckled antinuclear antibody (ANA) were interviewed and examined to determine if there was any relationship between their clinical manifestations and the presence of certain serological markers. The results suggest that speckled ANA is usually found in patients with definite connective tissue diseases, but a significant minority have incomplete or early stages of these diseases. Characterisation of the antibody to extractable nuclear antigen (ENA) and other serological markers does not normally assist in making a clinical diagnosis, but the detection of a speckled ANA should prompt further investigation and careful follow-up.

Lymphocytes from patients receiving lithium do not inhibit CFU-C growth.

Lymphocyte subset levels and function were examined in 12 patients on lithium therapy and in 11 healthy hospital personnel. Co-culture of allogeneic human bone marrow cells with monocyte-depleted lymphocyte preparations revealed that CFU-C formation was significantly reduced (mean 43% inhibition) in the presence of normal lymphocytes but not with the patients' lymphocytes (less than 5% inhibition). This did not reflect numerical changes in lymphocyte subsets, since these were similar for control and lithium subjects. T colony formation was significantly depressed in the patient group (P less than 0.05), whereas B colony numbers were similar in both groups (P greater than 0.1). The possible role of HLA-incompatibility affecting CFU-C growth was investigated in co-culture experiments, using lymphocytes from HLA-identical twins, one of whom was receiving lithium. In four separate co-culture experiments, the inhibitory effect was shown with lymphocytes from the non-lithium twin but was not demonstrated by the lithium subject. Addition of lithium in vitro to co-cultures of normal marrow and lymphocytes was found to negate the inhibitory phenomenon in a dose-related manner. It is postulated that granulocytosis induced by the administration of lithium may be a manifestation of changes in a lymphocytic control system.

Growth of human B cell colonies from peripheral blood of patients with systemic lupus erythematosus.

Human B cell colonies were grown from peripheral blood of 12 patients with systemic lupus erythematosus (SLE) and from 12 healthy control subjects. The SLE group showed a large increase (p less than 0.001) in the number of colony forming cells (CFC) present in peripheral blood as compared with controls. The CFC were of the pre-B cell type. There was also a loss of OKT8+ cell inhibition of B cell colony growth in the SLE group compared with control subjects.

Hypogammaglobulinaemia associated with long term, low dose steroid therapy.

Repeated pneumonia and hypogammaglobulinaemia was associated with long term low dose steroid therapy. Clinical improvement with restoration of antibody levels followed substitution of aerosol for oral therapy.

Detection and partial characterization of human B cell colony stimulating activity in synovial fluids of patients with rheumatoid arthritis.

The joint fluids of 37 patients with rheumatoid arthritis, eight patients with traumatic injuries to their joints, two patients with Reiter's syndrome and three patients with psoriatic arthritis were tested for the presence of B cell colony stimulating activity (B cell CSA). B cell CSA was found in all of the joint fluids from the patients with rheumatoid arthritis but in none of the joint fluids from patients with traumatic injuries to their joints or in the joint fluids from the patients with Reiter's syndrome. A trace of B cell CSA was found in the joint fluid of one of the three patients with psoriatic arthritis. There was a positive correlation (r = 0.796) between the amount of rheumatoid factor present in the joint fluids and the titre of B cell CSA. This correlation was highly significant (P less than 0.001). The B cell CSA was localized to component(s) with molecular weight ranges 115-129 kD and 64-72 kD and an isoelectric point of 6.8. Its activity was sensitive to reduction with 2-mercaptoethanol and to the oxidising action of potassium periodate.

Human B cell colony growth from pre-B cells in vitro.

We describe a simple one-step technique for the growth of human B cell colonies in semi-solid agar in vitro. This method used conditioned medium from the human plasmacytoma cell line LICR-LON-H My 2 as a source of stimulating activity. A linear relationship exists between the number of B cells seeded and the number of colonies formed (r = 0.95). Most colony forming cells, approximately 1 in 500 of B cells seeded, lack surface immunoglobulin, possess Fc receptors and mark with the Leu 12 monoclonal antibody. Cells within developing colonies are found to have cytoplasmic IgM, IgA and IgG depending on the length of time in culture.

Biochemical and physiochemical characteristics of a pre-B cell stimulating factor produced by the plasmacytoma cell line LICR LON HMY2.

We have characterized the pre-B cell colony stimulating activity (pre-B cell CSA) from LICR LON HMY2 conditioned medium (CM) by a variety of biochemical techniques. Pre-B cell CSA was found to be associated with a heat stable glycoprotein which has an isoelectric point of 8.3 and a mol. wt, as determined by polyacrylamide gel electrophoresis, of 28-32 kD. The relationship of this activity to previously described factors acting on cells of the B cell lineage is discussed.