Three new mutations account for the prevalence of glucose 6 phosphate deshydrogenase (G6PD) deficiency in Tunisia.

A previous study on G6PD deficiency carried out on Tunisian population, led to the finding of seven different mutations with the prevalence of G6PD A- variant. This present study reports 23 new unrelated deficient subjects studied at the molecular level to determine the mutation that causes G6PD deficiency. Using PCR-SSCP of coding regions followed by direct sequencing of abnormal pattern, three new mutations were detected. Two of them are polymorphic intronic mutations. The first is IVS-V 655C-->C/T, found in four female subjects with mild deficiency of class III variant. The second is IVS-VIII 43 G-->A, found in three male subjects with mild deficiency of class III variant. The third mutation is in the exon region so that it changes the primary structure of the molecule. It is cited for the first time and named G6PD Tunisia. This variant affects the exon 7 of the gene at genomic position 15435 G→T. Its cDNA position is 93 G→G/T, it changes arg 246 to leu. This mutation was found in one heterozygote female with deficiency of class II who have had hemolytic anemia due to ingestion of fava beans. Finally, G6PD Med variant, reported before in three cases, was also found in five other cases (four heterozygote females and one male hemizygote). These findings first enlarge the spectre of mutations to be ten variant mutations, characterizing the Tunisian population and also contribute with hemoglobin gene research in our laboratory to trace the whole genetic map of Tunisian population.

B cell-ablative therapy: where are we now?

Based on their multifaceted functions, B cells participate in several pathological settings such as lymphoproliferative disorders, autoimmune diseases and graft rejection. B cell-ablative therapy has thus emerged as a mainstay in these diseases. A number of anti-B cell antibodies (Abs) have been generated, among which anti-CD20 Abs appear to be efficient. Rituximab (RTX) is one of these anti-CD20 monoclonal Abs. Originally approved for the treatment of non-Hodgkin lymphoma, RTX is now being administered in other malignant proliferations, applied to an increasing number of autoimmune diseases and required to prevent rejection of a graft. Although this medication is remarkably safe, a handful of laboratory tests have been proposed to monitor RTX-treated patients. The efficacy in different diseases, and the emergence of new anti-CD20 Abs raise many questions. Thus, their detailed understanding can lead to a better issue for inhibition of immune responses.

IgA glycosylation abnormalities in the serum of patients with primary Sjögren's syndrome.

Since there is no information regarding the glycosylation status of immunoglobulin A (IgA) in patients with primary Sjögren's syndrome (pSS), the sialic acid and galactose contents of IgA1 and IgA2 were evaluated in 17 pSS patients and in 14 normal controls (NC), using new enzyme-linked immunosorbent assays. The proportion of sialylated IgA1 and IgA2 was augmented (p < 0.001 and < 0.05, compared with NC), whereas that of galactosylated IgA1 and IgA2 was reduced (p < 0.01 and < 0.02, respectively). The level of SA IgA1 correlated the amount of IgA-containing immune complexes (p < 0.01), serum IgA (p < 0.01) and IgA-rheumatoid factor (p < 0.01). This demonstrates a number of IgA abnormalities in pSS patients. There were no correlations between SA and Gal, however, nor could any difference be ascribed to extraglandular manifestations.

Antiperinuclear factor of the IgA isotype in active rheumatoid arthritis.

OBJECTIVE: For rheumatoid arthritis (RA), antiperinuclear factor (APF) is as efficient a marker as rheumatoid factor (RF). However, the prevalence and significance of APF of the IgA isotype in active RA, as well as its correlation with RF-IgA, have not been determined. Our goal was to obtain information on these points. METHODS: APF-IgA were screened in 80 sera from patients with active RA, prospectively and consecutively selected over an 8-month period. Sera from 22 patients with Sjögren's syndrome and 50 with lupus were also studied retrospectively for APF-IgG and IgA. RESULTS: APF-IgA were found at a 1:10 dilution or above in 31 RA sera (39%), which were all positive for APF-IgG as well at higher titers. In the 64 sera positive for APF no correlations were found between APF-IgA and IgA or immune complexes-IgA, latex, the Rose-Waaler test and RF-IgA. Conversely, an association of APF-IgA was found with both APF-IgG (p < 0.0001) and anti-stratum corneum of rat esophagus (ASC)-IgG (p < 0.0001). APF-IgA, though correlated with the presence of secondary sicca syndrome in RA (p = 0.0023), was not more frequent (5/22) in primary Sjögren's sera. CONCLUSIONS: RF-IgA and APF-IgA are not correlated. Despite its localization in the mucosae, the target antigen for APF elicit fewer IgA antibodies in RA than does the RF target.

Tiopronine-induced reduction of rheumatoid factor functional affinity and asialylated IgG in patients with rheumatoid arthritis.

Serum and synovial fluid (SF) from 16 rheumatoid arthritis patients were evaluated before and after a 2-month treatment with tiopronine (TP). The levels of rheumatoid factor (RF) declined, as did the functional affinity of the remaining RF (p less than 0.01 in serum and p less than 0.05 in SF). Concomitant restoration of the sialylation of IgG was observed (p less than 0.05 in serum and SF). Following an initial increase, a significant reduction was observed in the level of soluble interleukin-2 receptors in serum (p less than 0.05) and SF (p less than 0.05) after treatment with TP.

Comparative study of four tests of bacterial infection in the neonate. Total neutrophil count, CRP, fibrinogen and C3d.

In a prospective study, the diagnostic value of C3d serum levels was compared with that of neutropenia, hyperfibrinogenemia and raised CRP in generalized neonatal bacterial infections. Serum C3d was evaluated using a counter-immunoelectrophoresis technique following a step of removal of C3 split products. Twelve patients with septicemia, 8 patients with highly probable infection and 134 normal controls were included in the study. The sensitivities for neutropenia, hyperfibrinogenemia, raised CRP and positive C3d were 21, 45, 60 and 70%, respectively, with a significant difference between the sensitivities of neutropenia and positive C3d (p < 0.01). The specificities were found to be 99.2, 99.2, 100 and 97.7% respectively. Thus the C3d qualitative test appears to be as reliable as CRP in the diagnosis of neonatal bacterial infections.

Decline of circulating immune complexes in rheumatoid arthritis: patients treated with tiopronine.

Fifteen patients with rheumatoid arthritis were treated with tiopronine, a new slow-acting drug, and various serological parameters were assessed before the onset and after two-month treatment. The latex test titres decreased, and there was a significant fall in the levels of IgA-containing circulating immune complexes in parallel with a depletion of plasma complement breakdown products.

The functional affinity of IgM rheumatoid factor is related to the disease duration in patients with rheumatoid arthritis.

OBJECTIVE: To determine the relevance of the functional affinity of IgM rheumatoid factor (RF) to the clinical and serological characteristics of patients with rheumatoid arthritis. METHODS: The functional affinity of IgM RF of 57 seropositive rheumatoid arthritis patients was evaluated by an enzyme linked immunosorbent assay based on the use of a chaotropic agent. The inhibition index was taken as an estimate of functional affinity. The patient group was divided into high functional affinity subgroup 1 (functional affinity < 0.5, n = 37) and low functional affinity subgroup 2 (functional affinity > 0.5, n = 20). The medical records of all patients were reviewed with a particular note of the disease activity and the articular damage score. RESULTS: The disease duration was shorter (P < 0.01) in subgroup 1 patients [7.9 (SD 6.4) years] than in subgroup 2 patients [13.4 (11.29) years], so that Ritchie's, Lee's, and Steinbrocker's indices were lower in the former than in the latter (P < 0.01, 0.001, and 0.01, respectively). In contrast, erythrocyte sedimentation rates, C reactive protein concentrations, antinuclear antibody, and HLA DR4 prevalences were similar in the two subgroups. CONCLUSIONS: Different forms of RF are present during progression of the disease.

Raised C-reactive protein response in rheumatoid arthritis patients with secondary Sjögren's syndrome.

The levels of serum C-reactive protein (CRP) were found to be significantly higher in the presence than in the absence of secondary Sjögren's syndrome in patients with rheumatoid arthritis, while the values of erythrocyte sedimentation rate and serum fibrinogen were not significantly different. The levels of CRP were found to be normal in 22 out of 24 patients with primary Sjögren's syndrome.

Some nutritional parameters in patients with rheumatoid arthritis.

Its was our aim to appreciate the respective influence of age, sex, duration of disease, inflammatory status and treatment on protein markers in patients with rheumatoid arthritis (RA). Serum albumin (SA), thyroxin-binding prealbumin (TBPA), transferrin and retinol-binding protein (RBP) were determined in 155 RA patients. Since the cut off, levels of these proteins are highly dependent on sex and age, several groups of sex- and age-matched normal controls were evaluated. The levels of SA (p < 0.03) and RBP (p < 0.002) were reduced in the women under 45 years of age. SA and RBP reached a nadir following one year of evolution. There were inverse correlations between SA and Lee's index (p < 0.01) and TBPA and Lee's (p < 0.05) and Ritchie's index (p < 0.01). Sa correlated inversely with the inflammatory status. The complex challenge of nutritional evaluation in RA patients is thus impossible to adequately portray and results should be interpreted with caution.

IgA-containing immune complexes in the circulation of patients with primary Sjögren's syndrome.

IgA-, IgM- and IgG-containing immune complexes (CIC) were detected in 48, 19 and 12% of 52 patients with primary Sjögren's syndrome (SS), in 36, 38 and 56% of 45 patients with rheumatoid arthritis, and in 8, 5 and 3% of 40 normal controls. A high proportion of primary SS patients also had considerable amounts of serum IgA and elevated levels of IgA with rheumatoid factor (RF) activity. IgA-CIC and IgA-RF were more frequent (P less than 0.03 and less than 0.001) in the 27 primary SS patients with, than in the 25 without extraglandular manifestations. IgA-CIC could play a role in mediating the tissue injury associated with primary SS.

The importance of C3d estimation in the diagnosis of generalized bacterial infections in newborn infants.

We evaluated the clinical relevance of a new C3d test in generalized bacterial neonatal infections. C3d was qualitatively evaluated by using an original counterimmunoelectrophoresis technique in 171 plasma. There were 13 cases of bacteriologically proven cases of septicemia and/or meningitis, 6 cases of probable and 42 cases of possible generalized infection. One hundred and ten non-infected samples were also tested. The sensitivity, specificity, positive and negative predictive values were 73.6, 83.6, 43.7 and 94.8%, respectively. The numbers of false positive and false negative were therefore found to be close to those observed when using classical infection markers.

Role of beta 2-glycoprotein I in the anticardiolipin antibody affinity for phospholipid in autoimmune disease.

The binding capacity to cardiolipin and the functional affinity of affinity-purified anticardiolipin (aCL) IgG of patients with autoimmune disease have been compared with those of individuals with malaria and acquired immunodeficiency syndrome (AIDS). The binding of autoimmune IgG aCL was enhanced gradually by the incorporation of increasing amounts of beta 2-glycoprotein I (beta 2GPI) into the assay, in contrast to that of patients with infectious diseases. In addition, there were significant reductions of functional affinity in autoimmune disease, but not in malaria or in AIDS. These results indicate that beta 2GPI requirement for binding to the target antigen varies inversely with functional affinity in autoimmune disease when beta 2GPI was present, and suggest that IgG aCL are more heterogeneous in this type of disorder than in patients with infectious disease.

[Decrease of the functional affinity of rheumatoid factors under the effect of tiopronin]. / Réduction de l'affinité fonctionnelle des facteurs rhumatoïdes sous l'effet de la tiopronine.

Sixteen rheumatoid arthritis patients were serologically examined, before and after a 2-month treatment with tiopronine (TP). The titer of agglutinating rheumatoid factor (RF) as well as the level of non-agglutinating RF were significantly reduced in serum and synovial fluid (SF). The functional affinity of the remaining RF was attenuated in serum (p less than 0.01) and SF (p less than 0.05). Conversely, the proportion of asialylated IgG was enhanced in serum (p less than 0.05) and SF (p less than 0.05). These findings would suggest that TP might restore the efficacity of sialyl transferase at the B lymphocyte level.