Validity of immunoglobulin-binding protein 1 as a biomarker for lupus nephritis.

BACKGROUND: Lupus nephritis (LN) is a major issue that adds a burden on patients with systemic lupus erythematosus (SLE). Immunoglobulin-binding protein 1 (IGBP1) is identified as a phosphoprotein that has been recently reported to be linked to the B-cell receptor complex and regulates differentiation, proliferation, apoptosis, and tolerance of B cells. Its diagnostic and/or prognostic role in LN has been highlighted only recently. OBJECTIVES: This study aims to evaluate the relation between serum IGBP1 and SLE disease activity and/or renal activity and to investigate the validity of IGBP1 as a biomarker for LN. METHODS: 96 participants were enrolled and divided into three groups: nephritis, nonnephritis, and control groups. The patients with SLE were diagnosed according to the Systemic Lupus International Collaborating Clinics classification (SLICC) criteria. The serum IGBP1 level was assayed using an enzyme-linked immunosorbent assay (ELISA). Assessments were conducted using the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2k) and renal biopsy for LN patients. RESULTS: The nephritis and nonnephritis groups had higher IGBP1 levels than the controls; the nephritis group had the highest serum IGBP1 levels (p < .001). Significant correlations were found between IGBP1 levels and proteinuria (r = 0.568, p = .001) and renal SLEDAI (r = 0.475, p = .006) in the nephritis group; on the other hand, the correlation of serum IGBP1 levels with SLEDAI-2K was non-significant for both groups (nephritis and nonnephritis groups). The IGBP1 levels were significantly different among histopathologic classes (p < .001), with class V showing the highest level. Moreover, it showed a significant positive correlation with the pathologic activity index. Compared with renal SLEDAI for identifying active renal affection in patients with SLE, the serum IGBP1 level with a cut-off value of 547.45 ng/mL is a valid biomarker for detecting active nephritis with 93.8% sensitivity and 96.9% specificity. CONCLUSION: The serum IGBP1 levels were high in patients with LN and were positively correlated with the pathologic activity index. The serum IGBP1 level of 547.45 ng/mL is a valid biomarker for detecting active nephritis. Thus, we recommend that clinicians monitor the serum IGBP1 level of patients with SLE to detect LN.

Association of Interleukin 13 rs20541 Gene Polymorphism and Serum Periostin with Asthma and Allergic Conjunctivitis Among Egyptian Patients.

Background: Single nucleotide polymorphisms (SNPs) in the interleukin 13 (IL13) gene are associated with vulnerability to allergic diseases, such as asthma and allergic conjunctivitis (AC). Periostin, as an IL13-induced protein, has emerged as a novel biomarker in several allergic diseases. Data among Egyptian patients are still scarce. Aim: To find out the association of IL13 rs20541 gene polymorphism and serum levels of periostin with asthma and AC among Egyptian patients. Patients and Methods: Eighty-one Egyptian allergic patients with asthma, AC, and both asthma and AC (27 each), were enrolled in this case-control study. Twenty-seven age and gender-matched healthy volunteers served as controls. All participants were tested for IL13 rs20541 SNP by real-time polymerase chain reaction, TaqMan method. Serum levels of periostin and IL13 were assessed by ELISA. Results: Compared to healthy subjects, asthmatic patients had a higher frequency of the homozygous adenine/adenine (AA) genotype at IL13 rs20541 SNP (14.8% vs 3.7%) and a lower frequency of the guanosine/guanosine (GG) genotype (51.9% vs 55.6%), while AC patients had higher GG genotype (70.4% vs 55.6%) with no AA genotype detected, yet no significant difference was noticed (p = 7.053). A significantly higher serum periostin in asthmatic patients compared to controls was found (p = 0.005). Higher levels of serum periostin, although nonsignificant, were recorded in AC patients compared to controls (22.88 ± 10.01ng/mL and 17.51 ± 3.17ng/mL, respectively). Periostin was significantly higher in patients with IL13 AA and GA genotypes compared to those with GG genotype (p = 0.016). A significant positive correlation between serum periostin and serum IL13 among allergic patients was recorded (r = 0.352, p < 0.001). Conclusion: Among Egyptian patients, serum level of periostin is significantly associated with asthma and positively correlates with IL13 level supporting its utility as a diagnostic biomarker. IL13 rs20541 gene polymorphism does not seem to play an obvious role in asthma and AC, which requires further evaluation.

Interleukin 10 -1082 G/A Gene Polymorphism and Susceptibility to Bronchial Asthma in Children: A Single-Center Study.

Interleukin-10 (IL-10) is the key regulator of immune responses preventing the undesirable exaggerated ones. Genetic variation in the promoter region of IL-10 may influence its serum level and contribute to susceptibility to bronchial asthma in children. This is a case-control study including 100 patients and 100 healthy control children who had undergone skin prick test, estimation of total IgE and serum level of IL-10 by enzyme-linked immunosorbent assay, and polymerase chain reaction-restriction fragment length polymorphism for IL-10 gene polymorphism. A significant association between IL-10 polymorphism and susceptibility to pediatric asthma was found. AA genotype represented (66%) of the patient group compared to (6%) only of the control group, while AG genotype was detected in 20% of patients and 4% of control. In contrast, wild genotype GG was found in 14% of patients and 90% of control with a highly statistically significant difference among both groups (P < 0.001). The serum level of IL-10 was significantly elevated in the GG genotype in comparison to other genotypes (P < 0.001), and it was negatively correlated with the severity of asthma among the studied pediatric asthmatic group (P < 0.001). In conclusion, IL-10 polymorphism may play an important role in the development of bronchial asthma in children.

Serum Level of CD48 and Its Expression on Blood Leukocytes in Persistent Asthmatic Patients.

CD48 is a surface receptor (mCD48) expressed on most hematopoietic cells, as well as in a soluble form (sCD48). It seems to play a major role in asthma through the interactions of mast cells with eosinophils via its ligand CD244. Hence, this study was done to evaluate the role of CD48, in its membrane and soluble forms, as a novel biomarker in asthma with various degrees of severity. One hundred participants were enrolled in this study and divided into 4 equal groups matched in age and sex; mild asthma, moderate asthma, severe asthma and apparently healthy controls. All were investigated for blood leukocytes mCD48 expression using flow cytometry and sCD48 in serum using ELISA. Our results revealed that the sCD48 was significantly elevated in patients with mild asthma compared with the controls (P<0.001) while significantly decreased in severe asthma than mild asthma (P<0.001) and moderate asthma (P=0.002) patient groups. Expression of mCD48 on eosinophils in moderate asthma group was significantly elevated compared with the control and the mild asthmatic groups (P<0.001). However, it was significantly decreased in severe asthma compared with moderate and mild asthma (P<0.001 and P=0.03, respectively). While it was significantly upregulated in severe asthmatic group compared to controls, patients with mild and moderate asthma on T-cell, B cells, Monocytes and NK cells (P<0.001 for all). In conclusion, CD48 may play a role in asthma and its level varies with severity of the disease being a useful marker in mild asthma.