Iranian Journal of Immunology

Abstract Background: Endotoxin, widely present in the living environment of humans and animals, leads to endotoxemia during a short period. However, the long-term effects of endotoxin on immune function are unclear. Objective: To determine the importance of long-term endotoxin treatment on function of immune system. Methods: The mice were treated with different doses of lipopolysaccharide (LPS) for a month; the collected samples were then analyzed in terms of value changes in hematological parameters, lymphocyte subtypes, and immunoglobulins level. Results: The number of monocytes (MONO) and neutrophils (NEU) in the three treatment groups was significantly lower than the control after 30 days. However, the proportion of CD8+ T lymphocytes showed a rising trend in the mesenteric lymph nodes (MLNs) and Peyer's patches (PPs) while the CD4+ T cell was reduced. At the same time, a decrease was observed in the percentage of CD19+CD38+ B lymphocytes. Interestingly, the change of lymphocytes in PPs was more significant than that in MLNs, suggesting that immune response in the PPs occurred before the MLNs. Consistent with the changes in B cells, the content of IgA and IgG showed a downward trend. Conclusion: Long-term exposure to low-dose endotoxin had little or no effect on the immune function of the body, suggesting that the endotoxin can be rapidly eliminated by the immune system. Nonetheless, the number of immune cells was reduced in the high-dose group. T- and B-lymphocytes were significantly reduced, resulting in a decrease in immunoglobulin level, and showing a significant immune suppression state.

Abstract Background: Given the high mortality of bacterial bloodstream infections (BSI), blood culture results do not meet clinical needs timely due to being time-consuming and having low positive rate. Whether we can identify the severity and type of bacterial infections by cytokines is a controversial issue. Objective: To investigate the dynamic change of cytokines in BSI. Methods: 55 patients with Gram-positive (GP) BSI, 64 patients with Gram-negative (GN) BSI and 52 healthy controls were enrolled. We quantitatively detected the cytokines interleukin (IL)-2, IL-4, IL-6, IL-10, tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) by flow cytometry in the sera. The levels of procalcitonin, C-reactive protein, leukocytes and neutrophils were also detected simultaneously. Results: There were significantly up-regulated IL-6 and IL-10 expression in BSI patients, particularly in the GN-BSI, for instance Escherichia coli and Klebsiella pneumoniae infections; following the treatment, IL-6 and IL-10 decreased by 10-23 and 4-27 times, respectively. Additionally, IL-2, TNF-α and IFN-γ expression increased slightly in BSI patients and IFN-γ expression declined as GN-BSI progressed. Conclusion: IL-6 and IL-10 are closely associated with the severity and treatment efficacy of BSI, and can help to distinguish between GP-BSI and GN-BSI at an early stage.

Abstract Background: Programmed cell death protein 1 (PD-1) is a negative costimulatory molecule with immunomodulatory properties. Recently, PD-1 gene defects have attracted attention in the pathogenesis of SLE. Objective: Here, we assessed the association of PD-1 gene polymorphisms in intron 4 and haplotypes with the susceptibility to SLE. Method: Seventy-six SLE patients and 159 healthy controls were included. We screened the polymorphisms by amplifying the intron 4 of the PD-1 gene with the specific primers followed by sequencing. Results: Two distinct SNPs were identified (rs6705653 and rs41386439) within the intron 4 of the PD-1 gene. The AA genotype of +7499 (G/A) SNP was associated with the higher risk of SLE [OR=3.31, 95% CI (1.25-8.76), p-value=0.045], while A allele was identified as a risk allele [OR=1.75, 95% CI (1.10-2.76), p-value=0.015]. However, no significant association was observed between the allele and the genotype frequencies of +7209 (C/T) polymorphic region of the PD-1 gene and susceptibility to SLE. Haplotype analysis showed the significantly higher presence of H2 haplotype (AC; +7499/+7209) [OR=1.70, 95% CI (1.24-2.33), p-value=0.0012] in SLE patients. Conclusion: To the best of our knowledge, this is the first report of the significant association of PD-1 +7499 (G/A) SNP with the SLE susceptibility and the first detection of both polymorphic loci in a population from Iran. However, more investigations are necessary to confirm these findings.

Abstract Background: Functional single nucleotide polymorphisms in zinc transporter 8 (ZnT8) gene may be key determinants of humoral autoreactivity to ZnT8. Objective: The present study is expected to provide new information on the association of rs11558471 in ZnT8 gene with IL-17 levels and insulin resistance in an Iranian population [a high-risk population for type 2 diabetes (T2D)]. Methods: A total of 133 patients with T2D and 128 control subjects were included. Insulin and IL-17 concentrations were determined using ELISA. Insulin and fasting glucose levels were used to determine homeostasis model assessment for insulin resistance (HOMA-IR). The genetic analyses were performed by the restricted fragment length polymorphism (RFLP) after PCR amplification. Results: The risk allele frequency of rs11558471 in this Iranian population was among the highest in different populations. In T2D patients, compared with the GG genotypes, IL-17 concentrations were significantly higher in the GA+AA group (p= 0.042). According to the genotypes of this SNP, IL-17 concentrations, fasting glucose and HOMA-IR increased with the following order:GG

Abstract Background: Hereditary angioedema (HAE) is a rare genetic potentially life-threatening disease characterized by episodic non-pruritic subcutaneous and submucosal edema attacks in different parts of the body. Objective: To assess the status of Romanian HAE patients after the recent introduction of a new therapy through a nationwide program. Methods: This cross-sectional observational study included patients from the Romanian HAE Registry. Results: The study included 84 patients with HAE type I (91.7%) and type II (8.3%). The mean delay in diagnosis was 2.4 years in children and 16.7 years in adults (p=0.019). Stress and tiredness were the most frequent trigger factors. The majority of the HAE episodes involved subcutaneous (89.3%), abdominal (77.4%), genital (51.2%), facial (41.7%), and laryngeal (39.3%) symptoms during the preceding 12 months. One or several misdiagnoses were reported in 83.33% patients and 44.1 % of the patients were subjected to or proposed unnecessary surgery during abdominal episodes. Plasma-derived C1-INH (pdC1-INH) and recombinant C1-INH (rhC1-INH) were respectively used in 10 (11.9%) and 13 (15.5%) of the HAE patients for life-threatening attacks over the past 12 months. Fortythree (51.19%) patients practiced home treatment with subcutaneous injection of the bradykinin B2-receptor antagonist for acute HAE attacks. Conclusion: The significantly lower delay observed in children suggests an improvement in the awareness of C1-INH-HAE among physicians in recent years. The management of HAE in Romania has been somewhat enhanced as the majority of HAE patients have recently gained access to pdC1-INH, rhC1-INH, and bradykinin B2-receptor antagonist.

Abstract Background: Matrix metalloproteinases (MMPs) stimulate alveolar bone loss in chronic periodontitis. Objective: To evaluate the salivary and gingival crevicular fluid (GCF) levels of MMP-8 in patients with moderate to severe chronic periodontitis. Methods: 42 participants were divided into two groups: a case group (21 patients with generalized moderate to severe chronic periodontitis) and a control group (21 healthy periodontal subjects). GCF and saliva samples were obtained from both groups. Salivary and GCF MMP-8 levels of each subject were detected using the ELISA method. Results: Mean±SD values of salivary MMP-8 levels of the control and case groups were 1.52 ± 0.65 ng/ml and 6.06 ± 1.18 ng/ml, respectively, and statistically significant difference was observed (p=0.0001). Also, mean±SD values of GCF MMP-8 levels of the control and case groups were 0.87 ± 0.26 ng/ml and 2.92 ± 0.64 ng/ml, respectively; which was statistically significant (p=0.0001). Conclusion: Our results demonstrate an increased concentration of salivary and GCF levels of MMP-8 in the patient group.

Abstract Increased susceptibility to autoimmunity, malignancy, and allergy in addition to recurrent infections are the main characteristics suggesting for the primary immunodeficiency diseases (PID). CTLA-4 is predominantly expressed on activated and regulatory T-cells, which can bind to CD80/CD86 molecules on antigen-presenting cells as a negative regulator. Here, we describe a 24-year-old male born from consanguineous parents with heterozygous CTLA-4 mutation who presented with multiple autoimmune diseases. His past clinical history revealed alopecia areata at
four years old and subsequently, he developed Evans syndrome, type 1 diabetes mellitus, hypothyroidism, and chronic diarrhea while chronic rhinosinusitis and cytomegalovirus (CMV) colitis were the only infectious manifestations. Immunologic investigations revealed: low B cell count, abnormal Lymphocyte transformation test (LTT) to phytohemagglutinin (PHA), and hypogammaglobulinemia. Although all available treatments such as Intravenous Immunoglobulin (IVIG) therapy, immunosuppressive drugs, and antibiotic therapy were applied, diarrhea was not controlled due to colitis, which remained challenging. Whole exome sequencing was performed and the result showed heterozygous variant CHR2.204,735,635 G>A in the CTLA-4 gene, which was confirmed by the Sanger method. CTLA4 haploinsufficiency leads to autoimmune disorders, recurrent respiratory infections, hypogammaglobulinemia, lymphoproliferation with organ infiltration, and lymphocytic interstitial lung disease.

Abstract Afebrile Plasmodium vivax disease is believed to be extremely rare; and so is the association of a secondary immune thrombocytopenia due to Plasmodiun vivax malaria. This is a case of malaria presenting in an atypical manner. A middle aged male (31 years) came with occasional bleeding around gums, small petechial haemorrhages over chest and abdomen, and blood in stools for a few months, but no fever. In addition, the cervical lymph nodes were slightly enlarged. Spleen was 3 cm below costal margin. Platelets were found to have markedly decreased with clusters of megakaryocytes in the bone marrow. A possibility of Immune thrombocytopenic purpura was considered and immunoglobulin started intravenously, however platelet counts remained low. Later, in a follow up smear, trophozoites of P. vivax were discovered. Antimalarial drugs (Artesunate) were administrated for the patient along with IV immunoglobulins, to which he responded. It was revealed by flow cytometry that the ratio of helper to cytotoxic cells was reversed (0.9). This highlighted a rare case of afebrile malaria in association with immune dysregulation. Accordingly, malaria, though uncommon, could trigger immune thrombocytopenia.