Clinical and functional consequences of anti-properdin autoantibodies in patients with lupus nephritis.

Properdin is the only positive regulator of the complement system. In this study, we characterize the prevalence, functional consequences and disease associations of autoantibodies against properdin in a cohort of patients with autoimmune disease systemic lupus erythematosus (SLE) suffering from lupus nephritis (LN). We detected autoantibodies against properdin in plasma of 22·5% of the LN patients (16 of 71) by enzyme-linked immunosorbent assay (ELISA). The binding of these autoantibodies to properdin was dose-dependent and was validated by surface plasmon resonance. Higher levels of anti-properdin were related to high levels of anti-dsDNA and anti-nuclear antibodies and low concentrations of C3 and C4 in patients, and also with histological signs of LN activity and chronicity. The high negative predictive value (NPV) of anti-properdin and anti-dsDNA combination suggested that patients who are negative for both anti-properdin and anti-dsDNA will not have severe nephritis. Immunoglobulin G from anti-properdin-positive patients' plasma increased the C3b deposition on late apoptotic cells by flow cytometry. Nevertheless, these IgGs did not modify substantially the binding of properdin to C3b, the C3 convertase C3bBb and the pro-convertase C3bB, evaluated by surface plasmon resonance. In conclusion, anti-properdin autoantibodies exist in LN patients. They have weak but relevant functional consequences, which could have pathological significance.

Sarcopenia and high NLR are associated with the development of hyperprogressive disease after second-line pembrolizumab in patients with non-small-cell lung cancer.

The aim of this multi-center retrospective study was to evaluate the incidence of hyperprogressive disease (HPD) after second-line treatment with pembrolizumab in patients (n = 167) with metastatic non-small-cell lung cancer (NSCLC) whose tumors expressed programmed cell death ligand 1 (PD-L1) in ≥ 1% and to search for hematological and imaging biomarkers associated with its development. Prior to chemotherapy, neutrophil : lymphocyte ratio (NLR1) and platelet : lymphocyte ratio (PLR1), and prior to immunotherapy, NLR2 and PLR2 were retrospectively analyzed. The psoas major muscle area (PMMA) was calculated at the L3 position on computed tomography before chemotherapy (PMMA1) and before immunotherapy (PMMA2) (n = 112). Patients with ∆PMMA (1-PMMA2/PMMA1) × 100 ≥ 10% were considered to have sarcopenia (low muscle mass). After treatment with pembrolizumab on the first computerized tomography (CT) scan evaluation, patients were subdivided as follows as: hyperprogressors (HPs), progressors (Ps), non-progressors (NPs) and pseudoprogressors (PPs). HPs had significantly higher ∆PMMA levels, NLR2 and PLR2 than the other patients. Moreover, in multinomial logistic regression analysis, higher levels of ∆PMMA were associated with a decreased likelihood of being a P [odds ratio (OR) = 0·81; 95% confidence interval (CI) = 0·65-0·99; P = 0·047] or an NP (OR = 0·76; 95% CI = 0·62-0·94; P = 0·012) versus an HP. Higher NLRs tended to decrease the likelihood of being a P versus an HP (OR = 0·66; 95% CI = 0·42-1·06; P = 0·09) and significantly decreased the likelihood of being an NP versus an HP (OR = 0·44; 95% CI = 0·28-0·69; P < 0·0001). Our data suggest that a high pre-immunotherapy NLR2 and the presence of sarcopenia are potential risk factors for the development of HPD.

Association of rs172378 C1q gene cluster polymorphism with lupus nephritis in Bulgarian patients.

INTRODUCTION: Systemic lupus erythematosus (SLE) is a systemic autoimmune disease that can affect substantially any organ in the body. One of its most severe manifestations is lupus nephritis. Hereditary C1q deficiency is strongly related to SLE but there are very few and inconsistent studies exploring the single nucleotide polymorphisms (SNPs) of the C1q gene cluster in relation to the pathogenesis of SLE. In the present study we evaluated the possible association of gene variants in complement C1q gene cluster with susceptibility to lupus nephritis in a Bulgarian population, focusing on five previously associated with SLE SNPs in other populations. MATERIALS AND METHODS: Thirty-eight patients with lupus nephritis and 185 healthy controls, all from Bulgaria, were genotyped for the five C1q SNPs, rs587585, rs292001, rs172378, rs294179 and rs631090, by quantitive real-time PCR methods. We also determined C1q serum levels of C1q and haemolytic activity of C1q in relation to C1q genotypes. RESULTS: Lupus nephritis patients and healthy controls had statistically similar frequencies of genotypes and alleles of rs587585, rs292001, rs294179 and rs631090 SNPs. Nevertheless, minor G allele in rs172378 was significantly overrepresented in lupus nephritis patients when compared with healthy controls (36% vs. 23%, odds ratio = 1.80, 95% confidence interval = 1.06-3.06, p = 0.029). The SNP rs292001 showed a trend towards lower serum C1q levels in healthy controls. Two SNPs - rs294179 and rs292001 - were in a linkage disequilibrium in patients and healthy controls with different power (healthy controls: r (2 )= 0.6526, D' = 0.842; lupus nephritis patients: r (2 )= 0.491, D' = 0.686). The haplotype C-A-A-T-T in the patient group was associated with lupus nephritis: 7.7% vs. 0.8%, odds ratio = 10.81, 95% confidence interval = 1.45-80.57, p = 0.002. CONCLUSIONS: These results support the implication of the G allele in rs172378 as a risk factor for lupus nephritis in a homozygous status, at least for a Bulgarian population.

Prevalence and prognosis of PIK3CA mutations in Bulgarian patients with metastatic breast cancer receiving endocrine therapy in first-line setting.

BACKGROUND AND AIMS: In approximately 40% of patients with HER2-negative/HR-positive breast cancer tumors, the PIK3CA gene is mutated. Despite this, clinical outcomes vary between studies in this cohort. We aimed to ascertain the prevalence of PIK3CA mutations in patients with metastatic HR+/HER2- breast in Bulgaria, as well the evaluation and comparison of progression free survival (PFS) between wild-type (WT) and mutation-positive groups in the real-world setting. METHODS: Three oncology centers in Bulgaria collected 250 tissue samples between 2016 and 2022 for this multicentric retrospective study. PIK3CA mutations were identified using Real-Time qPCR. The median follow-up period was 35 months. RESULTS: The mean age of the mutant cohort was 57.6 ± 11.6 years, compared to 56.5 ± 12.2 years for the WT cohort (p = .52). The percentage of patients with visceral metastasis was 58.8% (n = 147). Approximately 84.3% (n = 210) of the patients had reached postmenopause. 29.2% (n = 73) of the patients had PIK3CA mutations. The predominant mutation was present in exon 20, H1047R (46.5%). We found a significant correlation only between the presence of a mutation and the metastatic diseases at diagnosis (p = .002). As first-line therapy, 67.1% of patients received endocrine therapy (ET) plus cyclin dependent kinase (CDK4/6) inhibitor, while the remainder received ET alone. The median PFS of patients in the group with the mutation was 32 months (95%, CI: 22-40) compared to 24 months in the WT cohort ((95%, CI: 21-36) (p = .45)); HR = 0.86 (95%, CI: 0.5-1.3) (p = .46). We corroborated our conclusion using propensity matching score analysis, (36 months [95% CI: 20-40] vs. 26 months [95% CI: 21-38], [p = .69]). CONCLUSIONS: We found that the prevalence of PIK3CA mutations in our patients was comparable to what has been reported in other nations. Our results suggest that PIK3CA mutational status has no bearing to ET efficacy in first-line setting.