Association between Serum Biomarkers and Peripheral Neuropathy in Microscopic Polyangiitis

Unleashing the Power of Multiomics: Unraveling the Molecular Landscape of Peripheral Neuropathy

Peripheral neuropathies (PNs) affect over 20 million individuals in the United States, manifesting as a wide range of sensory, motor, and autonomic nerve symptoms. While various conditions such as diabetes, metabolic disorders, trauma, autoimmune disease, and chemotherapy-induced neurotoxicity have been linked to PN, approximately one-third of PN cases remain idiopathic, underscoring a critical gap in our understanding of these disorders. Over the years, considerable efforts have focused on unraveling the complex molecular pathways underlying PN to advance diagnosis and treatment. Traditional methods such as linkage analysis, fluorescence in situ hybridization, polymerase chain reaction, and Sanger sequencing identified initial genetic variants associated with PN. However, the establishment and application of next-generation sequencing (NGS) and, more recently, long-read/single-cell sequencing have revolutionized the field, accelerating the discovery of novel disease-causing variants and challenging previous assumptions about pathogenicity. This review traces the evolution of genomic technologies in PN research, emphasizing the pivotal role of NGS in uncovering genetic complexities. We provide a comprehensive analysis of established genomic approaches such as genome-wide association studies, targeted gene panel sequencing, and whole-exome/genome sequencing, alongside emerging multiomic technologies including RNA sequencing and proteomics. Integrating these approaches promises holistic insights into PN pathophysiology, potentially revealing new biomarkers and therapeutic targets. Furthermore, we discuss the clinical implications of genomic and multiomic integration, highlighting their potential to enhance diagnostic accuracy, prognostic assessment, and personalized treatment strategies for PN. Challenges and questions in standardizing these technologies for clinical use are raised, underscoring the need for robust guidelines to maximize their clinical utility.

Comparative analysis of renal decline rates in microscopic polyangiitis: unveiling the slowly progressive phenotype

Although rapidly progressive glomerulonephritis (RPGN) is the main renal phenotype of microscopic polyangiitis (MPA), we aim to clarify the clinical features of slowly progressive MPA. This retrospective observational study included 12 patients diagnosed with MPA in our hospital between January 2012 and February 2022. We investigated the differences in surrogate markers, rate of decline of estimated glomerular filtration rate (eGFR) between the slowly progressive and rapidly progressive MPA groups. Of the 12 patients with MPA, 3 (25.0%) had slowly progressive MPA: MPA within 30% decrease in eGFR 3 months pretreatment, all of whom developed RPGN during the course. Patients with slowly progressive MPA had lower levels of C-reactive protein, myeloperoxidase anti-neutrophil cytoplasmic antibodies, and interleukin-6; higher levels of sialylated carbohydrate antigen KL-6. Slowly progressive MPA is not uncommon in our hospital. A linear relationship was found between slower rate of eGFR decline and lower surrogate markers of disease activity. Some MPA cases have slowly progressive glomerulonephritis leading to RPGN, which may be clinically characterized by low disease activity. It may be useful to measure myeloperoxidase anti-neutrophil cytoplasmic antibody in chronic kidney disease with concomitant urinary abnormalities to diagnose MPA with slowly progressive glomerulonephritis.

Predictive Value of GDF-15 and sST2 for Pulmonary Hypertension in Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Objective

To confirm whether growth differentiation factor-15 (GDF-15) and soluble suppression of tumorigenicity 2 (sST2) are indicators of pulmonary hypertension in acute exacerbation of chronic obstructive pulmonary disease (AECOPD-PH).

Methods

All patients admitted to the hospital with AECOPD between July 2020 and October 2021 were enrolled. The patients were then categorized into AECOPD and AECOPD-PH groups according to PH probability, and the differences in GDF-15 and sST2 serum levels in the AECOPD and AECOPD-PH groups were compared. Correlation analysis was carried out to explore the association between GDF-15 and sST2 serum levels and the length of hospital stay of patients with AECOPD-PH. Receiver operating characteristic curve analysis was used to assess the clinical significance of GDF-15 and sST2 in predicting patients with AECOPD-PH.

Results

Included in this study were 126 patients with AECOPD, including 69 with AECOPD and 57 with AECOPD-PH. The serum levels of GDF-15 and sST2 in the AECOPD-PH group were significantly higher than those in the AECOPD group (P < 0.05). There was no significant correlation between the length of hospital stay in AECOPD-PH patients and GDF-15 and sST2 serum levels (P > 0.05). The area under the curves of GDF-15, sST2, and GDF-15 + sST2 for predicting AECOPD-PH and AECOPD-PH patients with poor prognosis were >0.60 and 0.70, respectively. The optimal cutoff values of GDF-15 and sST2 for predicting AECOPD-PH were 1125.33 pg/mL and 80.68 ng/mL and 1309.72 pg/mL and 59.10 ng/mL for predicting AECOPD-PH patients with poor prognosis, respectively.

Conclusion

GDF-15 and sST2 levels may be useful in the prediction of AECOPD-PH.