(c) Some disease groups had relatively few patients, with sample sizes as small as three serum samples and even fewer CSF samples, limiting the ability to determine the frequency of antibodies within these groups accurately. IgM 2.5%, IgG 4.6%), they are also present in non-autoimmune diseases (serum IgM 1.2%, IgG 2.5%) and lack sensitivity and specificity towards being a diagnostic marker. Furthermore, anti-sulfatide antibodies are rarely found in CSF (e.g., no positive results for IgM), and including so-called borderline results ((+)) increases sensitivity and the false-positive rate in serum and CSF. == Discussion == While anti-sulfatide antibodies appear more frequently in neurological autoimmune diseases, they are rare overall and provide very limited diagnostic value in determining specific neurological diseases andmore importantlyif a neurological disease has a potential autoimmune etiology. Keywords:Anti-sulfatide antibodies, Sulfatide, Autoimmune, Neurological disorders == Introduction == Neurological autoimmune diseases of the peripheral [1,14] and the central nervous system [9] can be associated with anti-sulfatide antibodies, as they target sulfatides primarily found in myelin in the central [8,12] and peripheral nervous system [4,12]. While diseases like multiple sclerosis (MS) have other commonly used, clinically established laboratory parameters like oligoclonal bands (OCBs) available as diagnostic biomarkers, this circumstance is not the case for other diagnoses such as autoimmune polyneuropathies. Therefore, the diagnostic value of various antibodies as biomarkers, including ganglioside [7], paranodal/nodal [5], and anti-sulfatide antibodies [1,14], have been investigated in the past, although in parts, their diagnostic utility is currently increasingly questioned. For example, the added diagnostic value of anti-sulfatide antibodies has been viewed increasingly critically regarding inflammatory forms of polyneuropathy (e.g., [1,6,10]). Nevertheless, in the past decades, their additional diagnostic value in different medical fields has been increasingly questioned due to different studies showing their lack of diagnostic utility in specific neurological Rabbit polyclonal to ANGPTL7 disorders. Thus, a comprehensive study is required that provides reference regarding frequency, sensitivity, and specificity for anti-sulfatide antibodies for neurological disorders, both in the two compartments of our nervous systems, i.e., in serum and CSF, as antibodies against sulfatides have been proposed as a potential diagnostic marker for autoimmune processes affecting the myelin sheath of the entire nervous system. To fill this knowledge gap, we aimed to investigate anti-sulfatide antibodies in neurological disorders of the peripheral and central nervous system in serum and CSF and analyze the frequency of anti-sulfatide antibodies based on data from over 10 Cladribine years of application in our center. == Methods == == Study design, patients, and procedures == 1318 serum samples and 462 cerebrospinal fluid (CSF) samples from the neurological laboratory of the University Hospital Tbingen, Tbingen, Germany, collected between January 4, 2012, and November 23, 2022 were analyzed using anti-ganglioside dot kits (GA Generic Assays GmbH) for the evaluation of anti-sulfatide antibodies. Next, each line blots result was cross-referenced with the diagnosis documented in the related patients medical records. A medical student expert in neurology (NG) reviewed the medical records of all patients, extracting primary neurological diagnoses made during testing Cladribine when available. He then presented his findings to an experienced neurologist (JM), who eventually confirmed the diagnoses, based on all available clinical documentation (study workflow shown in Fig.1). Only patients with one test for either serum and/or CSF were included. The ganglioside antibodies included in the test have been previously published elsewhere [7]. The semiquantitative assessment of the color intensity of the blots was categorized according to the manufacturers recommendations into negative (), borderline (( +)), single positive (+), double positive (++), or triple positive (+++). Subsequently, the results categorized as single positive (+), double positive (++), or triple positive (+++) were grouped as positive, and those categorized as negative () and borderline ((+)) were grouped as negative. Due to the unclear significance of borderline findings ((+)), the impact of positively counting these findings was also separately evaluated. == Fig. 1. == Study workflow. Out of 3588 line blots, 28 were excluded. The remaining line blots, corresponding to 1318 serum samples and 462 CSF samples, were categorized into 14 disorders. These diseases were then grouped into two main categories and analyzed for frequency Each line blot was then correlated with the disease recorded in the patients medical records and sorted into one of 14 disease categories. Whenever feasible, the classification was assigned to a neurological autoimmune-related disease, such as GuillainBarr syndrome, acute motor axonal neuropathy (AMAN), MillerFisher Syndrome, multifocal motor neuropathy (MMN), chronic inflammatory demyelinating polyneuropathy (CIDP), other autoimmune polyneuropathies, MS, or other autoimmune encephalopathies. If the respective disorder did not suggest neurological autoimmune etiology, Cladribine the probe was sorted into a category of non-autoimmune diseases (other polyneuropathies, amyotrophic lateral sclerosis, other motor neuron diseases, other non-neurological conditions, and cases with no available diagnosis). == Statistical analyses == Data were analyzed using Statistical Package Cladribine for the Social Sciences (SPSS) version 29 for Windows, IBM.