ZSCAN1 Autoantibodies Are Associated with Pediatric Paraneoplastic ROHHAD

Abstract

ROHHAD), is a severe pediatric disorder of uncertain etiology resulting in hypothalamic dysfunction and frequent sudden death. Frequent co-occurrence of neuroblastic tumors have fueled suspicion of an autoimmune paraneoplastic neurological syndrome (PNS); however, specific anti-neural autoantibodies, a hallmark of PNS, have not been identified. Our objective is to determine if an autoimmune paraneoplastic etiology underlies ROHHAD. Methods: Immunoglobulin G (IgG) from pediatric ROHHAD patients (n = 9), non-inflammatory individuals (n = 100) and relevant pediatric controls (n = 25) was screened using a programmable phage display of the human peptidome (PhIP-Seq). Putative ROHHAD-specific autoantibodies were orthogonally validated using radioactive ligand binding and cell-based assays. Expression of autoantibody targets in ROHHAD tumor and healthy brain tissue was assessed with immunohistochemistry and mass spectrometry, respectively. Results: Autoantibodies to ZSCAN1 were detected in ROHHAD patients by PhIP-Seq and orthogonally validated in 7/9 ROHHAD patients and 0/125 controls using radioactive ligand binding and cell-based assays. Expression of ZSCAN1 in ROHHAD tumor and healthy human brain tissue was confirmed. Interpretation: Our results support the notion that tumor-associated ROHHAD syndrome is a pediatric PNS, potentially initiated by an immune response to peripheral neuroblastic tumor. ZSCAN1 autoantibodies may aid in earlier, accurate diagnosis of ROHHAD syndrome, thus providing a means toward early detection and treatment. This work warrants follow-up studies to test sensitivity and specificity of a novel diagnostic test. Last, given the absence of the ZSCAN1 gene in rodents, our study highlights the value of human-based approaches for detecting novel PNS subtypes.

Validation of a murine proteome-wide phage display library for the identification of autoantibody specificities

“…The PhIP-seq technique has been used extensively for the identification of autoreactivies in human sera and cerebrospinal fluid, including for the identification of novel autoimmune diseases (4)(5)(6)(7)(8)(9)(10)(11)13). While the technique has proven useful in human clinical investigations, a parallel murine PhIP-seq library provides new avenues to investigate immune dysregulation and disease in a tractable model organism.…”

“…In this regard, a typical approach has been to search for autoantibodies from affected mice in targeted assays such as western blotting and indirect immunofluorescence. Recently, there has been rapid development of new approaches to identifying autoantibody specificities that broadly cover the entire proteome in the human setting (4)(5)(6)(7)(8)(9). Thus, a similar approach in the mouse model could serve as an important method to further define and unravel autoimmunity.…”

Autoimmunity Related to Adipsic Hypernatremia and ROHHAD Syndrome

“…First, the presence or absence of symptoms at birth, the presence or absence of abnormal water metabolism, including Na levels, and the presence or absence of hyperprolactinemia are mentioned [29]. On the other hand, some autoimmunity and acquired factors, such as anti-SFO, anti-hypothalamus, and anti-ZSCAN1 autoantibodies, can be inferred in addition to the genetic predisposition [21,28,30].…”

“…One is the identification of a novel antigen called ZSCAN1 in ROHHAD cases with tumors, cases in which ROHHAD-like symptoms were observed after COVID-19 infection, and cases including adults with anti-Na x and anti-SFO antibody responses in adipsic hypernatremia and ROHHAD syndrome. Mandel-Brehm et al reported that ZSCAN1 autoantibodies were detected in patients with tumor-associated ROHHAD syndrome [21]. ZSCAN1 is a transcriptional factor and expressed in the hypothalamus [42].…”

“…Some of its causes have been investigated, mainly including genetic factors (e.g., imprinting abnormalities) and autoimmune factors that have been suggested since around 2019 [17][18][19][20]. Recently, autoantibodies to ZSCAN1 have been detected in patients with ROHHAD-NET [21]. Rituximab therapy has been administered to ROHHAD patients [20].…”