ABSTRACT
Onconeural antibodies are found in many patients with paraneoplastic neurological syndromes (PNS) and define the disease as paraneoplastic. The study describes the presence of onconeural antibodies and PNS in 555 patients with neurological symptoms and confirmed cancer within five years, and compares the diagnostic accuracy of different antibody assays (immunoprecipitation, immunofluorescence and immunoblot). Onconeural antibodies were found in 11.9% of the patients by immunoprecipitation, in 7.0% by immunofluorescence and in 6.3% by immunoblot. PNS were present in 81.8% of the cancer patients that were seropositive by immunoprecipitation. Immunofluorescence and immunoblot failed to detect onconeural antibodies in almost one third of the PNS cases.
Subject(s)
Antibodies, Neoplasm/blood , Paraneoplastic Syndromes/diagnosis , Adult , Aged , Aged, 80 and over , Antibodies, Neoplasm/immunology , Female , Fluorescent Antibody Technique , Humans , Immunoblotting , Immunoprecipitation , Male , Middle Aged , Paraneoplastic Syndromes/blood , Paraneoplastic Syndromes/immunology , Sensitivity and Specificity , Young AdultABSTRACT
Poly-ADP-ribose polymerases (PARPs) use NAD(+) as substrate to generate polymers of ADP-ribose. We targeted the catalytic domain of human PARP1 as molecular NAD(+) detector into cellular organelles. Immunochemical detection of polymers demonstrated distinct subcellular NAD(+) pools in mitochondria, peroxisomes and, surprisingly, in the endoplasmic reticulum and the Golgi complex. Polymers did not accumulate within the mitochondrial intermembrane space or the cytosol. We demonstrate the suitability of this compartment-specific NAD(+) and poly-ADP-ribose turnover to establish intra-organellar protein localization. For overexpressed proteins, genetically endowed with PARP activity, detection of polymers indicates segregation from the cytosol and consequently intra-organellar residence. In mitochondria, polymer build-up reveals matrix localization of the PARP fusion protein. Compared to presently used fusion tags for subcellular protein localization, these are substantial improvements in resolution. We thus established a novel molecular tool applicable for studies of subcellular NAD metabolism and protein localization.
