Serum Levels of Joining Chain-Containing IgA1 Are Not Elevated in Patients with IgA Nephropathy

Figure 1

Selecting reliable and specific anti-J chain monoclonal antibodies to detect J chain. (a) Dot blot was performed to confirm the reactivity of anti-J chain monoclonal antibodies to pIgA purified from multiple myeloma patients. 7A6 has the best reactivity among 28 anti-J chain monoclonal antibodies. A1-A6: 2F9, 2B12, 3B2, 5G7, 3A9, 3B5; B1-B6: 6H6, 7A6, 10A5, 11C6, 19C8, and 20E11; C1-C6: 4A11, 5A9, 6D5, 9G6, 10F7, and 11C1; D1-D6: 10D11, 13A11, 15H10, 17H8, 19E10, and 21C7; (b) a sandwich ELISA for detecting the reactivity of anti-J chain to saliva which contains J chain-sIgA was performed. Anti-IgA antibody was immobilized on 96-well ELISA plates. After blocking, saliva samples were added and incubated for 2 h at room temperature. After washing, hybridoma cell culture supernatant was incubated. Plates were washed and incubated with HRP-conjugated goat anti-mouse antibody. The color was developed and the absorbance was measured at 405 nm. J chain: joining chain; pIgA: polymeric IgA; sIgA: secretory IgA; ELISA: enzyme-linked immunosorbent assay; HRP: horse radish peroxidase.

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