Objective To analyze serum amyloid protein A (SAA) subtype and amino acid mutation sequence of the renal biopsy specimens from patients with renal amyloidosis secondary to ankylosing spondylitis (AS) by laser microdissection combined with mass spectometry.Methods Kidney biopsy formalin-preserved paraffin-embedded (FFPE) specimen slices were stained by Congo red,the positive areas of Congo red staining were selected by microdissection,after trypsin hydrolysis and filtration,peptide samples were subjected to liquid chromatography tandem mass spectrometry.Analysis softwares were used to evaluate the results,and the patient's amino acid sequence of SAA protein was compared to mutant amino acid sequence reported by literature or deduced from mutant SAA gene to determine whether there was a variation.Results SAA1 and SAA2 proteins with high abundance were identified by mass spectrometry,serum amyloid P and apolipoprotein E were also detected.No variation of SAA1 and SAA2 protein was detected.Conclusions The SAA1 and SAA2 proteins in AA amyloidosis secondary to ASwere identified for the first time,which enriched the pathogenesis of amyloidosis secondary to AS and provided a new method for the accurate classification of AA amyloidosis.

BACKGROUND:There are stil some controversies about lateral compression rotational y unstable pelvic ring injuries and fixed mode. OBJECTIVE:To evaluate the pelvic stability of locking plate fixation pelvic reconstruction repairing lateral compression rotational y unstable pelvic ring injuries. METHODS:We retrospectively analyzed 15 patients with unstable lateral compression rotational y unstable pelvic ring injuries treated with reconstruction locking plates fixation at Suzhou Xiangcheng People’s Hospital between November 2011 and November 2014. The Matta standard was used to evaluate the quality of fracture reduction. Clinical efficacy was evaluated by Majeed score. RESULTS AND CONCLUSION:Fifteen patients were fol owed up for 12-44 months (mean 24 months). According to the standard of Matta, 11 cases were excel ent, 2 cases were good, 2 cases were average, 0 case poor, and the excel ent and good rate was 87%. According to Majeed functional assessment, clinical function outcomes were graded as 9 cases excel ent, 3 cases good, 1 case average, 1 case poor;excel ent and good rate was 80%. There were no patient loss of reduction and internal fixation failure among these 15 patients in the final fol ow-up. No iatrogenic neurovascular injury occurred. Incision superficial infection was detected in 2 patients with a Morel-Laval ee lesion after subjecting to double-tube continuous negative pressure drainage, and healed after wound management. A large area of infection and skin necrosis did not occur. These results confirm that pelvic universal reconstruction locking plates in repair of lateral compression rotational y unstable pelvic ring injuries can maintain a strong and effective fixation. We should pay much attention to the cases of pelvic fractures combined with soft tissue injury around the pelvis.