Presence Of Auto-Renal Tubular Antibodies In Sera Of Patients With Renal Tubular Acidosis

Objective:Renal tubular acidosis(RTA) is a form of metabolic acidosis due to dysfunction of proximal and (or)distal renal tubular,while the function of glomerulus is normal or slightly damaged.RTA is charactered as hyperchloraemic metabolic acidosis and electroly disorders.RTA patients often present as dipsesis.polydipsia,polyuria,renal rickets/osteomalacia,nephrocal cinosis and so on. Renal tubular acidosis is often classified by four types:type I (distal renal tubular acidosis, dRTA) ,type II (proximal renal tubular acidosis,pRTA) ,typeIII (mixed renal tubular acidosis ) as well as type IV (hyperkaliemia renal tubular acidosis) . Renal tubular acidosis(RTA) was once defined as a type of heritage disease.But more researches indicate that RTA is associated with various immunological diseases which demonstrates that there are possibly internal association between RTA invasion and autoimmune factors. Of the total,type I RTA is the most common.Type I RTA is often a kind of sporadic disease in adult and familial disease in children.Sporadic diseases may be primary(almost in women) or secondary.For example.it can be secondary to some autoimmune diseases combined with hypergammaglobulinemia,especially sjogren syndrome(SS).The kidney damage is common in sjogren syndrome. The incidence rate is different according to different reports and most consider 40%-50%. The kidney damage mainly involves in distal renal tubular and occurres renal tubular acidosis. Immunofluorescence assay is based on antigen-antibody reaction and has high degree of specificity,by which tumer markers with fluorchromes such as FITC,RB200 and so on react with antigens or antibodies known,and then determine the unknown antigens or antibodies. What makes up of fluorchromes and antibodies are called fluorescent antibodies (FA).Fluorescent antibodies conjugated with corresponding antigens can manifest different degree fluorescent light.Therefore, we can detect antigens qualitatively, quantitatively or site-specificly.The experiment is to detect anti-renal tubular antibodies in sera of renal tubular acidosis qualitatively with anti-human IgG marked by FITC. Methods:1. Objects:sera of 11 patients diagnosed renal tubular acidosis.Diagnosis standard: ①metabolic acidosis and PH value of urine>6.0;②hyponatremia, hypopotassaemia, hypocalcemia and hyperchloraemia; ③ostalgia and osteomalacia; ④osteoporosis, pathologic fracture or lithangiuria and so on.Ten shares of fasting sera of healthy people that did not have a cold or anything medicine three months ago,and match with the renal tubular acidosis patients in gender and age. Diagnosis standard of SS: ① aridity keratitis.②oral xerosis.③anyone of these antibodies is positive:anti-SSA,anti-SSB,ANA>1:20,RF>1:20.Anybody that accords with three standards above and remove other connective tissue diseases, sarcoidosis, lymphadenoma and so on can be diagnosed SS. Phosphate-buffered saline takes place of sera in blank control.2 Methods: ①anti-TBM:Monkey-kidney indirect immunofluorescence kit was bought from Euroimmun Company.At the first incubation, diluted sera_reacted with monkey-kidney frozen sections fixed in slide reaction zones.If the sera are positive,specific IgG,IgA,IgM antibodies will combine with corresponding antigens.Combined antibodies reacted with anti-human antibodies marked by FITC,and then we observed specific fluorescence models under fluorescence microscope. ②anti-renal tubular cytoplasm antibody :human kidney par. sections,traditionary wet box, 10% goat sera to block nonspecific combining sites,stock solution used in the first time,observation and collection pictures by microscope. ③Sera of RTA patients were detected biochemistry,serin electrophoresis, blood sedimentation,ANA,ENA,urine routine,24-hour-urine protein quantitation. Some was proceeding thyroid function, kidney B ultrasound and bone density examination.3. Statistical analysis:All data would be represented by mean ±standard deviation (x|-±s) .Means of each group were compared by t-test or t'-test.Analysis level isα=0.05. Results: The positive rate of RTA patients sera is 6/11,highly larger than that in SS groups (1/10) and healthy controls. Conclusions:The RTA patients have anti-renal tubular antibodies and mainly anti-renal tubular cytoplasm.So we konw the morbidity of RTA is associated with autoimmune factors. Significance:There are many research reports about immune pathogenesis of RTA but still no sufficient experiment evidences.The treatment of RTA continues to use traditional methods:retrieve acidosis and electrolyte disturbances and so on. In our experiment,we found that RTA patients had auto-antibodies.It is important for us to be provided help in RTA pathogenesis and treatment research.