The Contrast Analysis Between The Coombs-negative Autoimmune Hemolytic Anemia And Coombs-positive Autoimmune Hemolytic Anemia

Autoimmune hemolytic anemia (AIHA) is characterized by the production of antibodies directed against self red blood cells (RBC) through activating complement proteins or reticuloendothelial system, and they shorten the life of RBC by immune disorders. AIHA is a fairly uncommon disorder, with estimates of the incidence at 1-3 cases per 100,000 per year, the onset is always the middle aged people, and females are more than males. It can be divided into primary AIHA and secondary AIHA by etiopathogenisis. Approximately primary AIHA takes up 50%, other 50% can find its etiology, which secondary to other autoimmune disorders, such as lymphoproliferative disorders, autoimmune disease, infection (virus and tuberculosis) and drug-induced hypersensitisation. Recent years, the percentage of secondary AIHA increases, Hdocman reported in 2002 that secondary AIHA take up 72%.AIHA are generally classified according to the characteristic temperature reactivity of the RBC autoantibody, that is warm AIHA (WAIHA) and cold AIHA. Coombs test is main marker of (WAIHA). However we found cases fit for clinical characters of WAIHA with negative result of Coombs test, which may release by glucocortcoid, and we call it Coombs-negative Autoimmune Hemolytic Anemia. The incidence was 2-4% overseas, however, according to national scholar the number is 23%. Studys of Coombs-negative AIHA has not been reported by foreign scholars, and national scholars have different opinion on this topic. And this kind of disease belongs to excluded disease, so make its characters clear is of great value in clinical diagnosis and treatment.Objective: By comparing cases between Coombs-negative AIHA and Coombs-positive AIHA, we can find out chracters of Coombs-negative AIHA, which can make us understand it clearly, and can discuss the reason why Coombs is negative in order to raise coincidence rate.Methods: 100 cases from January 1st 2000 to December 31st 2007 in our hospital with intact document and regular treatment was selected. (Certain examination was done to exclude hereditary spherocytosis, paroxysmal nocturnal hemoglobinuria and other hemolytic diseases). They were divided into Coombs-negative group (negative group):22 cases and Coombs-positive group by Coombs test (positive group): 78 cases. Clinical characters, laboratory examination, prognosis and response to treatment were compared between this two groups.Result: (1) Coombs-negative group takes up 22%, median age is 38 (17-73); male: female is 1:3.4; Coombs-positive group takes up 78%, median age is 45 (13-85), male: female is 1:1.7. (2) Clinical features and laboratory examination: RBC: negative group (1.98±0.77)×10¹²/L, positive group (1.64±0.74)×10¹²/L, (P<0.05); Hb: negative group (72.50±20.15) g/L; positive group: (60.00±21.37) g/L, (P<0.05).C linical obvious jaundice rate: negative group 54.55%, positive group 87.18% (Χ² = 24.74, P < 0.05); IBIL: negative group (35.53±27.05) umol/L, positive group (55.85±39.33) umol/L. (P< 0.05). negative group Splenomegaly rate is 40%, rate of accompanied with heptomegly is 9.91%; positive group: Splenomegaly rate is 55.12%, heptomegly rate is 16.67%, (P>0.05). Compensational proliferative degree of bone marrow:reticulocyte: negative group (14.24±7.72)%, positive group (15.82±9.13)%, (P > 0.05); Erythrocyte series rate in bone marrow negative group (49.27±13.55)%, positive group (51.16±15.60)%, (P > 0.05). (3) Etiology:negative group: infection takes up 22.73%, 18.18% has a history of taking special drugs.4.55% has rheumatic disease. 4.55% was diagnosed as MDS with autoimmune phenomenon, secondary AIHA takes up 50%. Positive group: infection takes up 20.51%, 5.13% has a history of taking special drugs. 14.10%was clearly diagnosed as autoimmune disease, secondary AIHA takes up 43.50%. Comparison was made between these rates, and drug-induced AIHA and autoimmune disease has great obvious difference (P<0.005). (4) Response to treatment: negative group: 13.64% were treated with high-dose glucocortcoid, 86.36% got CR, 13.64% relapsed; positive group: 25.64% were treated with high-dose glucocortcoid, 69.23% got CR. 26.92% relapsed, death rate was 2.56%, Comparison was made between these rates, and CR rate has great obvious difference between two groups (P<0.005), relapse rate and rate of using high dose glucocortcoid has obvious difference (P < 0.05). One day after treatment with glucocortcoid, RBC and Hb in negative group got forward increasment; however three days after the same treatment, positive group got forward increasment,but the growth fraction on 6th,7th,10th day has no difference between two groups.Conclusion: 1. The incidence of female is higher than that of male in Coombs- negative AIHA. 2. Both hemolytic degree and anemia degree in Coombs-negative AIHA is less than those of Coombs-positive AIHA. 3 .Secondary AIHA takes up 50% in Coombs-negative AIHA, and infection, drug-induced and autoimmune disease were the first three etiology by turns;Secondary AIHA takes up 43.50% in Coombs-positive AIHA, and infection, autoimmune disease and drug-induced were the first three etiology by turns. The rate of drug-induced AIHA in negative group is higher than that in positive group, however, AIHA secondary to autoimmune disease is higher in positive group than that in negative group. 4. CR rate in negative group is much higher than that in positive group, and relapse rate and rate of using high dose glucocortcoid is lower than that in positive group, negative group received better response to glucocortcoid. 5. The degree of the symptom in Coombs-negative AIHA is lower than that in Coombs-positive AIHA, likely secondary to temporal immune disorders such as infection, drug-induced and so on. Coombs-negative AIHA may not last for a long time, and response well to glucocortcoid, and the prognosis is good. 6.The reason why coombs is negative may be test is not enough precise.