A case of mixed type autoimmune hemolytic anemia and immune thrombocytopenic purpura preceding primary Sjögren's syndrome

Abstract

Immune thrombocytopenic purpura (ITP) is infrequent complication and autoimmune hemolytic anemia (AIHA) is, furthermore, a rare occurence in primary Sjögren's syndrome (SjS). This paper reports the first case of SjS associated with both mixed type AIHA and ITP. A 16-year-old female was admitted because of malaise, petechia and nasal bleeding. Laboratory studies revealed anemia (RBC 182×10⁴/μl, hematocrit 17.5%, hemoglobin 5.9g/dl) and thrombocytopenia (platelet 2.7×10⁴/μl). Remarkable agglutination of erythrocytes was seen in blood smear. On bone marrow examination, there was no particular finding except for slight increase of erythroid cells. The serum indirect bilirubin was 4.6mg/dl. The lactic dehydrogenase was elevated. The haptoglobin was less than 10mg/dl. The PAIgG was increased. The titers of antibodies to several viruses and mucoplasma were normal. Direct and indirect Coombs tests were positive for anti-IgG, IgM and C 3 d antisera. The cold agglutinin, identified as IgM, reacted with I-antigen positive erythrocytes with thermal amplitude from 4°C to 37°C. These findings elucidated that hemolysis is caused by both warm and cold autoantibodies. Wassermann's reaction was biologically false positive. However, the concerining of lupus anticoagulant was excluded by cross mixing test and dilute tissue thromboplastin test. The AIHA and ITP were satisfactorily subsided by steroid therapy. Three years later, the patient noticed knee pain and parotid swelling. Any deterioration was not found in peripheral blood. Pathological findings of minor salivary gland was consistent with SjS. The double stain procedure, using monoclonal antibodies, disclosed the reduced proportion of suppressor-inducer T cells (CD 4⁺CD 45 R⁺) and increased proportion of suppressor T cells (CD 8⁺CD 11⁺) in peripheral blood. Frequencies of CD 3⁺, CD 4⁺ and CD 8⁺ T cells were similar as compared with those at the onset of AIHA and ITP. Mantoux's test was negative through the course. These findings suggested that the aberration of suppressor T cells, probably based on subclinical SjS, caused mixed AIHA and ITP and subsequently allowed SjS to appear.