In autoimmune diseases the production of auto reactive antibodies is related to activation of normal B-lymphocytes. The high incidence of autoimmune disorders (AID) in CLL is well known, but the origin of auto antibodies is controversial. In the present study we postulate that Chronic Lymphocytic Leukemia associated with autoimmune diseases discloses activated phenotype pattern.
Out of the 891 CLL patients registered in the Israeli Study Group, we found 72 patients (8%) who presented at least one clinically expressed autoimmune disease at diagnosis.
Median age was 67 years old (range 45–87). 44% were male, 45 patients were at Binet`s stage A, 17 patients at Stage B and 4 at Stage C, and six patients were diagnosed with de novo PLL. The autoimmune disorders were as follows: Hashimoto`s disease (25), AIHA (11), Sjogren`s syndrome (10), rheumatoid arthritis (9), vasculitis (8), Grave’s disease (5), Evan’s syndrome (4), ITP (4), multiple sclerosis (2) and pernicious anemia, pure red cells aplasia, Raynaud`s syndrome, systemic erythematous lupus, ulcerative colitis (each-one). We found also 19 cases of positive direct antiglobulin test, 7 cases of positive rheumatoid factor, 4 cases with positive antinuclear antibodies, and 7 cases of hypocomplementemia. In 16 patients (22%) the morphology cell was consistent with activated lymphocytes (more than 30% of prolymphocytes). Immunophenotype analysis revealed increased expression (>30%) of activation markers CD38 or FMC7 in 27%. IgG was higher than 1000 mg/dl in 57%, while 5 cases found with IgM paraproteinemia.
Increased Beta2- microglobulin level, described by us correlating the activation of B-CLL cells, was increased in 78% of tested cases. The new marker ZAP 70 analyzed in seven patients and found positive in 5. Interestingly, Beta2m and CD38 wich usually define agressive disease were found predominatly in stage A patients with AID.
Our results suggest that in B- CLL associated with autoimmune disorders, the B CLL cells present some degree of activation. It is well known that B-lymphocytes in CLL are in a preactivated state and can be induced to differentiate into plasma cells and to stimulate residual normal B cells to produce high-affinity polyclonal autoantibodies with restricted specificity and pathogenic properties. This possibility would be in keeping with our observation.
Conclusion: our data showing activated lymphocytes morphology and /or increased expression CD38 or FMC7, high level of IgG and of Beta2-m in most of the cases, suggests that a state of activation of B-cells may correlate with the occurrence of autoimmune complication in B-CLL.