Paucity of splenic germinal centers: a new and unique splenomegaly syndrome including dysfunctional immune system

Autoimmune lymphoproliferative syndrome: etiology, diagnosis, and management

Autoimmune lymphoproliferative syndrome (ALPS) is a childhood disorder characterized by chronic, nonmalignant lymphoproliferation and autoimmunity, most commonly involving cells of hematopoietic origin. Mutations of the tumor necrosis factor receptor super family member 6 (TNFRSF6) gene, coding for the apoptosis-inducing protein Fas (Apo-1, CD95) are involved in the physiopathology of the syndrome, although the complete mechanism by which the syndrome is caused has not yet been unraveled. Although the syndrome has a benign nature, life-threatening complications can demand treatment. Treatment schedules, including corticosteroids, low doses of chemotherapy, granulocyte colony stimulating factor, or splenectomy, have varying results. Treatment with the antimalarial drug pyrimethamine/sulfadoxine (25/500mg per tablet) seems to be a new, well tolerated, and efficient approach, although larger studies will have to demonstrate the true value of this drug in patients with ALPS.

The clinical spectrum in a large kindred with autoimmune lymphoproliferative syndrome caused by a Fas mutation that impairs lymphocyte apoptosis

Autoimmune lymphoproliferative syndrome (ALPS) is characterized by chronic, histologically benign splenomegaly and generalized lymphadenopathy, hypergammaglobulinemia, and autoantibody formation. ALPS has been attributed to defective programmed cell death of lymphocytes, most often arising as a result of mutations in the gene encoding the lymphocyte apoptosis receptor Fas/APO-l/CD95. We identified a novel mutation in the intracellular apoptosis signaling domain of Fas in 11 members of a family, individual members of which have been monitored for up to 25 years, with 1 or more features of ALPS. This study of a large number of family members carrying the same Fas defect demonstrates that ALPS is inherited in an autosomal dominant fashion but with a high degree of variability in clinical expression. Although 1 affected individual died of postsplenectomy sepsis and 1 has been treated for lymphoma, the Fas mutation in this family has been compatible with a healthy adulthood, as clinical features of ALPS have receded with increasing age.

The disappearance of germinal centers in chronic lymphadeno-hepato-splenomegaly syndrome in childhood: report of three cases

Three cases of a syndrome featuring massive splenomegaly, gross generalized lymphadenopathy, and moderate hepatomegaly are reported. Spleen weights ranged from 800 to 2400 g. Gradual depletion of lymphoid germinal centers, and prominent infiltration of the splenic and lymph node cords with plasma cells, immunoblasts and actively dividing B cells were the most distinctive histological features. The liver in two cases showed portal infiltrates. A marked hypergammaglobulinemia, a decrease in blood cholesterol level and hematological abnormalities related to hypersplenism were observed. The condition begins early in life and runs a chronic course, of up to 25 years. There was a family history in only one instance. Since there was no generalized immunodeficiency nor local depletion of T cells or dendritic reticulum cells, a failure in the local regulation of the immune response and possible cytokine production is postulated. This condition underlines the pivotal role of the local organization of the germinal centers in cellular cooperation and in the carrying out and regulation of the immune response.

Familial splenomegaly syndrome with reduced circulating T helper cells and splenic germinal centre hypoplasia

Familial splenomegaly is a rare occurrence and is occasionally associated with immune abnormalities. We report three members of a family with massive splenomegaly associated with a reduction in circulating T helper cells, a reversed T4/T8 ratio and cutaneous anergy. The spleen and lymph nodes were shown in one family member to have germinal centre hypoplasia with T helper cells being present in normal numbers and distribution in these tissues. Various abnormalities of immunoglobulins were also noted. Despite the demonstrated immune abnormalities, the affected subjects showed few serious consequences. The pathogenesis of this disorder is unclear but we postulate it may involve a functional defect of the T helper cell. This defect probably is responsible both for the diminished circulating capacity of T helper cells as well as a reduced ability to aid in the formation of germinal centres.