Enfermedad relacionada a IgG4. Serie clínica de pacientes chilenos / IGG4-related disease. Report of 52 patients

BACKGROUND: IgG4-related disease (IgG4 RD) is an immune-mediated fibro-inflammatory disorder, with tissue infiltration of IgG4+ plasma cells. It causes pseudotumors, tumors, and a wide spectrum of clinical manifestations. AIM: To report the clinical, laboratory, histopathological and treatment characteristics of a group of Chilean patients with IgG4 RD. MATERIAL AND METHODS: Review of medical records of 52 patients aged 18 to 76 years with IgG4 RD seen at six medical centers. RESULTS: Elevated IgG4 serum levels (> 135 mg/dl) were found in 18 of 44 (41%) patients. There was histological confirmation of the disease in 46 patients. The most common sites of involvement were lungs, eyes and kidneys. Eighteen (35%) patients had only one organ involved, 34 (65%) patients had two organs and 13 (25%) patients had three or more organs. The involvement of two organs was significantly more common in men (p < 0.05). In patients with only one organ involvement, the most frequent location was orbital and meningeal. All patients with kidney or lung disease had multiorgan involvement. All patients received corticosteroid therapy, 67% synthetic immunosuppressants, and 16% rituximab. CONCLUSIONS: ER-IgG4 can affect any tissue. Multiorgan involvement was more common in this series, with preference for lungs, eyes and kidneys. An excellent response to steroids is characteristic of the disease, but with a high relapse rate that requires additional immunosuppression.

Compromiso óseo en mastocitosis sistémica: una asociación frecuente, pero muchas veces inadvertida / Bone involvement in systemic mastocytosis: report of two cases

Systemic mastocytosis (SM) is characterized by pathologic expansion and activation of mast cells. The main clinical manifestations of SM include skin involvement, gastrointestinal symptoms and anaphylaxis due to the release of its mediators. Thirty percent of pat ients with SM have a low bone mass and 20% fractures. At the same time, SM affects 10% of male patients with idiopathic osteoporosis. Measuring serum tryptase is essential for the screening of MS. We report two cases of SM with bone involvement. A 25-year- old woman with prior diagnosis of SM, based on skin involvement, flushing, high serum tryptase and compatible bone marrow (BM) biopsy and genetic study. Low bone mass was diagnosed and treatment was started with calcium and vitamin D plus oral bisphosphona tes with adequate response. A 47 years old man who presented with multiple osteoporotic vertebral fractures and low bone mass. Treatment with vitamin D and alendronate was started, but the patient developed new vertebral fractures. The study was extended w ith measurement of serum tryptase that was elevated. Diagnosis of SM was confirmed with BM biopsy and the patient was referred to hematology for specific care. These cases emphasize the importance of bone assessment in SM, as well as the need to rule out S M in patients with osteoporosis and no evident cause.

Autoanticuerpos anti-galectina-8 en pacientes con lupus eritematoso sistémico / Antibodies against galectin-8 in patients with systemic lupus erythematosus

Background: The family of lectins known as galectins (galectins 1-14) are involved in the regulation of the immune system and in oncogenesis. During a search for antigens recognized by antibodies produced by a patient with systemic lupus erythematosus (SLE) we found reactivity against galectin-8, for which autoantibodies have not been previously described. Aim: To determine the frequency of autoantibodies against galectin-8 in lupus patients compared with healthy controls. Patients and Methods: Galectin-8 was purified from a bacterial expression system and used in immunoblot assays as antigen to screen the sera of 55 SLE patients and matched controls. Disease activity was evaluated using the Mexican Modification of the Systemic Lupus Erythematosus Disease Activity Index (MEX-SLEDAI). Results: Reactivity against galectin-8 was detected in 30% of SLE patients, compared to 7% of controls (p=0.003). We could not detect any particular SLE manifestation associated to the presence of these autoantibodies. Conclusions: This is the first description of autoantibodies against galectin-8. Its higher frequency in patients with SLE suggests a pathogenic role. Further studies are needed to determine their clinical relevance.