Association of FcRn expression with lung abnormalities and IVIG catabolism in patients with common variable immunodeficiency.

The neonatal Fc receptor (FcRn) acts as a key regulator of IgG homeostasis and is an important sensor of luminal infection. We analyzed the influence of FcRn expression on disease phenotype and the catabolism of therapeutically administered intravenous immunoglobulins (IVIG) in 28 patients with common variable immunodeficiency (CVID). Patients with generalized bronchiectasis and fibrosis had lower levels of FCRN mRNA compared to patients without these complications (P=0.027 and P=0.041, respectively). Moreover, FCRN mRNA levels correlated negatively with the extent of bronchiectasis and the rate of IgG decline after infusion of IVIG (P=0.027 and P=0.045, respectively). No relationship of FCRN expression with age at disease onset, age at diagnosis, diagnostic delay, IgG levels or frequency of infections before or during replacement immunoglobulin treatment, the presence of lung functional abnormalities, chronic diarrhea, granulomas, lymphadenopathy, splenomegaly or autoimmune phenomena was observed. Our results showed that FcRn might play a role in the development of lung structural abnormalities and in the catabolism of IVIG in patients with CVID.

[Iris metastasis as the first sign of small-cell lung carcinoma with metastatic involvement of the mediastinum]. / Duhovková metastáza jako iniciální manifestace bronchogenního malobunecného karcinomu diseminovaného do mediastina.

BACKGROUND: We present the case of small-cell lung carcinoma metastatic to the iris, the course of the disease and management options. CASE: A 69-year-old female was diagnosed with a solid, amelanotic iris mass in her left eye. Differential diagnostics and ancillary tests subsequently led to the diagnosis of disseminated small-cell lung carcinoma. Systemic chemotherapy was indicated after fine needle biopsy verification of metastatic lung cancer. Iris metastasis responded well to the chemotherapy, its regression was observed and secondary open-angle glaucoma was controlled as well. Good visual functions were preserved during the treatment. CONCLUSIONS: Metastatic carcinoma of the iris may be the first sign of disseminated malignant disease. Small-cell lung carcinoma iris metastasis can be treated with chemotherapy. This treatment preserved visual functions, which enhanced the patient's quality of life.

Mannose-binding lectin gene polymorphic variants predispose to the development of bronchopulmonary complications but have no influence on other clinical and laboratory symptoms or signs of common variable immunodeficiency.

Mannose-binding lectin (MBL), activating protein of the lectin pathway of the complement system, is an important component of the non-specific immune response. MBL2 gene polymorphisms, both in the coding and promoter regions, lead to low or deficient serum MBL levels. Low serum MBL levels were shown to be associated with serious infectious complications, mainly in patients in whom other non-specific immune system barriers were disturbed (granulocytopenia, cystic fibrosis). We have analysed two promoter (-550 and -221) and three exon (codons 52, 54 and 57) MBL2 polymorphisms in a total of 94 patients with common variable immunodeficiency (CVID) from two immunodeficiency centres. Low-producing genotypes were associated with the presence of bronchiectasis (P = 0.009), lung fibrosis (P = 0.037) and also with respiratory insufficiency (P = 0.029). We could not demonstrate any association of MBL deficiency with age at onset of clinical symptoms, age at diagnosis, the number of pneumonias before diagnosis or serum immunoglobulin (Ig)G, IgA and IgM levels before initiation of Ig treatment. No association with emphysema development was observed, such as with lung function test abnormalities. No effect of MBL2 genotypes on the presence of diarrhoea, granuloma formation, lymphadenopathy, splenomegaly, frequency of respiratory tract infection or the number of antibiotic courses of the patients was observed. Our study suggests that low MBL-producing genotypes predispose to bronchiectasis formation, and also fibrosis and respiratory insufficiency development, but have no effect on other complications in CVID patients.