However, it was acknowledged early from these studies [18] that for hypogammaglobulinaemic subjects, the half-life was, in some cases, longer than this interval. A few bio-markers for assessing clinical and immunologic status have been proposed, and some have proved to be useful, but additional methods to gauge the benefits of therapy, predict outcomes, and harmonize treatment practices are needed. Aside from Ig replacement, additional means of prevention of lung disease may need concern to reduce lung damage apart from prophylactic antibiotics. These might include using macrolides as anti-inflammatory brokers, inhaled corticosteroids, bronchodilators, mucolytics or mechanical or rehabilitative respiratory methods. Keywords: antibody deficiency, immune globulin, contamination, lung disease Introduction Replacement immune globulin therapy is the mainstay of treatment of subjects with insufficient production of immune globulins due to either genetic or secondary failure of B cell development. For subjects with congenital failure of antibody production, replacement Amsacrine immune globulin, given at punctual intervals, is the standard of care, and it has revolutionized the lives of these patients. While some congenital immune defects do not require the use of immune globulin, about 70% of the known defects lead to a lack of antibody and require antibody replacement. While many publications in the past 25 years have described the use of immunoglobulin in main immune deficiency, additional questions remain about some of the most basic concepts of this therapy. Some of these are discussed here. Serum immune globulins (Ig) treatment and lung disease Sufficient immune globulin replacement has been shown to reduce systemic bacterial infections significantly in subjects with main immune defects. In a study in common variable immune deficiency (CVID), 42 of 50 consecutively referred subjects (84%) Amsacrine experienced at Spry4 least one episode of pneumonia prior to starting treatment. After intravenous immune globulin was started, only 11 of the 50 (22%) experienced additional episodes of pneumonia, representing a clear reduction (= 001) [1]. These data are similar to another statement in CVID in which 629% of patients experienced experienced pneumonia prior to the acknowledgement of immune deficiency, but only 205% experienced pneumonia after this diagnosis was made [2]. It was acknowledged quite early that Ig replacement in X-linked agammaglobulinaemia (XLA) and CVID also led to reduced hospitalizations [3,4]. Other studies have shown the benefits of Ig replacement in subjects with IgG subclass defects, resulting in fewer infections [5]. While systemic bacterial infections such as sepsis and meningitis are clearly more rare in patients who receive sufficient Ig treatment, some of the more common infections still remain a clinical problem, including sinusitis, bronchitis and an occasional instance of pneumonia. Of more concern is the progression of lung disease in some subjects who receive what is considered standard Ig replacement therapy. High-resolution computerized tomography showed that progression of lung disease can occur in subjects with at least 500 mg/dl serum IgG [6]. In addition, bronchial lavage samples of patients with bronchiectasis, fibrosis and/or emphysema revealed that both bacteria (mainly noted that, for 224 subjects on standard Ig replacement, followed over a mean time of 11 years, 342% experienced a history of chronic lung disease at diagnosis [based on high-resolution hypocretin] but 463% experienced this diagnosis at follow-up. Furthermore, bronchiectasis was found in 56 patients at diagnosis, but in 65 at the most recent encounter [2,8]. Because of these issues, some studies have addressed the question of the optimum dose of Ig to use in order to prevent ongoing lung damage. Roifman proven that 600 mg/kg was far better than 200 mg/kg in avoiding lung impairment [9], illustrating Amsacrine the advantage of the higher dosage, however the lower dose found in this research will be be looked at insufficient by current guidelines [10] generally. Eijkhout showed that looking at adult individuals also.