Role of polymorphisms of the inflammatory response genes and DC-SIGNR in genetic susceptibility to SARS and other infections

1. A genetic risk-association study involving more than 1200 subjects showed individuals homozygous for L-SIGN tandem repeats are less susceptible to SARS infection. 2. This was supported by in vitro binding studies that demonstrated homozygous L-SIGN, compared to heterozygous, had higher binding capacity for SARS coronavirus (SARS-CoV), with higher proteasome-dependent viral degradation. In contrast, homozygous L-SIGN demonstrated lower binding capacity for HIV1-gp120.3. Genetic-association studies for single nucleotide polymorphisms of the inflammatory response genes, namely TNF-alpha, INF-alpha, INF-beta, INF-gamma, IL1-alpha, IL1-beta, IL-4, IL-6 and iNOS, failed to show a significant association with SARS clinical outcomes or susceptibility.

Inability of physicians to use metered-dose inhalers

The effectiveness of antiasthmatic therapy with metered-dose inhalers (MDIs) is usually limited by defective inhalational technique. This study surveyed the MDI inhalation performance and knowledge of 100 physicians whose performance (demarcated into six stages) and knowledge scores correlated (r = 0.33, p < 0.001). Inhalation performance scores for shaking the canister, full expiration prior to using the MDI, breath holding thereafter, and positioning of the mouth-piece correlated with their corresponding knowledge scores (p < or = 0.02). Training of physicians entailing actual instruction and supervision of inhalational maneuvers may enhance the ability of doctors to use MDIs and facilitate better patient supervision.

Decreased bone mineral density in premenopausal asthma patients receiving long-term inhaled steroids

Inhaled corticosteroids have become a key element in the maintenance treatment of bronchial asthma. It is well-known that long-term systemic steroid use causes osteoporosis, whereas its inhaled counterpart has been believed to be devoid of such a side-effect. However, recent studies showed that administration of inhaled corticosteroids was associated with biochemical evidence of derangement in bone turnover. We therefore studied bone mineral density (BMD) by dual energy x-ray absorptiometry in 30 patients (18 females, 12 males) with bronchial asthma treated with steroids, essentially by the inhaled route only (both nasal and tracheobronchial), and compared them with healthy subjects individually matched for age, sex, menopausal status, and body mass index (BMI). There was a significant decrease in BMD in the patient group at the hip (neck of femur, p = 0.007; trochanter of femur, p = 0.034; Ward's triangle, p = 0.016) and the lumbar area of the spine (L2-4, p = 0.041). Further analysis showed that this difference from control subjects was mainly seen in the female patients and not in the male patients (neck of femur, p = 0.049; Ward's triangle, p = 0.025; lumbar spine, p = 0.039). In the female patients, there was significant negative correlation of BMD of the lumbar area of the spine and the trochanter of femur with daily inhaled steroid dose and positive correlation of BMD of the trochanter with BMI.

High prevalence of asthma in patients with bronchiectasis in Hong Kong

Eighty five Chinese patients with diffuse or localized bronchiectasis (non-cystic fibrosis) were studied regarding the prevalence of asthma. Twenty three of the 85 had concomitant asthma, diagnosed by history and reversibility on lung function testing either spontaneously or after bronchodilator. None fulfilled the diagnostic criteria of allergic bronchopulmonary aspergillosis (ABPA). Asthma preceded the onset of bronchiectasis in 13 patients and developed after long duration of bronchiectasis in seven, while the temporal onset could not be differentiated in three patients. Patients with both asthma and bronchiectasis had inferior spirometric values, higher prevalence of bronchial hyperresponsiveness to methacholine, higher prevalence of skin atopy, elevated serum immunoglobulin E (IgE), and more sputum eosinophilia, compared with their non-asthmatic counterparts. Possible mechanisms by which asthma and bronchiectasis predispose to each other include asthmatic obstruction contributing to development of bronchiectasis, and sensitization of airways with increased lability due to microbial colonization of the ectatic bronchial tree.

High prevalence of asthma in patients with bronchiectasis in Hong Kong

Eighty five Chinese patients with diffuse or localized bronchiectasis (non-cystic fibrosis) were studied regarding the prevalence of asthma. Twenty three of the 85 had concomitant asthma, diagnosed by history and reversibility on lung function testing either spontaneously or after bronchodilator. None fulfilled the diagnostic criteria of allergic bronchopulmonary aspergillosis (ABPA). Asthma preceded the onset of bronchiectasis in 13 patients and developed after long duration of bronchiectasis in seven, while the temporal onset could not be differentiated in three patients. Patients with both asthma and bronchiectasis had inferior spirometric values, higher prevalence of bronchial hyperresponsiveness to methacholine, higher prevalence of skin atopy, elevated serum immunoglobulin E (IgE), and more sputum eosinophilia, compared with their non-asthmatic counterparts. Possible mechanisms by which asthma and bronchiectasis predispose to each other include asthmatic obstruction contributing to development of bronchiectasis, and sensitization of airways with increased lability due to microbial colonization of the ectatic bronchial tree.

Splenectomy in hematologic malignancy

Fifty patients undergoing splenectomy for complications of hematologic malignancy were reviewed to define indications and results. Primary diseases included lymphoma (n = 14), chronic lymphatic leukemia (n = 13), hairy-cell leukemia (n = 12), myeloid metaplasia (n = 6), and other similar disorders (n = 5). Indications for splenectomy in these patients included cytopenia (n = 37), diagnostic laparotomy (n = 8), "small stomach" syndrome (n = 3), and abdominal pain (n = 2). Splenectomy was performed by the midline approach in 32 patients. In 40 patients, the splenic artery was ligated prior to mobilization of the spleen. The spleens averaged 1650 g; in eight patients accessory spleens were removed. Additional surgical procedures included liver biopsy (n = 30), lymph node biopsy (n = 15), and cholecystectomy (n = 3). Intraoperative blood loss averaged 750 ml. In 14 patients, drainage of the left subphrenic space was used. Splenectomy was effective in 36 of 50 patients. In seven patients, splenectomy was ineffective in correction of cytopenia. Seven mortalities were from bleeding (n = 2), pulmonary embolus (n = 2), postoperative sepsis (n = 2), and progression of primary disease (n = 1). Additional complications included reoperation for bleeding (n = 3), septic complications including pneumonia (n = 14), wound infection (n = 4), and intra-abdominal abscess (n = 2). Splenectomy for the patients with hematologic malignancy is generally effective. Meticulous hemostasis, timely administration of intraoperative platelets, surgical asepsis, and aggressive pulmonary care are essential to reduce morbidity and mortality.