What’s new in May for Scientific American™ Medicine features:

– Secukinumab

– Identification of the Causative Organism

– The Changing Role of Aminoglycosides: Tobramycin

– Prognosis of Rheumatoid Arthritis.

tid1328_fig1.jpg

Antigen (Ag)–major histocompatibility complex (MHC) recognition by T cell receptor controls T cell survival and activation

 

ALLERGY & IMMUNOLOGY

Introduction to Clinical Immunology: Overview of the Immune Response, Autoimmune Conditions, and Immunosuppressive Therapeutics for Rheumatic Diseases

STEVEN K. LUNDY, PhD

Division of Allergy & Immunology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX

ALISON M. GIZINKI, MD

Division of Allergy & Immunology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX

DAVID A. FOX, MD

Division of Rheumatology, Department of Internal Medicine, University of Michigan Medical School and Health System, Ann Arbor, MI

 

Secukinumab

Interleukin (IL)-17A is the most important isoform of IL-17, and a monoclonal antibody that neutralizes this cytokine, secukinumab, has recently been FDA approved for use in psoriasis, psoriatic arthritis, and ankylosing spondylitis. IL-17 is important in host defense against Candida and some bacteria, and vigilant monitoring for infections is important in patients who receive either this antibody or other biologics. Neutralization of IL-17 has been reported to aggravate inflammatory bowel disease, and exacerbations of Crohn disease were seen in patients receiving secukinumab.

 


 

tid1475_fig1.png

Sites of action for major antibiotic classes

 

INFECTIOUS DISEASES

General Principles of Antibiotic Therapy

Alyssa R. Letourneau, MD, MPH

Michael S. Calderwood, MD, MPH

Department of Medicine, Harvard Medical School, Antimicrobial Stewardship, Brigham and Women’s Hospital, Boston, MA

 

Identification of the Causative Organism

Prompt identification of the causative organism is essential for the selection of an appropriate antibiotic. A Gram stain of infected body fluids can provide early clues to the etiologic agent. In addition, immunodiagnostic tests and polymerase chain reaction testing may provide rapid identification of the infecting organism. Another technology that is improving the time to identifying the cause of an infection is matrix-assisted laser desorption/ionization–time of flight (MALDI-TOF). In addition, many medical facilities are using biomarkers (e.g., procalcitonin) to help determine whether a patient’s presenting complaints have an underlying bacterial etiology, particularly in cases of respiratory tract infection.

 


 

Tobramycin_1lc4.jpg

Stick model of tobramycin

 

INFECTIOUS DISEASES

Specific Antibiotic Agents

Alyssa R. Letourneau, MD, MPH

Michael S. Calderwood, MD, MPH

Department of Medicine, Harvard Medical School, Antimicrobial Stewardship, Brigham and Women’s Hospital, Boston, MA

 

The Changing Role of Aminoglycosides: Tobramycin

Gentamicin and tobramycin have similar spectra of activity, except tobramycin is more active against Pseudomonas aeruginosa. The inhaled administration of tobramycin has gained popularity among specialists who treat patients with chronic P. aeruginosa lung infection, including patients with cystic fibrosis. This novel approach may decrease toxicity while increasing the concentration of drug in the airways; however, the potential for toxicity remains, cases of bronchospasm have been reported, and clinical experience outside of bronchiectatic lung disease is limited. Therefore, this practice is not recommended for general use.

 


tid1011_fig1

Variations in the temporal course and severity of pain in the rheumatic diseases

 

RHEUMATOLOGY

Introduction to the Patient with Rheumatic Disease

DAVID A. FOX, MD

Division of Rheumatology, Department of Internal Medicine, University of Michigan Medical School and Health System, Ann Arbor, MI

 

Prognosis of Rheumatoid Arthritis

Most kinds of arthritis can be managed effectively, and the patient must understand that treatment greatly improves the condition of most patients with arthritis. Even for the most severe diseases, such as rheumatoid arthritis, very effective treatments are available and have brought distinct improvements in long-term outcome. New treatments with biologic agents that block inflammatory cytokines, such as tumor necrosis factor, or alter the function of autoreactive lymphocytes are very effective, have a rapid onset of action, and prevent radiographic progression of the disease. Educating the patient about the effectiveness of treatment is the first step toward a successful outcome.

 


 

As seen in Scientific AmericanTM Medicine.