Immunoglobulin G subclass deficiency has been diagnosed in 25% of patients presenting with recurrent infections. Similar to other primary immunodeficiencies, it is commonly overlooked or misdiagnosed. The diagnosis includes documentation of a decreased level of one or more subclasses in conjunction with an inadequate response to a vaccine challenge. Understanding the specific actions of the four subclasses allows the clinician to direct the evaluation and define a treatment program. Several subclass deficiencies are also associated with other disease states. Diagnosis of this entity will limit patient morbidity and allow for more rapid identification of other potentially life-altering illnesses.

Specific antibody deficiency was previously known as selective antibody deficiency with normal immunoglobulins (SADNI). The diagnosis of SAD depends on normal immunoglobulin and IgG subclass levels, as well as a normal reaction to protein-based and conjugate vaccinations. The only immunologic deficiency in patients with SAD is an abnormal response to polysaccharide antigens, as found in the PPV23, known as the twenty-three valent pneumococcal vaccine.

It has been twenty-five years since antiretroviral therapy (ART) for human immunodeficiency virus (HIV) became available. This review summarizes clinical data for the established 2DRs and explores some of the remaining questions and concerns about these regimens.

Patients with COVID-19 pneumonia on mechanical ventilation can exhibit clinical signs difficult to distinguish from ventilator-associated pneumonia (VAP). Positive sputum cultures in these patients often lead to the use of broad-spectrum antibiotics.

Septic arthritis (SA) is an uncommon but potentially life-threatening condition; it occurs when microorganisms invade the joint space by direct inoculation or by hematogenous spread..

Osteomyelitis is, by definition, inflammation of the bone and the bone marrow that can be secondary to bacteria, mycobacteria, or fungi.