Multifactorial immunodeficiency in frail elderly patients: Contributing factors and management.

Immunodeficiency in the elderly is multifactorial. The analysis of etiological factors demonstrates the major role of immunosenescence and protein-energy malnutrition (PEM) with high prevalence deficiencies in micronutrients such as vitamin D, zinc, or vitamin E in people aged above 75 years. PEM contributes to the numerous consequences of frailty syndrome, and mainly to susceptibility to infections including fungal infections, which are usually observed in immunodeficient patients. Particular attention should thus be paid to these patients. However, these peculiarities of the immune system aging and the aging-related vulnerability can lead to diagnostic delays and treatment escalation, mainly with antibiotics, as well as to a loss of time resulting in a loss of opportunity for patients. Antibiotic escalation also leads to microbiological selection pressure in frail elderly people, which can be deleterious in the long-term in case of opportunistic infections. Guidelines are mainly based on the identification and management of frailty, especially in terms of nutrition. The identification of nutritional risk, dietary management, mood vigilance, and a functional approach are the four pillars of the management strategy. These elements are part of a global geriatric assessment and care.