Background and Importance Human immunoglobulins (HI) are essential for treatment of primary immunodeficiency (PI). They are also used for other conditions, some of which do not have very high evidence or have therapeutic alternatives other than HI. Given the current shortage of HI, careful consideration of its indications and administration is warranted.

Aim and Objectives I)To describe the use of HI of an adult population treated in a tertiary university hospital (767 beds), which is a reference hospital for PI and other minority pathologies. II)To identify those indications for which the use of HI has a low level of evidence according to the national guidelines.

Observational retrospective study No intervention. All patients who received HI during 1/1–31/12, 2022 were included. Data was obtained from electronic medical records.

Results A total of 104786g of HI were administered to 432 patients (52.3% women). Median age and weight were 60.0 years (IQR:45.0–71.3) and 68.0kg (IQR:59.0–80.0), respectively. Seventy patients (16.2%) had a BMI >30kg/m². Two hundred eleven patients (48.8%) received HI for the first time. There were 209 (48.4%) long-term HI treatments (minimum three-month duration) and 224 (51.6%) short-term treatments.

Only 13200g of HI (12.6%) were administered to 134 inpatients. High number of patients (85.2%) received intravenous HI, consuming 87495g (83.5%). The indications with the highest consumption of HI were immunomodulatory treatment of dermatomyositis and other inflammatory myopathies (4.9% and 4.6% of patients; 19,2% and 10.0% of consumption, respectively) and replacement therapy in common variable immunodeficiency (11.1% of patients, 10.0% of consumption). HI were prescribed from 12 different specialties, with internal medicine, neurology and hematology being the most, with 32.5%, 15.8% and 15.4% of total consumption, respectively.

An 8.3% of total HI consumption was administered to 33 patients (7.6%) with indications with low evidence of HI efficacy. Of these indications, the most common were BK virus nephropathy in kidney transplant patients (n=5), autoimmune dermatological diseases (n=5), severe myocarditis (n=3) and autoimmune haemolytic anaemias (n=3).

Conclusion and Relevance HI are widely used by multiple specialties. HI for low-evidence indications are used in a low, but not minimal, percentage. These uses must be reviewed by a multidisciplinary team in order to optimise the prescription of HI.

Conflict of Interest No conflict of interest.