Economic burden of congenital athymia in the United States for patients receiving supportive care during the first 3 years of life

AIMS

Congenital athymia is an ultra-rare pediatric condition characterized by the lack of thymus in utero and the naïve T cells critical for infection defense and immune regulation. Patients with congenital athymia receive supportive care to minimize and treat infections, autoimmune phenomena, and autologous graft-versus-host disease (aGVHD) manifestations, but historically, die within the first 3 years of life with supportive care only. We estimated the healthcare resource utilization and economic burden of supportive care over patients' first 3 years of life in the United States.

METHODS

A medical chart audit by the treating physician was used to collect patient data from birth to age 3 on clinical manifestations associated with congenital athymia (clinical manifestations due to underlying syndromic conditions excluded). Using costs and charges from publicly available sources, the total economic burden of direct medical costs and charges for the first 3 years of life (considered "lifetime" for patients receiving supportive care) and differences in economic burden between patients with higher and lower inpatient hospitalization durations were estimated.

RESULTS

All patients (n = 10) experienced frequent infections and aGVHD manifestations; 40% experienced ≥1 episode of sepsis, and 20% had recurrent sepsis episodes annually. The estimated mean 3-year economic burden per patient was US$5,534,121 (2020 US dollars). The annual mean inpatient hospitalization duration was 150.6 days. Inpatient room charges accounted for 79% of the economic burden, reflecting the high costs of specialized care settings required to prevent infection, including isolation. Patients with high inpatient utilization (n = 5; annual mean inpatient hospitalization duration, 289.6 days) had an estimated 3-year economic burden of US$9,926,229.

LIMITATIONS

The total economic burden may not be adequately represented due to underestimation of some direct costs or overestimation of others.

CONCLUSIONS

Current treatment of patients with congenital athymia (supportive care) presents a high economic burden to the healthcare system.

Increased spontaneous apoptosis in T lymphocytes in DiGeorge anomaly

The aim of this study was to determine whether increased apoptosis in peripheral blood lymphocytes plays a role in T cell deficiency associated with DiGeorge anomaly. T cell subsets from a patient with DiGeorge anomaly were examined for the expression of Fas, FasL, Bcl-2 and Bcl-XL at the protein level with monoclonal antibodies, using dual-colour flow cytometry, and at the mRNA level in mononuclear cells by quantitative reverse transcriptase-polymerase chain reaction. In vitro spontaneous apoptosis was examined by propidium iodide staining and DNA fragmentation, using flow cytometry and gel electrophoresis, respectively. Fas and FasL expression, both at the level of protein and of mRNA, was increased, whereas Bcl-2 expression was decreased both at the level of protein and of mRNA. However, no difference in Bcl-XL expression was observed between the patient and an age-matched control. A significant proportion of both CD4+ and CD8+ T cells from the patients underwent spontaneous apoptosis, whereas almost no spontaneous apoptosis was observed in the age-matched control. These data suggest that spontaneous apoptosis in T lymphocytes, at least in part, may be responsible for T cell deficiency in DiGeorge anomaly.