Clinical range of T cell lymphopenias among 22q11.2DS patients
| Thymic hypoplasia (60–70%) . | More severe thymic hypoplasia . | Congenital athymia (<1%) . | Normal thymus (30–35%) . |
|---|---|---|---|
| Reduced CD3+ T cells (<1,500 cells/µl) | Low CD3+ T cells (>50 and <400 cells/µl) | Very low CD3+ T cells (<50 cells/µl) | CD3+ T cells >1,500 cells/µl |
| Reduced numbers of naïve T cells and expanded memory T cells | Low naïve T cells (>50 cells/µl; >5% and <50% total T cells) | Low naïve T cells (<50 cells/µl; <5% total T cells) | Higer naïve to memory T cell ratios (infants) |
| TREC levels are not flagged as abnormal | Undetectable or very low TRECsa | Undetectable or very low TRECsa | Normal TRECs |
| Elevated T follicular helper cells | | Possible maternal engraftment | |
| Treatment strategies | |||
| Monitor and possible prophylactics | Monitor and possible prophylactics | Thymic implant (transplant) | Not applicable |
| Thymic hypoplasia (60–70%) . | More severe thymic hypoplasia . | Congenital athymia (<1%) . | Normal thymus (30–35%) . |
|---|---|---|---|
| Reduced CD3+ T cells (<1,500 cells/µl) | Low CD3+ T cells (>50 and <400 cells/µl) | Very low CD3+ T cells (<50 cells/µl) | CD3+ T cells >1,500 cells/µl |
| Reduced numbers of naïve T cells and expanded memory T cells | Low naïve T cells (>50 cells/µl; >5% and <50% total T cells) | Low naïve T cells (<50 cells/µl; <5% total T cells) | Higer naïve to memory T cell ratios (infants) |
| TREC levels are not flagged as abnormal | Undetectable or very low TRECsa | Undetectable or very low TRECsa | Normal TRECs |
| Elevated T follicular helper cells | | Possible maternal engraftment | |
| Treatment strategies | |||
| Monitor and possible prophylactics | Monitor and possible prophylactics | Thymic implant (transplant) | Not applicable |
Flagged by newborn screening and may vary between testing centers.