DILS (diffuse infiltrative lymphocytosis syndrome) in a patient with HIV infection
DILS is diagnosed by (1) HIV-positive infection, (2) presence of bilateral, painless salivary gland enlargement or xerostomia persisting >6 months, and (3) histologic confirmation of salivary or lacrimal gland lymphocytic infiltration with predominantly CD8+, CD29 T cells in the absence of granulomatous or neoplastic enlargement, or confirmatory 67 Ga scintigraphy. There is a much higher prevalence of DILS in Africa than in the United States. The onset of symptoms usually presents at a mean period of 3 years before the diagnosis of HIV infection. It is characterized by xerophthalmia, xerostomia, parotid gland enlargement, parotid cysts, persistent circulating CD8+ T-cell lymphocytosis, and diffuse visceral lymphocytic infiltration. Pulmonary involvement as a result of lymphocytic interstitial pneumonitis is the most serious complication of DILS and has decreased significantly with ART. Cranial nerve palsies (VII due to parotid compression), aseptic meningitis, and symmetric, peripheral motor neuropathy may occur. Lymphocytic hepatitis, interstitial nephritis, type IV renal tubular acidosis, PM, and lymphoma have also been observed. Low to moderate dose of corticosteroids for glandular enlargement and sicca symptoms is beneficial. Topical treatment is usually satisfactory, but pilocarpine (5–10 mg thrice a day) may be necessary for severe sicca symptoms. High-dose corticosteroids and ART are used for severe extraglandular involvement.
Comparison of Sjögren’s Syndrome and DILS
| Sjögren’s | DILS | |
|---|---|---|
| Parotid swelling | Uncommon | Common |
| Sicca symptoms | Common | Common |
| Extraglandular manifestations | Uncommon | Common |
| Infiltrative lymphocytic phenotype | CD4+ T cells | CD8+ T cells |
| Autoantibodies (RF, ANA, anti-SS-A/SS-B) | Common | Rare |
| HLA association | DRB1∗0301 | DRB1∗1102, 1301, 1302 |
| Corticosteroids for glandular symptoms | Rarely helpful | Beneficial |
