Clinical and Morphological Analysis of Lymphoid Interstitial Pneumonia (LIP) Variants in Adult HIV Patients: A Retrospective Study of 25 Cases
R Hughes, J Park, N Edgerton, N Vogenthaler, MB Mosunjac, MI Mosunjac. Emory University, Grady Memorial Hospital, Atlanta, GA
Background: The diagnosis of LIP encompasses both clinical and pathological patterns of pulmonary disease characterized by a diffuse interstitial lymphoid infiltrate. Its association with HIV has been previously demonstrated, and recently the incidence of HIV-associated LIP has been on the rise. This trend has been primarily observed in children with AIDS. However in the adult HIV population, the incidence of LIP remains stable. Here, we describe the clinical, laboratory and morphological features of the largest series of HIV-associated LIP in adult patients.
Design: Twenty-five lung biopsies with a diagnosis of LIP were identified between 1992 and 2008. Pathology reports, H&E slides and available fungal and immunohistochemical stains (GMS, CD3, CD20) were reviewed. Clinical and laboratory data data was obtained from the patients' charts.
Results: Of 25 patients, there were 4 females and 21 males with an average age of 38.4 years. Sixty-four percent of the patients lacked documented risk factors for HIV, while thirty-four percent of patients had a history of drug abuse. The average duration of HIV infection at the time of LIP diagnosis was 79 months. Morphologically, two LIP patterns were identified; 13 cases contained nodular lymphoid infiltrates, and 12 exhibited a diffuse interstitial pattern. Of the four female patients, three showed the diffuse interstitial pattern. Frequently, the nodular pattern was clinically mistaken as miliary TB or metastatic tumor (61.5%). CD8 lymphocytosis was observed in more than 75% of cases with an average CD8 count of 1541 cells/mm3. The average CD4 count was 282 cells/mm3 with an average viral load of 242,270 copies/mL. There was no statistical significance between morphological patterns of LIP and CD4/CD8 count, duration of HIV, or risk factors.
Conclusions: Here we present the largest series of LIP in adult HIV patients. All of the patients showed a long duration of HIV infection with significant CD8 lymphocytosis. The most prominent risk factor identified was drug abuse. Of the four female patients, three showed the diffuse interstitial pattern. There was no significant distinction in laboratory or clinical findings between the two morphological LIP patterns. The nodular pattern was clinically more often diagnosed as miliary TB or metastatic tumor nodules.
Monday, March 9, 2009 1:00 PM
Poster Session II # 186, Monday Afternoon