Increased frequency of HLA-DR11 in pediatric human immunodeficiency virus-associated parotid gland enlargement.

We sought to determine whether an increased frequency of the HLA-DR11 (formerly DR5) phenotype is found in human immunodeficiency virus (HIV)-infected children with parotid gland enlargement. In HIV-infected adults, parotid gland enlargement may be part of the diffuse infiltrative CD8 lymphocytosis syndrome. An increased frequency of expression of HLA-DR11 has been described in association with diffuse infiltrative CD8 lymphocytosis syndrome. We conducted a case-control study with 26 HIV-infected children, 13 of whom had parotid gland enlargement and 13 of whom did not but who were matched for age, race, and sex with those with parotid gland enlargement. Clinical and laboratory parameters (including HLA-DR11 phenotype) were compared between the two groups. HIV-positive children with parotid gland enlargement showed an increased frequency of HLA-DR11, similar to their adult counterparts with diffuse infiltrative CD8 lymphocytosis syndrome. The HLA-DR11 phenotype may be associated with the development of parotid gland enlargement in HIV-infected children and may be a marker for a more benign outcome of HIV infection.

Human immunodeficiency virus infection and multilocular thymic cysts.

PURPOSE: Pathologic changes of the thymus, often seen in children with the human immunodeficiency virus (HIV), reflect direct invasion by the virus, followed by involution of the gland. A previously unknown form of thymic response to HIV infection, that of a multilocular thymic cyst, is reported. MATERIALS AND METHODS: Findings were examined in three HIV-positive patients, two children and one adult first seen with large thymic masses. RESULTS: All three had large, septate low-attenuation areas at computed tomography consistent with multilocular thymic cysts. The cystic nature of the lesions was confirmed with magnetic resonance imaging in two. Histopathologic examination, performed in two instances, helped establish the diagnosis. All patients remained in clinically stable condition. They all had parotid gland enlargement and lymphocytic interstitial pneumonia. CONCLUSION: Multilocular thymic cysts are probably another manifestation of the diffuse infiltrative lymphocytosis syndrome, usually associated with a milder course of acquired immunodeficiency syndrome.

Flow cytometric analysis of natural killer cell function as a clinical assay.

The 51Cr release assay has been the method of choice in analyzing natural killer cell (NK) function. Previous FCM cytotoxicity assays of NK activity have had numerous disadvantages that discouraged clinicians from attempting to evaluate NK function by flow cytometry. We demonstrate the effectiveness of using PKH-26, a stable membrane dye, to label the K562 target cells and propidium iodide intercalation into killed target cell DNA to determine the percentage of target cells killed by effector NK cells from the peripheral blood or bone marrow. This method compares favorably with the 51Cr release assay and is quicker and easier to perform. The percentage of cytotoxicity of NK cells (CD3- CD56+ and/or CD16+) from 10 normal subjects and 10 HIV-infected children are reported to demonstrate the feasibility of studying NK function in clinical populations by FCM. The potentiation of cytolysis by alpha-interferon and interleukin 2 in vitro was also compared between these two study groups. In addition, a patient whose leukemic blasts expressed CD56+ was also studied for NK activity using this flow cytometric assay. The benefits of using this flow cytometric approach to clinically assess NK function are discussed.

Rheumatologic manifestations of pediatric human immunodeficiency virus infection.

OBJECTIVE: Multiple rheumatologic signs and symptoms have been described in adult human immunodeficiency virus (HIV) infection. Our goals were to determine the incidence and characteristics of rheumatologic manifestations in HIV infected children, and to examine their relationship to laboratory evidence of autoimmunity. METHODS: Forty HIV infected children were studied by means of a questionnaire, history, examination, and serologic testing including determination of concentrations of immunoglobulin, C3, C4, and of presence of antinuclear antibodies (ANA), rheumatoid factor (RF), and circulating immune complexes (CIC). RESULTS: Rheumatologic manifestations included arthralgia (15%), myalgia (8%), erythema multiforme (3%), and parotitis (20%). Hypergammaglobulinemia (98%), hypocomplementemia (25%), RF (10%), ANA (3%), and CIC (82% of patients studied) were also found. Patients with or without rheumatologic manifestations did not differ significantly in any laboratory variable measured. CONCLUSIONS: In contrast to HIV infected adults, HIV infected children, do not display serious rheumatologic manifestations. Mild rheumatologic symptoms are common, but there is little evidence that these are immune mediated. Parotid enlargement occurs and must be differentiated from Sjögren's syndrome. Differences between rheumatologic manifestations of HIV infection in children and adults may reflect host factors such as the immaturity of the pediatric immune system, or environmental factors such as modes of acquisition of HIV, duration of HIV infection, or exposure to other sexually transmitted organisms.

Panniculitis and fever in children.

We describe three children with panniculitis and associated systemic manifestations including fever. Histopathologic features, such as the presence of lobular or septal inflammation, presence of vasculitis, character of the cellular infiltrate, and presence of erythrophagocytosis, were useful in classifying this group of panniculitides. In one patient with subcutaneous polyarteritis nodosa, corticosteroid therapy was effective; in two other patients with histiocytic cytophagic panniculitis, there were poor responses to steroids, intravenously administered immune globulin, dapsone, or antimalarial drugs; cyclosporine was very effective and appeared to be the drug of choice.

Dysfunction of natural killer cells in human immunodeficiency virus-infected children with or without Pneumocystis carinii pneumonia.

The development of Pneumocystis carinii pneumonia (PCP) in human immunodeficiency virus (HIV)-infected children with normal T-cell numbers is contrary to previous experience with HIV-infected adults, in whom low CD4+ T-cell numbers predict susceptibility to PCP. To determine whether PCP in HIV-infected children reflects a qualitative T-cell or other immune defect, we studied four HIV-infected children who also had PCP and 10 others without PCP for T-cell and natural killer (NK) cell function. Most of the HIV-infected children had normal T-cell numbers for age, and all had CD4+ T-cell numbers greater than those predictive of PCP in HIV-infected adults. All HIV-infected children had normal T-cell function in vitro. The HIV-infected children as a whole had deficient NK cell cytolysis. We obtained a significant interactive effect of age by health status for NK cell function between patients and age-matched control subjects. All HIV-infected children with defective NK cell function failed to enhance their NK cell cytolysis when their mononuclear cells were stimulated with recombinant interferon alfa (r-IFN-alpha). This NK cell defect in HIV-infected children may facilitate the development of secondary infection.

Cytomegalovirus and Pneumocystis carinii pneumonia in children with acquired immunodeficiency syndrome.

To ascertain the effect of cytomegalovirus (CMV) infection on the course of Pneumocystis carinii pneumonia (PCP) in children with acquired immunodeficiency syndrome (AIDS), we reviewed the charts of all children with AIDS who also had a lung biopsy specimen or a bronchoalveolar lavage specimen cultured for CMV at the time PCP was diagnosed. The data indicate that children with AIDS and PCP whose cultures are positive for CMV do not have a poorer prognosis during a first episode of PCP compared with children whose cultures are negative for CMV.