Human saliva is known to decrease human immunodeficiency virus type 1 (HIV-1) infectivity in vitro. The purpose of this study was to confirm these findings and to explore the mechanism of action of saliva. Whole saliva from seronegative donors was incubated with HIV-1_IIIB chronically infected MOLT 4 cells (MOLT 4/HIV-1_IIIB cells) or cell-free HIV-1_{IIIB or KMT} strains. We monitored viral infectivity by using MAGI/CCR5 cells. Whole saliva with Na levels less than 20mEq/l rapidly damaged MOLT 4/HIV-1_IIIB cells, thereby HIV infection to MAGI/CCR5 cells by MOLT 4/HIV-1_IIIB cells was nearly abolished. On the contrary, in the cace of whole saliva with Na levels more than 23mEq/l which damaged few cells, cell-to-cell transmission of HIV-1_IIIB was prevented by more than 50%. The infectivity of cell-free HIV-1_IIIB to MAGI/CCR5 cells was abolished after incubating and filtering the HIV with whole saliva. Depletion of secretory leukocyte protease inhibitor (SLPI) from whole saliva resulted in a 1128% decrease in the anti-HIV-1_KMT activity of saliva. Preincubation of host cells with whole saliva led to an enhancement of the HIV infection rather than inhibition. Whole saliva had no effect on the expression level of the cellular receptors (CD4, CXCR4 and CCR5). These results suggest that the inhibitory effect of whole saliva on HIV-1 infectivity is directly linked to the virus itself rather than on the host cell. Moreover, the physical entrapment of cell-free HIV-1 by whole saliva seems to have major salivaly defence mechanisms against HIV-1 infection through the oral cavity.

View full abstract

A 64-year-old female was admitted in May 1997, because of salivary gland swelling. Histology of the right parotid gland revealed malignant lymphoma, diffuse medium-sized B-cell type, and she was treated with local radiotherapy and chemotherapy. She was rehospitalized in April 1998, because of recurrence of lymphoma in the stomach and the sigmoid colon. She had splenomegaly and lymphadenopathy (neck and inguinal). Laboratory findings revealed marked elevation of rheumatoid factor and RNA of hepatitis C virus. A diagnosis of Sjögren's syndrome was made by dryness and the histological findings of labial biopsy. Marginal zone B-cell lymphoma mainly consisted of centrocyte-like cells and lymphoepithelial lesions, and CD 20 and IgM-κ were positive with immunohistochemical staining. Lymphoma involved the gut and spleen. We discuss the correlation of malignant lymphoma with Sjögren's syndrome and HCV infection.

View full abstract

A 63-year-old man, with a 13-year history of asymptomatic proteinuria, was diagnosed with left atrial myxoma at the onset of heart failure. After resection of the tumor by hypothermal surgery, the patient developed fever, renal failure and skin rash. The diagnosis was type II mixed cryoglobulinemia accompanied by an IgMλ clone with high titers of rheumatoid factor activity and polyclonal IgG. Treatment with high doses of steroids and plasmapheresis was ineffective, and the patient died of colon necrosis due to thrombotic occlusion in the supra-mesenteric arteries. Although the patient had suffered from sporadic Raynaud's phenomenon and purpura of the lower extremities from the age of 60 years, cryoglobulinemia was not suspected before surgery because of the atrial myxoma. Thus, we suggest that it is important to perform laboratory tests for cryoproteins before hypothermal surgery.

View full abstract