Daniel P. Stites

Seropositivity for HIV and the development of AIDS or AIDS related condition: three year follow up of the San Francisco General Hospital cohort

The three year actuarial progression rate to the acquired immune deficiency syndrome (AIDS) in a cohort of men in San Francisco who were seropositive for the human immuno-deficiency virus (HIV) was 22%. An additional 26 (19%) developed AIDS related conditions. β2 Microglobulin concentration, packed cell volume, HIV p24 antigenaemia, and the proportion and number of T4 lymphocytes each independently predicted progression to AIDS. β2 Microglobulin was the most powerful predictor. The 111 subjects tested who were normal by all predictors (40%) had a three year progression rate of 7%, and the 68 subjects who were abnormal by two or more predictors (24%) had a progression rate of 57%. Two thirds of all men who progressed to AIDS were in the last group. The median T4 lymphocyte count in subjects who did not progress to AIDS fell from 626 × 106 to 327 × 106/1. HIV p24 antigenaemia developed in 7% of the subjects per year. The proportion who were abnormal by two or more predictive variables rose to 41%. At three years an estimated two thirds of the seropositive subjects showed clinical AIDS, an AIDS related condition, or laboratory results that were highly predictive of AIDS. It is concluded from the observed rates and the distribution of predictive variables at three years that half of the men who were seropositive for HIV will develop AIDS by six years after the start of the study, and three quarters will develop AIDS or an AIDS related condition.

AIDS-associated retroviruses (ARV) can productively infect other cells besides human T helper cells

We have examined the host range of AIDS-associated retroviruses (ARV) that are known to infect human T cells of the helper subset. We have observed that the virus cannot infect fibroblast and epithelial cell lines of many different animal species. It is infectious and replicates efficiently in peripheral mononuclear cells (PMC) of chimpanzee and at low levels in baboon and rhesus monkey PMC. Most importantly, it has been found to replicate in established lines of human B cells, monocytes, and promyelocytes. This ability to infect these other cell types appears to be associated, in most cases, with the presence of the Leu 3 T helper cell antigen on the cell surface. Other mechanisms for virus infection, however, may be involved. The results suggest that ARV will be found in other cells of AIDS patients, besides T cells, and that these cells could be the reservoir for continual virus spread in the host. Variations in the replicative ability of ARV isolates in human cells have also been noted; they could reflect potentially important pathogenic differences among these human retroviruses.

Cytotoxic T Lymphocyte Responses to E6 and E7 Proteins of Human Papillomavirus Type 16: Relationship to Cervical Intraepithelial Neoplasia

Cytotoxic T lymphocyte (CTL) responses to the human papillomavirus (HPV) type 16 E6 and E7 proteins were measured in 20 women with known HPV and cervical disease status. CTL assays were performed after stimulation with E6 or E7 fusion proteins using autologous B lymphoblastoid cells infected with vaccinia viruses expressing E6 or E7. CTL responses to E6 and E7 were detected in 6 (75%) of 8 and 5 (56%) of 9 HPV-16-positive women without cervical intraepithelial neoplasia (CIN), respectively. Responses to E6 or E7 were each detected in only 2 (29%) of 7 HPV-16-positive women with CIN. Responses to both antigens were found in 63% of women without CIN and 14% of those with CIN. CTL responses to E6 or E7 are more commonly detectable in HPV-16-positive women without CIN than in HPV-16-positive women with CIN, suggesting that CTL response may play a role in disease protection.

Persistence of Human Papillomavirus Type 16 Infection Is Associated with Lack of Cytotoxic T Lymphocyte Response to the E6 Antigens

Our cross-sectional study suggested that cytotoxic T lymphocyte (CTL) responses have a protective effect in squamous intraepithelial lesion (SIL) development. More CTL responses in women with human papillomavirus type 16 (HPV 16) infection without SILs than with SILs were detected. In the current longitudinal study, the role of CTL in clearing HPV 16 infection in women without SILs was investigated. Women with HPV 16 infection (n=51) were enrolled, along with HPV 16-negative control women (n=3). Twenty-two (55%) of 40 women who cleared HPV 16 infection had an E6 CTL response at least once, compared with none of 9 women who had HPV 16 persistence (P=.003). Such a difference was not demonstrated for E7; 25 (63%) of 40 women who cleared HPV 16 infection responded, versus 5 (56%) of 9 women with persistence (P=.720). It appears that lack of response to E6 is important in the persistence of HPV 16 infection.

Infection with Human Immunodeficiency Virus Type 1 (HIV-1) among Recipients of Antibody-Positive Blood Donations

OBJECTIVE To assess the incidence of human immunodeficiency virus type 1(HIV-1) transmission by antibody (anti-HIV-1)-positive blood components, and to determine the immunologic and clinical course in HIV-1-infected recipients. DESIGN AND SUBJECTS We retrospectively tested approximately 200,000 donor blood component specimens stored in late 1984 and 1985 for anti-HIV-1, and we contacted recipients of positive specimens to determine their serologic status. They were compared with both recipients of HIV-1-negative transfusions and healthy (untransfused) controls. Subjects were seen at 3- to 6-month intervals for up to 4 years for clinical and immunologic evaluations. MEASUREMENTS AND MAIN RESULTS Of 133 recipients, 9 had other possible exposures. Excluding these cases, 111 of 124 (89.5%) were anti-HIV-1-positive (95% CI, 84.1% to 94.5%). The recipients sex, age, underlying condition, and type of component did not influence infection rates. The cumulative risk for developing the acquired immunodeficiency syndrome (AIDS) within 38 months after transfusion was 13% (CI, 7.5% to 21.6%). At 36 +/- 3 months after the index transfusion, seropositive recipients had lower counts of CD2+CDw26+, CD4+, CD4+CD29+, and CD4+CD45RA+subsets and more CD8+I2+ lymphocytes than did recipients of anti-HIV-1-negative transfusions. The CD4+ and CD2+CDw26+subsets changed the most rapidly. The absolute CD8+ count remained normal. CONCLUSIONS Transfusion of anti-HIV-1-positive blood infected 90% of recipients. The rate of progression to AIDS within the first 38 months after infection was similar to that reported for homosexual men and hemophiliacs. Although most lymphocyte subset counts changed over time, CD8+ counts were constant.

The Wiskott-Aldrich Syndrome: RESULTS OF TRANSFER FACTOR THERAPY

12 patients with Wiskott-Aldrich syndrome were treated with therapeutic doses of transfer factor in an attempt to induce cellular immunity. Clinical improvement was noted after transfer factor therapy in 7 of the 12 patients treated. Because this disease has a variable course and temporary spontaneous improvement can occur, the observed improvement cannot necessarily be attributed to the transfer factor. However, in two patients repeated remissions consistently followed transfer factor administration on repeated occasions. This included freedom from infections, regression of splenomegaly, and clearing of eczema. An unexpected finding was a decrease in bleeding in 3 of the 10 patients who had bleeding. Conversion of skin reactivity was obtained in all seven patients who clinically seemed to respond to transfer factor. In vitro studies performed after the administration of transfer factor demonstrated that the lymphocytes of the patients now produced migration inhibitory factor in response to appropriate test antigens, but did not undergo increased radioactive thymidine incorporation in response to the same antigens. A defect in the monocyte IgG receptors has been found in certain patients with the disease, and the current study shows that all patients with defective monocyte IgG receptors responded to transfer factor, whereas only one patient with normal receptors showed any response. This test may thus prove to be useful in predicting the results of transfer factor therapy in patients with Wiskott-Aldrich syndrome, although evaluation of a larger series of patients will be necessary to confirm this point. We conclude that cellular immunity can be induced, that there appears to be clinical benefit in certain patients with Wiskott-Aldrich syndrome by the use of transfer factor, and that this mode of therapy warrents trial in these patients and others with defects of cellular immunity.

Bacillary Angiomatosis and Bacillary Splenitis in Immunocompetent Adults

Bacillary angiomatosis and parenchymal bacillary peliosis are recently described vascular disorders associated with infection by Rochalimaea henselae and Rochalimaea quintana, which occur in patients with either human immunodeficiency virus (HIV) infection or drug-induced immune suppression [1-5]. In addition, R. henselae and R. quintana (also the agent of trench fever) are both members of the family Rickettsiaceae [1, 4, 5], and infections due to Rochalimaea species have been associated with exposure both to cats [2] and to arthropod vectors [1, 5]. We describe five patients with cutaneous bacillary angiomatosis or bacillary splenitis without evidence of HIV infection who were determined to be immunocompetent after immunologic evaluation. In three patients with both cat and cat flea exposures, infection by R. henselae was confirmed by amplification and sequencing of 16S rDNA from an infected tissue specimen. Methods Four patients with characteristic vascular lesions of cutaneous bacillary angiomatosis [1, 3] were examined. Patient 2, who lacked vascular lesions, had a 2-week history of left-sided abdominal pain, shortness of breath, low-grade fever, nausea, diarrhea, and weight loss of 3.5 kg. Results of laboratory studies included hematocrit, 0.21 (2 months before it had been 0.34); lactate dehydrogenase, 1170 U/L; total bilirubin, 53 mol/L (3.1 mg/dL); conjugated bilirubin, 24 mol/L (1.4 mg/dL); and mildly elevated hepatic transaminases and alkaline phosphatase. A computed axial tomography scan of the abdomen showed a normal liver and hypersplenism with a 4-cm2 area of focal low attenuation. The patient underwent emergency splenectomy for impending rupture. The 1100-g spleen revealed a 4.5-cm3 mottled area consistent with infarction and two 0.6-cm3 tan nodules beneath the capsular surface. Results of routine bacterial cultures were negative. In June 1991, all five patients had blood drawn for HIV culture, serologic analysis, and polymerase chain reaction studies using techniques described previously [6, 7]. In August 1991, all patients had blood drawn for immunologic evaluation, including quantitative immunoglobulins, complement, lymphocyte subset percentages, neutrophil oxidative burst [8, 9], T-lymphocyte activation studies to phytohemagglutinin, and B-lymphocyte activation studies to pokeweed mitogen [10, 11]. After their blood was drawn, patients had skin test antigens to purified protein derivative, mumps, Trichophyton, and Candida albicans placed and read at 48 hours. The diagnosis of cutaneous bacillary angiomatosis was established using defined histopathologic criteria [3]. Bacterial DNA present in the infected tissue specimen was extracted from either frozen skin biopsy tissue (Patient 4) or from sections of formalin-fixed, paraffin-embedded biopsy specimens [1, 12]. Insufficient tissue was available from Patients 1 and 3. Extracted DNA was amplified by polymerase chain reaction using primers p24E and p12B [1, 12]. Control tissues were simultaneously extracted and amplified [1]. Amplified 16S rDNA products from Patients 2, 4, and 5 were sequenced as described previously [1]. Results Only Patient 2 had a well-documented antecedent chronic illnesshereditary spherocytosis and noninsulin-dependent diabetes mellitusand no patient was receiving immunosuppressive drugs (Table 1). Idiopathic hemochromatosis was diagnosed concomitantly with bacillary angiomatosis in Patient 3. All patients responded to oral antimicrobial therapy of 4 to 6 weeks duration. Histologic examination of skin biopsy specimens from Patients 1, 3, 4, and 5 were diagnostic of bacillary angiomatosis; splenic tissue from Patient 2 showed necrotizing splenitis with fibromyxoid changes, degenerating neutrophils, and mononuclear cells in the absence of both vascular proliferation and granuloma formation. Specimens from all patients showed many bacilli on both Warthin-Starry staining and electron microscopic examination. Table 1. Characteristics of Immunocompetent Patients with Bacillary Angiomatosis and Bacillary Splenitis Amplification of the DNA extracted from infected tissue from Patients 2, 4, and 5 produced a 16S rDNA fragment of approximately 300 base pairs. The amplified DNA fragment from tissue of Patients 2 and 4 is shown in Figure 1. The sequence of this 16S rDNA fragment from Patients 2, 4, and 5 was identical to that of R. henselae [4, 12]. Figure 1. Amplification of Rochalimaea DNA. Rochalimaea henselae R. henselae Discussion We evaluated four patients with cutaneous bacillary angiomatosis and one with bacillary splenitis and found no evidence of HIV infection using a combination of sensitive HIV antibody and antigen assays, as well as viral culture and polymerase chain reaction techniques. In addition, both cellular and humoral immunity were evaluated and no abnormality was found. Because host defense mechanisms against Rochalimaea species are not well understood, defects may have been undetected by our methods. Two patients had underlying illnesses that may be associated with altered immune function, but no consistent immune defect has been associated with these conditions [13-15]. The histopathologic findings were diagnostic for bacillary angiomatosis in all four patients with cutaneous disease; tissue from Patient 2 showed necrotizing splenitis with characteristic bacillary organisms [3, 12]. Amplification and sequencing of rDNA from tissue of Patients 2, 4, and 5 confirmed that the infecting organism was R. henselae. Although we cannot speciate the bacilli seen in abundance with the Warthin-Starry stains of Patients 1 and 3, the histopathologic changes met all criteria for the diagnosis of cutaneous bacillary angiomatosis [3], a disease associated with R. henselae and R. quintana [1]. Bacillary splenitis in the absence of peliosis appears to be another manifestation of R. henselae infection. A clinical spectrum of R. henselae infection may exist, beginning with fever and bacteremia, progressing to bacillary splenitis and finally to bacillary peliosis. Differences in host immune function also may play a role in disease progression. The diagnosis of cutaneous bacillary angiomatosis and bacillary splenitis should be pursued in the immunocompetent patient when clinical or histopathologic features are suggestive. On the basis of these five patients, we recommend treatment with erythromycin or doxycycline for at least 6 weeks when the diagnosis is confirmed.

Suppressive effect of seminal plasma on lymphocyte activation.

ALTHOUGH spermatozoa bear histocompatibility antigens (H-2 in mice1,2 and HL-A in man3,4) accelerated (immune) skin graft rejection is not known to occur in females previously multiply inseminated by a graft donor. The absence of detectable transplantation immunity in inseminated females correlates with the generally low immunogenicity of spermatozoa given by other routes. The decreased antigenicity of spermatozoa is not explained by a privileged immune status of the female reproductive tract as the vaginal route is adequate for immunisation against a variety of antigens5, especially if the tract is wounded6, and antibodies to spermatozoa decrease fertility in some situations7. Thus, it is probable that mechanisms have evolved to maintain a low immunogenicity of spermatozoa. What seems to be an exception to the low immunogenicity of spermatozoa—that antibody to a tissue-specific sperm antigen occurs naturally without deliberate immunisation8,9 and is readily elicited in a variety of species10—may represent a protective mechanism. Many substances present in seminal plasma may exert a suppressive effect by coating sperm membrane antigens or inducing immunosuppression by other means.

Ontogeny of cellular immunity in the human fetus: development of responses to phytohemagglutinin and to allogeneic cells.

Abstract Human fetal lymphoid cells from thymus, spleen, blood, liver, and bone marrow of 22 fetuses (5–19 weeks of fetal age) were studied for their ability to respond to phytohemagglutinin and to adult allogeneic lymphocytes by the mixed lymphocyte reaction. The earliest detectable response was that by hepatic cells in the mixed lymphocyte reaction at 7.5 weeks of fetal age. Phytohemagglutinin reactivity was initially seen in the thymus at 10 weeks, in blood at 14.5 weeks, and in spleen at 13 weeks. Mixed lymphocyte reaction reactivity was first detected in the thymus at 12.5 weeks; it appeared somewhat later in peripheral organs. Few significant responses to phytohemagglutinin were detected in bone marrow or hepatic cells, and virtually no response to allogeneic cells was found in bone marrow. All lymphoid cells studied showed stimulatory ability in the mixed lymphocyte reaction. However, spleen, blood, and marrow cells produced higher stimulation of allogeneic cells than did thymic or hepatic cells.

Flow cytometric analysis of lymphocyte phenotypes in AIDS using monoclonal antibodies and simultaneous dual immunofluorescence

Simultaneous dual immunofluorescence and flow cytometry was used to study sixteen lymphocyte phenotypes in 209 men including: healthy homosexuals, lymphadenopathy patients (LAN), and AIDS patients. Significant differences between the distribution of lymphocytes in healthy homosexuals and healthy heterosexuals were decreased percentages of helper/inducer T cells (Leu 3), increased cytotoxic/suppressor T cells (Leu 2), and consequently a decreased Leu 3/Leu 2 ratio. The increased Leu 2 cells were identified as functionally cytotoxic subset Leu 2+ 15- phenotype rather than suppressor cells which are Leu 15+. Leu 2 and Leu 3 bearing cells exhibited an excess of membrane-bound immunoglobulins which were easily elutable at 37 degrees C. An increased percentage of an HLA-DR framework determinant bearing T cells were also detected. Within the NK cell family, Leu 7 cells were moderately increased and the functionally unidentified Leu 2+ 7+ population was strikingly elevated. LAN or AIDS patients were compared to healthy homosexual controls. Lower percentages of Leu 3 cells and higher percentages of Leu 2 cells were evident in LAN patients. These subsets were similar in LAN and AIDS patients. The increase in Leu 2+ cells was due to the Leu 2+ 15- cytotoxic subset. Fewer T cells had immunoglobulin in LAN and AIDS. A definite increase in Leu 2+ DR+ cells but not Leu 3+ DR+ cells occurred in AIDS compared to LAN or healthy controls. NK cell changes already present in healthy homosexuals persisted in LAN and AIDS patients. No differences in the distribution of B cells was detected in any intergroup comparisons. Changes in monocytes or pan-T cells were relatively insensitive measures of immunologic alterations among any of the groups. These results indicate many of the changes in lymphocyte subsets seen in AIDS and LAN subjects are already present in a carefully screened population of healthy homosexuals in San Francisco. Many of the changes in Leu 2 and NK family of cells suggest a possible adaptive response to viral or neoplastic challenge. Whether these interesting phenotypic alterations relate to functional changes in response to such challenge of the identified subsets waits further investigation.