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The potential for transmission of human immunodeficiency virus (HIV) type 1 has created serious concern for the continued clinical use of bone and soft-tissue allografts. Tissue banks have employed 1.5–2.5 Mrad for sterilization of bone and tendon allografts, which, according to the current literature, approaches the level at which the tissue quality is adversely affected for implantation. Our working hypothesis was that gamma irradiation at increasing doses can proportionately inactivate HIV type 1. The objective of this study was to inactivate HIV type 1 by irradiation, as determined by its capacity to infect human T-lymphocytes and established cell lines in vitro. The replicative competence of HIV type 1 was also assessed by the presence of reverse transcriptase activity, enzyme-linked immunoadsorbent assay (ELISA), immunofluorescence assays for p24 viral core antigen, and the formation of syncytia induced by HIV type 1 in the cultures inoculated with irradiated virus. The results demonstrated the presence of active viral replication in previously noninfected cells in the supernatant samples that were exposed to as much as 5.0 Mrad. The data for the 10-Mrad sample were indeterminate due to cellular damage. These data suggest that gamma irradiation (1.5–2.5 Mrad) does not constitute a virucidal dose for HIV type 1. Current technologies for screening have greatly improved, and the surgeon should rely on tissue bank screening procedures and other methods of preparation rather than sterilization by gamma radiation techniques in choosing allograft material.

Summary: Pneumocystis carinii was propagated in vitro with primary embryonic chick epithelial lung (CEL) cells. Viability and growth of the organism were demonstrated by direct observation of the reproductive cycle in the Sykes-Moore chamber, serial passage with an increase in the number of mature cyst forms, the cytopathic effect of the organism on cell culture, and inhibition of growth of the organism by specific antiserum and pentamidine isethionate. Attempts to culture P. carinii indefinitely were not successful. However, cyst forms derived from murine and human sources increased 100-fold and 10-fold, respectively, during CEL cell culture passages. Serial passage of trophozoites alone resulted in the development of typical CPE and a maximum number of 2.8 103 cyst forms. Autoradiographic methods demonstrated active DNA, RNA, and protein synthesis within the cyst and suggest that metabolic interaction between the host cells and the organisms occurred. The nature of the attachment of P. carinii to the host CEL cell was clearly discernible by scanning electron microscopy (SEM). In the reproductive cycle a vegetative cell (designated “trophozoite”) attached by tubular expansions to the host CEL cell, probably for the transport of essential nutrients, and then detached without entering the cell. Sporozoites developed within the detached young cyst, reaching a maximum number of eight within the mature cyst. Excystment occurred through single or multiple sites in the cyst wall, after which the released trophozoite attached to a new host cell. Speculation: The in vitro propagation of P. carinii provides a basis for further studies to characterize the biologic and biochemical features of this organism and a source of antigen for the development of serologie tests for specific antibody by which the epidemiology and spectrum of clinical disease can be delineated more clearly.

The present study was conducted to determine the prevalence and significance of Pneumocystis carinii antigenemia in patients with acquired immunodeficiency syndrome (AIDS) and clinically or invasively diagnosed P. carinii pneumonitis. Single serum specimens from 20 AIDS patients invasively examined for P. carinii organisms and 106 AIDS patients with a clinical diagnosis only of P. carinii pneumonitis were blindly tested for P. carinii antigenemia by a counterimmunoelectrophoresis assay. In the 20 specimen-documented cases, the antigen test demonstrated a sensitivity of 75% and a specificity of 90%. The positive predictive value of the test was 90%, while the negative predictive value was 70%. In AIDS patients with specimen-documented P. carinii pneumonitis, the prevalence of P. carinii antigenemia coincided almost exactly with the prevalence of positive invasively obtained specimens (60 and 59%, respectively). In patients with a clinical diagnosis only of P. carinii pneumonitis, half as many (30%) were found to exhibit antigenemia. Sequential P. carinii antigen titers determined by a new latex agglutination technique on three AIDS patients with specimen-documented P. carinii pneumonitis demonstrated the influence of specific therapy upon P. carinii antigenemia and its potential prognostic application.

A new latex particle agglutination test for direct detection of Haemophilus influenzae type b polyribose phosphate antigen in serum, cerebrospinal fluid, or urine was evaluated from studies at four clinical centers. Although use of a serum buffer significantly reduced inconclusive agglutination of the latex particles, the retesting of serum samples, after heat inactivation and dilution, resolved all serum samples, with one exception, as reactive or nonreactive for the presence of the polyribose phosphate antigen. A clinical accuracy of 100% was obtained for the latex particle agglutination method in respect to its capability for detection of polyribose phosphate antigen in all patients with confirmed infection by H. influenzae type b.

Pneumocystiscarinii infections have been detected both serologically and histologically in untreated, germ-free and conventional rats killed immediately upon arrival from two commercial sources. Pneumocystis antigenemia was detected by counterimmunoelectrophoresis (CIE) and antibody was titered by indirect immunofluorescence. The data suggest that 1) P.carinii is enzootic in certain rat colonies; 2) in utero transmission is a distinct possibility; and 3) paucity of cysts does not rule out P.carinii, as trophozoites predominate in early or subclinical infections. Histologic data support the validity of CIE for noninvasive detection of P.carinii antigen. Infection with this agent may be missed by basing diagnosis upon the presence of cyst forms alone, and it may be more common than previously supposed. These data have significant implications for the natural history, diagnosis, and epidemiology of P.carinii with regard to the human host.

Although the growth characteristics of Pneumocystis carinii have been described in several cell culture systems, the response of this organism to the drugs of choice, trimethoprim-sulfamethoxazole and pentamidine isethionate, have not been described in vitro. The effect of various concentrations of drugs against P. carinii on the growth of this potentially hazardous opportunistic organism as well as the methodology for in vitro assay of these agents have been detailed. Fluorescence profiles illustrating size ranges of trophozoites and cysts derived from cell culture are described.

Using Pneumocystis carinii organisms propagated through three passages in embryonic chick epithelial lung cultures, specific antigens and antisera were prepared for use in counterimmunoelectrophoresis and indirect immunofluorescent antibody techniques. These methods proved to be specific and sensitive for the detection of P. carinii antigen and antibody, respectively, in sera, and were applied to the study of cancer patients with P. carinii pneumonitis (PCP), cancer patients without pneumonitis, and normal children. Antigenemia was detected in 95% of patients with PCP, in 15% of cancer patients without pneumonitis, and in none of the normal children tested. In cross-sectional and longitudinal studies of normal infants and children, acquisition of serum antibody to P. carinii was demonstrated to occur progressively with increase in age. By 4 years of age two thirds of the normal children were found to have antibody to P. carinii in titers of 1:16 or greater. These studies indicate that subclinical P. carinii infection is highly prevalent in normal children, analogous to other opportunistic infections where active disease is manifest predominantly in the compromised host.

Heterosexual controls were found to have significantly higher titers of immunoglobulin G antibody to Pneumocystis carinii than did patients with the acquired immunodeficiency syndrome (AIDS) and P. carinii pneumonitis, human immunodeficiency virus (HIV) antibody-positive or -negative homosexual male "gay bar" patrons, and HIV antibody-positive or -negative commercial plasma donors. The T-helper/T-suppressor lymphocyte ratios of HIV antibody-negative homosexual male gay bar patrons were slightly depressed (mean = 1.31 +/- 0.54) compared with those of heterosexual controls (mean = 1.79 +/- 0.32). In addition to other recognized factors, preexisting humoral as well as cell-mediated immune deficits before infection with HIV may help to explain the prevalence of and morbidity and mortality associated with P. carinii pneumonitis in AIDS patients.

1985;87;698a-700 Chest L L Pifer Serodiagnosis of Pneumocystis carinii. http://chestjournal.chestpubs.org/content/87/5/698a.citation can be found online on the World Wide Web at: The online version of this article, along with updated information and services ) ISSN:0012-3692 http://chestjournal.chestpubs.org/site/misc/reprints.xhtml ( without the prior written permission of the copyright holder. reserved. No part of this article or PDF may be reproduced or distributed Chest Physicians, 3300 Dundee Road, Northbrook, IL 60062. All rights of been published monthly since 1935. Copyright1985by the American College is the official journal of the American College of Chest Physicians. It has Chest

A counterimmunoelectrophoresis test for Pneumocystis carinii antigenemia was employed to assess the extent of subclinical infection or colonization with this agent in adults with infection, pulmonary disease, or malignancy and in healthy homosexual men. Antigenemia was detected in 6 of 208 (3%) of normal controls, 3 of 28 (11%) of patients with pulmonary infection, 3 of 33 (9%) of those with chronic lung disease, 1 of 36 (3%) of patients with lung cancer, 7 of 271 (3%) of afebrile subjects with malignancy, 6 of 19 (32%) of febrile patients with malignancy, 2 of 22 (9%) of those with nonpulmonary infection, and 0 of 21 (0%) of healthy young homosexual men. These data suggest that P. carinii is a common commensal or saprophyte that becomes clinically significant only when host defenses are impaired. Antigenemia may occur intermittently during various disease states in the absence of positive clinical signs and should alert the physician to subacute infection or colonization. Treatment appears advisable when clinical data and counterimmunoelectrophoresis results concur.

Results of our study suggest that white Southern male homosexuals without clinical evidence of AIDS who patronize "gay bars" may have significant zinc deficiency and moderately depressed T-helper/T-suppressor cell ratios. No single causative factor could be identified to explain the significantly low zinc and elevated copper levels measured in whole blood, as well as the depressed OKT4/OKT8 cell ratios. Seventy-four percent of the homosexual male subjects were "recreational" drug abusers, 81% used inhalant nitrites routinely, and 41% routinely treated themselves with antibiotics. Eighty-one percent practiced active and/or passive penile-oral insertion, and 55.5% practiced both active and passive anal intercourse. Of the latter, 19% reported anal bleeding. Clinically inapparent, though statistically significant, borderline immunodeficiency and aberrant zinc and copper levels may be a consequence of multiple factors comprising the gay bar life-style.

Paired serum samples were collected from 94 children with pneumonia admitted to Goroka Hospital, Papua New Guinea. All but three of the children were aged 1-24 months. Only nine children were malnourished, with weight for age less than 70% of the Harvard median (three had weight for age less than 60% of the Harvard median). Pneumocystis carinii antigen was detected in the serum of 23 children. Twenty two children had serological evidence of recent infection with respiratory syncytial virus. Five children were probably infected with Chlamydia trachomatis at the time of the study, and there was less convincing serological evidence of current infection in a further 11 children. Five children showed a fourfold rise in antibody to Mycoplasma pneumoniae. Although only one child showed a fourfold rise in antibody to cytomegalovirus, 86 children had this antibody. No child showed a fourfold rise in antibody to Ureaplasma urealyticum or Legionella pneumophila. P carinii, respiratory syncytial virus, C trachomatis, M pneumoniae, and cytomegalovirus may be important causes of pneumonia in children in developing countries.

Pneumocystis carinii derived from infected murine lung was found to be capable of limited growth in Vero African green monkey kidney cell cultures. The observed increase in the number of cyst forms was influenced by the ratio of cysts to host cells in the inocula, duration of passage, and formulation of the cell culture media. Maximum growth was achieved by inoculating 1.3 X 10(5) cysts per 75-cm2 flask containing about 2 X 10(7) Vero cells (cyst-to-cell ratio=1:154) maintained on minimal essential medium supplemented with 2% fetal bovine serum. Under these conditions of culture, a 10.8-fold increase in cyst forms was observed during a 7-day passage in cell culture utilizing cyst-to-cell ratios ranging from 1:28 to 1:2,778.

Pneumocystis carinii-specific immune complexes were detected by immunoblot and enzyme-linked immunosorbent assay (ELISA) in 53% of sera from Acquired Immunodeficiency Syndrome (AIDS) patients with P. carinii pneumonia (PCP). Resolution of glycoprotein antigenemia (50-55 kd = dominant species) appears to correlate with successful PCP drug therapy and recovery. An epitope map has been constructed from immunoblots of P. carinii hydrolysates and from human and murine serum containing P. carinii antigens.

Because of the nephrotoxic action of trimethoprimsulfamethoxazole (TMP-SMX) in cyclosporine (CsA)-treated patients, combined with the (CsA)-treated patients, combined with the possibility of selecting resistant gram-negative or Nocardia asteroides organisms, a monitoring tool to detect early Pneumocystis carinii (PC) infection permitting a selective treatment approach is highly desirable. A review of 401 consecutive renal transplants revealed 26 cases (18 suspected and 8 histologically proved) of PC infection in 21 cadaver and 5 living-related renal recipients. The diagnosis was confirmed in 8/18 patients who were invasively studied by open-lung biopsy (1/2), bronchoscopy with transbronchial biopsy (4/9), bronchoscopy with brushing (1/2), bronchoscopy with bronchoalveolar lavage (2/5), and transpleural needle biopsy (0/1)-yielding a confirmed incidence of 2% (8/401). All positive invasive studies had been performed prior to or within 24 hr of the inception of TMP-SMX therapy. Nine of ten negative invasive studies were performed after more than 24 hr of treatment. The mean time from transplantation to the onset of clinical symptoms was 2.5 +/- 1.5 months. The infection rate would be 6.5%, assuming all 18 suspected cases would be PC-positive if studied pretreatment. In order to assess the efficacy of a variety of serologic methods of PC detection, qualitative counter-immunoelectrophoresis (CIE) for P carinii antigen (PC-Ag), IgG antibody reactive with PC (enzyme-linked immunosorbent assay [ELISA]), and a latex particle agglutination test (LPA) were performed on 279 sera; 85 sera from the 26 suspected or proved cases, 100 sera from normal age-matched controls, and 94 sera from 78 asymptomatic allograft recipients followed as outpatients. In the eight histologically proven cases, CIE was positive in only 3/8 and turned positive late in the clinical course. LPA was positive in all histologically proved cases; however, it was also positive in 60% of asymptomatic renal recipients. In cases that developed clinical disease, LPA increased in titer weeks to months prior to the onset of symptoms. Additionally, LPA titers decreased or stabilized during successful TMP-SMX therapy, providing an early therapeutic index. Measurement of anti-PC IgG was not useful per se, as it was elevated in both controls and documented PC infection. The combination of very low antibody titer (less than or equal to 1:16) with a positive or increasing LPA PC-Ag titer appeared to be disease-predictive.(ABSTRACT TRUNCATED AT 400 WORDS)

The in vitro cultivation of Pneumocystis carinii in chick lung cell culture made it possible to observe the organism proceeding through its life cycle. It provided the foundation for extensive seroepidemiologic studies, for in vitro drug screening, and for essential biological, metabolic, and morphologic research. In vitro culture made possible the discovery of P. carinii antigenemia, its biochemical nature, and its relevance to subclinical and clinical infection. Its utility in the presumptive diagnosis of P. carinii pneumonia and in monitoring responses to drug therapy illustrate the value and clinical application of basic research.

• Pneumocystis carinii antigen and IgG antibody profiles were prepared on 17 pediatric patients with acquired immunodeficiency syndrome (AIDS) with pneumonia who were examined by a variety of invasive methods for P carinii organisms. Overall, the accuracy of the antigen assay in invasively examined pediatric patients with AIDS with pneumonia was 94% (sensitivity, 100%; specificity, 90%), as antigen and invasive test results agreed in 16 of 17 patients. No statistically significant differences in IgG titer were observed between controls and patients invasively examined for P carinii , whether the organism was observed in the specimen or not. Since 38% of all serum samples referred were derived from "blood-borne" cases of AIDS, including patients who contracted AIDS as a result of both transfusion and hemophilia A, this suggests that P carinii pneumonia or P carinii pneumonia—like pneumonias may be more common in these individuals. ( AJDC 1988;142:36-39)

Serologic profiles of Pneumocystis carinii (PC) based upon incidence of antigenemia & IgG antibody (AB) titers in pediatric patients in Papua, New Guinea (NG) & Memphis, TN support the ubiquity of PC. PC IgG AB was titered by an enzyme-linked immunosorbent assay & antigenemia was detected by a counterimmunoelectrophoresis test, both developed in our laboratory. Antigen (AG) used in the ELISA test was derived from cell culture-grown PC. NG children with pneumonia (N=188) had higher anti-PC titers than U.S. controls (N=50). Those with PC AG (+) pneumonia had highest titers (geometric mean titer = 277), suggesting a specific immune response to PC. Those with PC AG (-) pneumonia (GMT=139) had higher titers than matched U.S. controls (GMT=60), perhaps reflecting more environmental exposure or differences due to socio-economic status. The extent to which PC is responsible for morbidity in multiple-agent pneumonias remains to be elucidated. Since PC is treatable, this represents a high priority goal, as the decision to treat might influence survival in critical cases. Mean AB titers were all significantly different (p=

• We performed autopsies and serologic tests in 189 subjects (152 men and 37 women) between 20 and 50 years of age with no history of immunosuppression who died unexpectedly and whose bodies were referred to the San Francisco coroner's office. Forty-eight of the 88 single men for whom addresses were available lived in areas of the city with a high incidence of the acquired immunodeficiency syndrome (AIDS). In addition, 36 of the subjects (30 men) were intravenous drug abusers. Antibody to the retrovirus associated with AIDS was present in 23 (18%) of the 121 subjects whose sera were tested. However, neither pathologic nor laboratory manifestations of AIDS were present in any of the 189 subjects who underwent autopsy. These results suggest that antibody to the retrovirus is common but subclinical manifestations of AIDS are uncommon in San Francisco, a city where the incidence of clinical AIDS is high. (Arch Intern Med1986;146:713-715)

The efficacy of commercially-prepared IV infusions of pooled human immunoglohulin G (IVIG) was evaluated in the treatment of Pneumocystis carinii pneumonia (PCP) in the immunosuppressed rat model to ascertain whether such treatment might prove feasible in the managment of pediatric subjects with PCP. Forty-eight rats were divided into six groups: (1) controls (C), (2) controls given IV human gammaglohulin infusions (C-I), (3) immunosuppressed rats given short-term cortisone (STC), (4) immunosuppressed rats given short-term cortisone and IV human gammaglobulin infusions (STC-I), (5) immunosuppressed rats given long-term cortisone (LTC), and (6) immunosupressed rats given long-term cortisone and IV human gammaglobulin infusions (LTC-I). An enzyme-linked immunosorbant assay (ELISA) was employed to monitor PC-specific endogenous and exogenously administered IgG throughout the test period and toluidine hlue ‘0’ stains were performed to determine the degree of P. carinii infection in rat lung. Lung infection analysis showed statistical equivalence in STC, STC-I, and LTC-I. However, LTC-I lungs contained significantly fewer (P