Infection with human immunodeficiency virus in the Pittsburgh transplant population. A study of 583 donors and 1043 recipients, 1981-1986

Infections After Organ Transplantation

Over the last ten to fifteen years medical and surgical advances have led to lower rates of infection and infection-related mortality in transplant recipients. Despite these advances, the process whereby one diagnoses and manages infectious problems in transplant patients has become increasingly complex. Evaluation of transplant patients with infections requires a good understanding of the intricacies of modern immunosuppressive therapy and both the typical and atypical clinical manifestations of many conventional and opportunistic pathogens. In particular, it is incumbent upon the clinicians caring for transplant patients to be familiar with the biology of cytomegalovirus and other herpes viruses, and of the prophylactic strategies that have evolved to lessen the burden of disease from these agents. Thorough knowledge is also required of common fungal pathogens and the viruses that cause chronic hepatitis. Transplant patients also should always be evaluated in the temporal context of their transplant operation, because different diseases are prevalent at different times after transplantation. Since immunosuppressive drugs modify the clinical presentation of infections is important to maintain clinical vigilance and attend to even minor new symptoms. This chapter is designed to provide a relatively concise overview of transplant infections for intensivists or other clinicians who encounter transplant patients in their practice. The references encompass much of the classic transplant infectious disease literature; they are included, not only for citation, but as a bibliography for further study.

Infections in solid-organ transplant recipients

Solid-organ transplantation is a therapeutic option for many human diseases. Infections are a major complication of solid-organ transplantation. All candidates should undergo a thorough infectious-disease screening prior to transplantation. There are three time frames, influenced by surgical factors, the level of immunosuppression, and environmental exposures, during which infections of specific types most frequently occur posttransplantation. Most infections during the first month are related to surgical complications. Opportunistic infections typically occur from the second to the sixth month. During the late posttransplant period (beyond 6 months), transplantation recipients suffer from the same infections seen in the general community. Opportunistic bacterial infections seen in transplant recipients include those caused by Legionella spp., Nocardia spp., Salmonella spp., and Listeria monocytogenes. Cytomegalovirus is the most common cause of viral infections. Herpes simplex virus, varicella-zoster virus, Epstein-Barr virus and others are also significant pathogens. Fungal infections, caused by both yeasts and mycelial fungi, are associated with the highest mortality rates. Mycobacterial, pneumocystis, and parasitic diseases may also occur.

Indications for and timing of liver transplantation

The tremendous success of OLT as a highly effective treatment for patients with end-stage liver disease has resulted in a rapid increase in the number of candidates for the procedure. Refinements in organ preservation, improvements in surgical technique and immunosuppression, and better postoperative management have contributed to improved survival rates. The discrepancy between the paucity of organs and the increasing numbers of potential recipients will continue to worsen until there are extraordinary breakthroughs in providing alternatives to human whole-organ livers, such as xenografts or cultured hepatocyte infusions. For now, the vast majority of patients with life-threatening liver disease are not likely to receive a liver graft. Thus, the issues of patient selection and timing of OLT have become even more relevant. Prompt referral to a transplant center is not only in the patient's best interest, but also it has been shown to be cost-effective. Over the last 30 years, it has become clear that hepatic malignancy, initially a common reason for OLT, should be an indication for transplantation only in highly selected individuals. The role of adjuvant chemotherapy needs to be defined, and proven treatment alternatives need to be developed. New antiviral agents may enable a large group of patients with chronic hepatitis B to be successfully transplanted, placing even greater demands on the already limited supply of donor livers. Hepatitis B appears to be species specific, and it is conceivable that xenotransplantation from a nonsusceptible donor species may confer protection to HBV reinfection, eliminating the problems of an inadequate donor supply. Until novel approaches, including xenotransplantation, gene therapy, or replacement of hepatic function by cultured hepatocyte infusions, become a widespread reality, future allocation policies may highlight outcome as well as urgency as a fundamental variable to determine if transplantation is reasonable. Survival rates have been shown to fall with advancing levels of urgency, resulting in a conflict between equity and efficacy in organ allocation. As waiting lists for liver transplantation continue to grow, it is becoming increasingly apparent that patients must be referred to a transplant center earlier in the course of liver disease.

Effects of total lymphoid irradiation on SIV-infected macaques

The identification of antiretroviral drugs that prevent, or delay for extended periods, progression of HIV-related disease has been of limited success. Because the number of HIV-infected people continues to increase, other therapeutic approaches must be tested. Using simian immunodeficiency virus (SIV)-infected macaques in a feasibility study, total lymphoid irradiation (TLI) was administered in fractionated doses to the supradiaphragmatic and then the infradiaphragmatic lymph nodes until a cumulative dose of 34.2 Gy was achieved in each field. During treatment and for more than 1 year of follow-up, the effects of TLI on various virological, hematological, and immunological parameters were evaluated and compared to those of similarly treated, uninfected macaques. Despite sustained low numbers of CD4+ lymphocytes (< 100/microliters blood) during treatment, TLI was well tolerated, did not result in intercurrent infections, and more importantly, induced a transient decrease in viral burden and did not exacerbate disease. Remarkably, this lack of disease progression and apparent containment of SIV replication were maintained despite persistent failure of PBMCs to respond to mitogen stimulation. Because SIV (and HIV) requires activated lymphocytes to replicate, failure of PBMCs to respond fully to stimuli may have contributed to restricting virus replication. This idea was supported by in vitro experiments in which infection of PBMCs before TLI produced higher levels of cell-free SIV than those obtained during or after TLI. Last, repopulation of peripheral blood and lymph nodes with lymphocytes paralleled that observed in uninfected control animals. The results indicate that (1) immunosuppression alone is not sufficient to induce progression to AIDS, (2) SIV infection does not undermine the ability of the immune system to regenerate new cells during the clinically latent phase, and (3) further evaluation of TLI or other immunosuppressive regimens as potential therapies for HIV disease is warranted.

Analysis of lymphocyte subsets in a renal allograft recipient infected with human immunodeficiency virus

OBJECTIVE

To study the change in lymphocyte subsets of a renal allograft recipient who acquired human immunodeficiency virus (HIV) infection.

PATIENT AND METHODS

A 53-year-old Japanese man who acquired HIV infection at the time of renal transplantation and died from opportunistic infection 3 years later was studied. Lymphocyte subsets were examined serially throughout his clinical course.

RESULTS

The numbers of CD4 positive cells were severely decreased but those of CD8 positive cells were stable; the CD 4/8 ratio was extremely low. The numbers of B cells were also decreased but production of immunoglobulin was increased. In spite of this immunosuppressive state, graft rejection was noted when the patient's immunosuppressive medication was reduced.

CONCLUSION

The lymphocyte subsets of renal transplant patients with HIV infection should be closely observed, as should the nature and timing of opportunistic infection in relation to transplantation, and the administration of immunosuppressive medication.

Is a positive western blot proof of HIV infection?

It is currently accepted that a positive Western blot (WB) HIV antibody test is synonymous with HIV infection and the attendant risk of developing AIDS. In this communication we present a critical evaluation of the presently available data on HIV isolation and antibody testing. This evidence indicates that: (1) the antibody tests are not standardized; (2) the antibody tests are not reproducible; (3) the WB proteins (bands) which are considered to be encoded by the HIV genome and to be specific to HIV may not be encoded by the HIV genome and may in fact represent normal cellular proteins; (4) even if the proteins are specific to HIV, because no gold standard has been used to determine specificity, a positive WB may represent nothing more than cross-reactivity with non-HIV antibodies present in AIDS patients and those at risk. We conclude that the use of antibody tests as a diagnostic and epidemiological tool for HIV infection needs to be reappraised.

Prevention of transmission of HIV by organ and tissue transplantation. HIV testing protocol and a proposal for recommendations concerning donor selection

Human immunodeficiency virus (HIV) can be transmitted by solid organ and some forms of tissue transplantation. Although routine screening of organ and tissue donors for anti-HIV antibodies was implemented in most Western European countries and North America in 1985, several recent case reports indicate that a definite, albeit very small, risk of HIV transmission still remains. The screening tests that are currently used cannot rule out a false-negative test result occurring during the window period. Moreover, massive transfusion of the donor during the donor procedure may result in an undetectable anti-HIV antibody titer (by dilution of donor blood) that consequently leads to a false-negative test result. These risks of HIV transmission via transplantation and important issues in HIV testing are discussed in detail. Furthermore, several recommendations for the prevention of transmission and a protocol for HIV testing for both organ and tissue donation are presented. These may serve as intermediary guidelines until official ones, such as already exist for blood donation, are defined by the transplantation communities. The exclusion of donors whose behavior may place potential recipients at risk for HIV infection is essential. A thorough heteroanamnesis of the donor's next of kin during the donor procedure should provide sufficient information about donor history to enable a decision to be made in this respect. Special attention is given to the question of whether the existing donor selection criteria for blood donation should be applied in a similar way to organ donation since the strict application of selection criteria may limit the number of available donor organs.(ABSTRACT TRUNCATED AT 250 WORDS)

Combined use of an immunotoxin and cyclosporine to prevent both activated and quiescent peripheral blood T cells from producing type 1 human immunodeficiency virus

Two different populations of infected T cells are present in human immunodeficiency virus (HIV)-infected individuals: activated cells that produce virions and quiescent cells that harbor the viral genome but are unable to produce virus unless they are activated. Using an in vitro model of acute HIV infection, we have evaluated the effect of depleting activated T cells with an immunotoxin and subsequently inhibiting activation of quiescent T cells with an immunosuppressive agent. CD25 (Tac, p55), the alpha chain of the interleukin 2 receptor, is expressed on activated, but not quiescent, T cells. An anti-CD25-ricin A chain immunotoxin eliminated activated, CD25+ HIV-infected cells and, thereby, inhibited viral production by these cells. Subsequent addition of cyclosporine to the residual CD25- cells prevented their activation and thereby suppressed their ability to produce virus and to propagate the infection to uninfected T cells.

Liver transplantation: an unheralded probable risk for tuberculosis

We present a patient who underwent orthotopic liver transplantation and died of previously undiagnosed pulmonary tuberculosis (TB). TB is known to complicate liver transplantation in rare circumstances. Liver transplantation is an unheralded risk factor for development of TB because of possible activation of latent infection or primary TB in immunosuppressed hosts. A tuberculin skin test should always be performed preoperatively. Preventive treatment with isoniazid is indicated when immunosuppressive therapy is started in patients with high TB risk. Radiographic signs of previous granulomatous disease may be important when tuberculin skin test is negative, unknown or anergy is present. TB is preventable--with a high degree of suspicion where TB is endemic and proactive programs, most TB cases in transplant recipients can be avoided.

New developments in serologic screening of corneal donors for HIV-1 and hepatitis B virus infections

PURPOSE

The authors evaluated different methods to serologically screen potential cadaveric corneal donors for human immunodeficiency virus type 1 (HIV-1) and hepatitis B virus (HBV) infections.

METHODS

Three commercially available enzyme-linked immunosorbent assays (ELISAs) for antibodies against HIV-1, a supplemental ELISA test for HIV antigen, and a radioimmunoassay and two ELISAs for hepatitis B surface antigen were compared using serum from cadavers with acquired immune deficiency syndrome (AIDS), cadavers with high risk factors for HIV infection, and cadavers with no known risk of HIV infection, along with respective confirmatory testing.

RESULTS

The ELISA tests for HIV antibodies from Abbott Laboratories, Electro-nucleonics, and Organon-Teknika showed sensitivities of 94.3%, 94.3%, and 97.1%, respectively, compared with the autopsy diagnosis of AIDS in 35 cadavers. The sensitivities of the HIV-1 antibody ELISAs ranged between 73% and 87% compared with positive Western blots in testing 118 sera from cadavers at high risk of HIV-infection, but not manifesting AIDS at the time of death. Supplemental ELISA testing for HIV-1 antigen, in an effort to close the seronegative window, failed to identify any HIV antigen-positive sera confirmed by neutralization that were not also positive for antibodies to HIV-1 by ELISA and Western blot. The ELISA for HBV surface antigen had an overall sensitivity of 92.9% and specificity of only 81.3% compared with radioimmunoassay in testing 409 sera. Monoclonal ELISAs for HIV-1 antigen and HBV surface antigen paradoxically had lower specificity than polyclonal ELISAs, with false positivity correlating with hemolysis and with increasing death to puncture time.

CONCLUSION

ELISA testing for antibodies against HIV-1 is relatively but not absolutely effective, should be accompanied by historical screening for risk factors, and does not appear to benefit from supplemental ELISA testing for HIV-1 antigen. ELISA testing for HBV surface antigen has lower specificity in screening cadaveric sera when compared with radioimmunoassay.

Transmission of human immunodeficiency virus type 1 from a seronegative organ and tissue donor

BACKGROUND

Since 1985, donors of organs or tissues for transplantation in the United States have been screened for human immunodeficiency virus type 1 (HIV-1), and more than 60,000 organs and 1 million tissues have been transplanted. We describe a case of transmission of HIV-1 by transplantation of organs and tissues procured between the time the donor became infected and the appearance of antibodies. The donor was a 22-year-old man who died 32 hours after a gunshot wound; he had no known risk factors for HIV-1 infection and was seronegative.

METHODS

We reviewed the processing and distribution of all the transplanted organs and tissues, reviewed the medical histories of the donor and HIV-1-infected recipients, tested stored donor lymphocytes for HIV-1 by viral culture and the polymerase chain reaction, and tested stored serum samples from four organ recipients for HIV-1 antigen and antibody.

RESULTS

HIV-1 was detected in cultured lymphocytes from the donor. Of 58 tissues and organs obtained from the donor, 52 could be accounted for by the hospitals that received them. Of the 48 identified recipients, 41 were tested for HIV-1 antibody. All four recipients of organs and all three recipients of unprocessed fresh-frozen bone were infected with HIV-1. However, 34 recipients of other tissues--2 receiving corneas, 3 receiving lyophilized soft tissue, 25 receiving ethanol-treated bone, 3 receiving dura mater treated with gamma radiation, and 1 receiving marrow-evacuated, fresh-frozen bone--tested negative for HIV-1 antibody. Despite immunosuppressive chemotherapy, HIV-1 antibody appeared between 26 and 54 days after transplantation in the three organ recipients who survived more than four weeks.

CONCLUSIONS

Although rare, transmission of HIV-1 by seronegative organ and tissue donors can occur. Improvements in the methods used to screen donors for HIV-1, advances in techniques of virus inactivation, prompt reporting of HIV infection in recipients, and accurate accounting of distributed allografts would help to reduce further this already exceedingly low risk.

Thalidomide in human immunodeficiency virus (HIV) patients. A review of safety considerations

The sedative thalidomide was withdrawn from the market 30 years ago because of its teratogenic and neurotoxic adverse effects. The compound was later discovered to be extremely effective in the treatment of erythema nodosum leprosum, a complication of lepromatous leprosy. This effect is probably due to a direct influence on the immune system, because thalidomide possesses no antibacterial activity. The compound is presently used as an experimental drug in the treatment of a variety of diseases with an autoimmune character, including recurrent aphthosis of nonviral and nonfungal origin in human immunodeficiency virus (HIV) patients. This article reviews the most important chemical and pharmacokinetic properties of thalidomide. The possible mechanisms of the nonsedative effects of thalidomide with respect to the safety of its use in HIV patients are discussed. Because the mechanism of the immunomodulatory effect of thalidomide is unknown, the possibility that the administration of this compound will accelerate the deterioration of the immunological status of HIV patients cannot be excluded. Clinical evidence suggests that thalidomide may aggravate the condition of patients with preexisting peripheral neuropathy. Hypersensitivity reactions to thalidomide may occur more frequently in HIV patients than in other patient groups. Because of the teratogenic activity of thalidomide, reliable contraception must be provided to female patients of childbearing age. Before the introduction of thalidomide therapy to an HIV patient presenting with oral ulcers, a fungal or viral origin of the lesions should be excluded. Thalidomide should not be used in patients with preexisting HIV-related peripheral polyneuropathy, polyradiculopathy or encephalopathy. In patients experiencing a complete remission, the discontinuation of thalidomide treatment and its reintroduction in the case of a relapse are preferable to maintenance therapy.

Use of potentially infected donor hearts for cardiac transplantation

Despite the nationwide shortage of heart donors, more patients, some of whom are critically ill, are being accepted as candidates for transplantation. Thus, on occasion, we have liberalized our donor criteria to meet the demand. We have recently transplanted 16 potentially infected donor hearts into critically ill recipients. Of these 16 donors, 7 had multiple positive blood cultures as follows: Streptococcus pneumoniae (3), Staphylococcus aureus (2), Klebsiella pneumoniae (1), and Enterobacter sp (1). Seven other donors were accepted despite high fevers (rectal temperature greater than 38.9 degrees C), leukocytosis (greater than 18 x 10(9)/L [greater than 18,000 cells/microL]), and pulmonary infiltrates with positive sputa (Enterobacter [3], Klebsiella pneumoniae [2], and Staphylococcus [2]). Two other donors with hepatitis B surface antigen positivity were deemed at high risk but were used because the recipients were in immediate need. Early mortality (less than or equal to 30 days) among the recipients was 3/16 (18.7%) with 1 patient dying of uncontrolled allograft rejection, 1 of hepatic failure, and 1 of Pseudomonas septicemia. Late mortality (greater than 30 days after operation) occurred in 6 patients: 2 patients died of hepatic failure, 3 died of graft atherosclerosis, and 1 died of iatrogenic hemorrhage after a liver biopsy. Only 1 patient died of infection unrelated to that of the donor, and the other patients had no infectious complications resulting from the organisms identified in their respective donors. Use of potentially infected donor hearts resulted in surprisingly few infectious complications in this group of recipients. This practice can be safe and should be considered when other options are unavailable.

Current status of renal transplantation

The success rate of renal transplantation has improved considerably during the past decade, with substantial improvements in both graft and patient survival. The quality of graft function, however, and not graft survival alone is increasingly determining the standards by which transplantation outcome is being judged. As the demand for kidney transplants continues to rise and transplants are being offered to an ever-increasing number of patients, organs are being sought from new supply pools and efforts are being made to use current resources more efficiently. Improvements in clinical management have allowed short-term complications such as infection and rejection to be better prevented or better diagnosed and treated. Fundamental advances in the understanding of the immunologic processes underlying both allograft rejection and acceptance and the introduction of new immunosuppressive agents have allowed a better use of drug therapy and have moved the goal of acquired transplant tolerance closer to attainment. With improved initial transplant success rates, the long-term transplantation outcome is becoming more important. The role of tissue matching in preventing chronic rejection is becoming more appreciated, and the long-term risks of malignancy, arteriosclerosis, and chronic rejection are being better recognized and managed.

HIV testing in patients with end stage renal disease

One hundred and twenty eight British and Irish nephrologists were questioned about their policy for HIV testing of patients with end stage renal failure being considered for renal replacement therapy. A total of 101 (79%) replied. In the case of candidates for dialysis roughly one third of respondents tested only people they considered at risk of infection with HIV and nearly one fifth considered testing unnecessary. In the case of candidates for transplantation routine HIV testing was carried out by 68 of 100 nephrologists; 22 tested only patients "at risk" and 10 did not test. A positive HIV test result was considered by most but not all respondents (63/86) to exclude patients from transplantation. Twenty four of 88 nephrologists considered that HIV positivity should exclude patients from haemodialysis, but only seven of 87 would exclude such patients from peritoneal dialysis. Similar attitudes pertained for patients with end stage renal failure who refused HIV testing. Testing with the patient's knowledge and consent was the policy of two thirds of nephrologists, but a patient's signature was obtained by only 24 of 88. There should be a consensus on practice for HIV testing of patients with end stage renal failure.

Transplantation in HIV+ patients

Twenty-five whole-organ recipients treated from 1981 through September 1988 were HIV carriers. Eleven were infected before transplantation, although this was not known until later in 8 recipients. The other 14 were infected perioperatively. Ten of the 25 recipients were infants or children. The organs transplanted were the liver (n = 15), and the heart or kidney (n = 5, each). After a mean follow-up of 2.75 years (range, 0.7-6.6 years), 13 recipients are alive. Survival is 7/15, 2/5, and 4/5 of the liver, heart, and kidney recipients, respectively. The best results were in the pediatric group (70% survival) in which only 1 of 10 patients died of AIDS. In contrast, AIDS caused the death of 5 of 15 adult recipients and was the leading cause of death. Transplantation plus immunosuppression appeared to shorten the AIDS-free time in HIV+ patients as compared to nontransplant hemophiliac and transfusion control groups. Accrual of HIV+ transplant recipients has slowed markedly since the systematic screening of donors, recipients, and blood products was begun in 1985.

Liver transplantation (1)

Advances in the management of both chronic and acute hepatic disease have been made possible and even mandated by the development of liver transplantation. The clinical use of transplantation has proceeded at a rapid pace since a Consensus Development Conference of the National Institutes of Health concluded in June 1983 that liver transplantation had become a service and not simply an experimental procedure.1

The liver can be transplanted as an extra (auxiliary) organ at an ectopic site, or in the orthotopic location after the removal of the host liver (Fig. 1 ). This article will focus primarily on the orthotopic procedure. However, there has been renewed interest in the auxiliary operation, which will be discussed separately.