Pneumocystis carinii

Pneumocystis carinii pneumonia

Pneumocystis carinii pneumonia (PCP) remains an important complication of AIDS. Advances have been made in establishing the taxonomy of the organism but the life cycle of the organism and pathogenetic mechanisms of disease remain obscure. In HIV patients the incidence of PCP has decreased because of widespread use of prophylaxis and survival of those with PCP has improved with use of adjunctive corticosteroid therapy. Less toxic drug therapies are still needed as well as better noninvasive diagnostic techniques.

Pneumocystis carinii pneumonia in cancer patients

Concern has been arisen about the recently reported increasing incidence of PCP in patients with cancer and the potential transmissibility of this infection. Whether or not there is an increase in the incidence of P. carinii infections, PCP should be considered in the differential diagnosis of pulmonary infiltrates in bone marrow transplant recipients, in patients with hematologic neoplasms and in patients with primary or metastatic brain neoplasms. Intensity of immunosuppression plays a crucial role, especially long-term (> 2 months) corticosteroid treatment. PCP is usually manifested clinically during augmentation or during tapering of corticosteroid dose. Thus, if the chest radiograph of a high-risk patient shows diffuse infiltrates, bronchoscopy and bronchoalveolar lavage should be done immediately. Treatment options are the same as for the AIDS population, except that TMP-SMX is tolerated better in non-AIDS patients. The role of supportive care, including mechanical ventilation in such patients should not be underestimated. Oral therapy with dapsone-trimethoprim or with atovaquone, can be as effective as conventional therapy in mild disease, permitting treatment on an outpatient basis. PCP is often preventable and our understanding has improved about when prophylaxis should be initiated. In the future, the emergence of new technologies for diagnosis and of new agents for treatment and prophylaxis, will bring us closer to the goal of controlling this serious infection.

Pneumocystis carinii pneumonia in patients without predisposing illnesses. Acute episode and follow-up of five cases

Pneumocystis carinii pneumonia (PCP) is described almost exclusively in immunocompromised hosts. This report describes our experience with acute episodes and the follow-up of five patients with PCP who had no known predisposing conditions. The average follow-up period was 3.6 years (range, 2.6 to 4 years). Lymphocyte subpopulations (CD4, CD8, and CD4:CD8), serum immunoglobulins (IgG, IgM, and IgA), and serologic studies for human immunodeficiency virus were carried out on all patients at least twice, both at the beginning and the end of the follow-up. None of the patients presented compatible data with AIDS or any other identifiable risk factors. We conclude that PCP can occur in patients who apparently do not have immunosuppression.

Changes in hospital admissions pattern in patients with human immunodeficiency virus infection in the era of Pneumocystis carinii prophylaxis

BACKGROUND

Pneumocystis carinii pneumonia (PCP) was the leading cause of hospital admissions in patients with human immunodeficiency virus (HIV) infection before the widespread use of PCP prophylaxis. We studied retrospectively the changes in annual hospital admission patterns after the start of a population-based PCP prophylaxis program in Toronto. The purpose of the study was to identify the cogent diseases requiring hospitalization of HIV patients in the current era of PCP prophylaxis. This information is important for the allocation of health care resources in the future as well as for targeting research in the prevention of specific HIV-related diseases.

METHODS

The annual HIV-related hospital admissions before and after the start of the Toronto aerosol pentamidine program (May 1989) were studied. All admission records due to AIDS-defining illnesses or occurring in patients with known HIV status in three major referral centers were reviewed. The two periods for comparison were May 1988 through April 1989 and May 1989 through April 1990. The data obtained were stratified according to the following: (1) cause of the illness prompting hospital admission; (2) PCP admissions; and (3) admissions according to the major organ system involved. These categoric data were compared by nonparametric chi 2 tests.

RESULTS AND CONCLUSIONS

Population-based prophylaxis of PCP with aerosol pentamidine resulted in a significant reduction in the total number of PCP hospital admissions. Infection remains the principal cause of hospital admission in HIV patients after the start of the PCP prophylaxis program. However, there was an increase in the proportion of hospital admissions due to nonrespiratory-related infections. There was also a modest increase in admissions due to neurologic and gastrointestinal diseases. Central nervous system lymphoma and cytomegalovirus retinitis accounted for the majority of the rise in the nervous system. These data suggest there is a changing pattern of the diseases leading to the hospitalization of patients with HIV infection in the era of PCP prophylaxis.

Radiology of AIDS in the pediatric patient

The Acquired Immunodeficiency Syndrome (AIDS) has involved the pediatric age group and is especially prevalent in babies born of mothers who are intravenous drug abusers or prostitutes. Approximately 30% of children born to mothers who are seropositive for the human immunodeficiency virus (HIV) will develop HIV infection. There are several important differences in children and adults with AIDS. The incubation period of the disease is shorter, and initial clinical manifestations occur earlier in children. In addition, certain infections are more common in children, and the different types of malignancy, especially Kaposi's sarcoma, are unusual in the pediatric age group. The altered immune system involves both T cells and humoral immunity and increases susceptibility to a variety of infections, particularly opportunistic organisms. In this publication the complications of pediatric AIDS involving the lungs, cardiovascular system, gastrointestinal tract, genitourinary system, and neurological system are described. The most common pulmonary complications in our experience are Pneumocystis carinii pneumonia and pulmonary lymphoid hyperplasia. The spectrum of cardiovascular involvement in pediatric AIDS includes myocarditis, pericarditis, and infectious endocarditis. Gastrointestinal tract involvement is usually due to opportunistic organisms that produce esophagitis, gastritis, and colitis. Abdominal lymphadenopathy is a common finding either due to disseminating Mycobacterium avium-intracellulare infection or nonspecific lymphadenopathy. Although cholangitis is more commonly seen in adults, it may occur in children with AIDS and, in most cases, is due to related opportunistic infections. Genitourinary infections may be the first evidence of HIV disease. Cystitis, pyelonephritis, renal abscesses, and nephropathy with renal insufficiency are complications of pediatric AIDS. A variety of neurological abnormalities may occur in pediatric AIDS. The most common cause of neurological dysfunction in children with AIDS is HIV neuropathy. We present the many complications of AIDS in children demonstrated by a variety of imaging modalities, emphasizing the importance of diagnostic imaging in children with this disease.

Improvement of pulmonary gas exchange after surfactant replacement in rats with Pneumocystis carinii pneumonia

The effect of intratracheal surfactant instillation on pulmonary function in rats with pneumocystis carinii pneumonia (PCP) was investigated. In these animals which developed PCP with severe respiratory failure after s.c. administration of cortisone acetate over 8-12 weeks, pulmonary function could be improved by surfactant instillation, as measured by an increase in PaO2. Histological examination showed that alveoli of rats with PCP which received no surfactant treatment are filled with foamy edema, whereas after surfactant treatment alveoli are stabilized and well-aerated. These results indicate that surfactant therapy could be used in patients with severe PCP to overcome an acute stage of respiratory distress while at the same time surfactant could serve as a carrier substance for antimicrobial drugs to attain high intra-alveolar and low systemic antimicrobial drug concentrations.

Effect of surfactant replacement on Pneumocystis carinii pneumonia in rats

The effect of intratracheal surfactant instillation on pulmonary function in rats with Pneumocystis carinii pneumonia (PCP) was investigated. In those animals which developed PCP with severe respiratory failure after administration of cortisone acetate s.c. over 8-12 weeks, pulmonary function was improved by surfactant instillation. PaO2 values 30 min after surfactant instillation were significantly higher compared to pretreatment values and also compared to PaO2 values of rats 30 min after receiving saline (482.9 mmHg +/- 44.7, 170.7 mmHg +/- 39.3 and 67.2 mmHg +/- 17.4, respectively). Histological examination showed that alveoli of rats with PCP which received no exogenous surfactant are filled with foamy edema, whereas after exogenous surfactant alveoli are stabilized and well-aerated. These results indicate that exogenous surfactant may help patients with severe PCP to overcome an acute stage of respiratory distress.

Survival trends of people with AIDS in Washington State

Survival rates of 609 cases of acquired immunodeficiency syndrome (AIDS) in Washington State diagnosed between 1982 and 1987 according to pre-1987 AIDS surveillance definition were analyzed. People with a primary diagnosis of Kaposi's sarcoma survived longer than those with Pneumocystis carinii pneumonia. Both groups survived longer than those with other diagnoses. Median survival increased from 11.3, to 12.5, to 20.8 months for cases diagnosed in or before 1985, during 1986, and during 1987, respectively.

An evaluation of the use of the Statewide Planning and Research Cooperative System of New York State as a resource planning tool for HIV infection

Hospital discharge records of patients with Pneumocystis carinii pneumonia (PCP) in New York State were studied to determine whether cases of human immunodeficiency virus (HIV) infection were identified. We estimate that as many as 13 percent of hospitalizations of patients with PCP in 1987 and 10 percent of those in 1988 were not appropriately identified as HIV related. Identification of PCP as HIV related was a function of a hospital's volume of PCP admissions.

Pulmonary complications of combination therapy with cyclophosphamide and prednisone

Oral cyclophosphamide and prednisone are standard treatment for some neoplasms and necrotizing systemic vasculitis and are advocated with increasing frequency for idiopathic interstitial lung disease. During a 15-month period, we observed four cases of acute respiratory failure from Pneumocystis carinii pneumonia (PCP) in patients treated with oral cyclophosphamide and prednisone. One patient each had polyarteritis nodosa, Wegener's granulomatosis, bronchiolitis obliterans with organizing pneumonia, and chronic lymphocytic leukemia with red blood cell aplasia. Hypoalbuminemia (serum albumin level less than 3.0 g/dl) and daily therapy were associated with increased risk for development of PCP (p less than 0.05). None of the patients had leukopenia (less than 3,500/cu mm) or neutropenia (less than 1,000/cumm) at diagnosis. All were negative for the human immunodeficiency virus. Patients receiving oral cyclophosphamide and prednisone may be at higher or increasing risk for PCP. A high index of suspicion and aggressive evaluation for opportunistic infection are needed in these patients; consideration for trimethoprim-sulfamethoxazole prophylaxis and development of more quantitative measures of immunosuppression are needed.

Aerosolized pentamidine in HIV. Promising new treatment for Pneumocystis carinii pneumonia

Pneumocystis carinii pneumonia is the most common life-threatening disease diagnosed in patients infected with the human immunodeficiency virus (HIV). Patients treated for their initial episode are at risk for recurrence of the disease. HIV-positive patients with low T4 lymphocyte counts are also at risk. Conventional treatment regimens with parenteral pentamidine isethionate (Pentam 300) or trimethoprim-sulfamethoxazole have a 50% to 60% incidence of serious adverse effects and a 20% to 40% rate of failure. Aerosolized pentamidine represents a promising new therapy for HIV-infected patients. Major adverse reactions have not been reported with its use. The Food and Drug Administration's (FDA's) recent approval of aerosolized pentamidine may also have a positive effect on healthcare costs by preventing episodes of P carinii pneumonia. In addition, FDA approval may result in reimbursement of patients for this new therapy by more insurance companies.