Efforts of the United States' National Marrow Donor Program and Registry to improve utilization and representation of minority donors.

SUMMARY: Haematopoietic stem cell transplantation is often used as a therapy for patients with certain blood, metabolic or immune system disorders. The United States' National Marrow Donor Program (NMDP) works to facilitate such life-saving transplants by coordinating the donor search and match process. However, concern exists that the NMDP Registry is underutilized and under-representative of racial and ethnic minorities. African-Americans and Hispanics are somewhat under-represented within the total number of donors, and it is estimated that the Registry is used by only approximately one-third of patients needing transplants. The NMDP has instituted programmes that address such concerns, resulting in an increase in both the total number of donors and the minority representation on the Registry. It has also increased efforts to recruit donors of umbilical cord blood, often a viable alternative source of haematopoietic stem cells. Over the past 8 years, the Registry has grown by more than 30% to contain over seven million donors, and the proportional distribution of racial and ethnic groups on the Registry has steadily approached their proportional distribution in the US population. Continued efforts on the part of the NMDP to maintain a Registry that is large in number and ethnically diverse should help ensure access to haematopoietic stem cell transplants for all patients who need them. The procedures and experience of the NMDP and its Registry may have implications for registries elsewhere in the world as they confront similar issues of number and diversity.

Aspergillus infection of the central nervous system in patients with acquired immunodeficiency syndrome.

Infections of the central nervous system in patients with the acquired immunodeficiency syndrome are common. Of the many microorganisms that have been implicated, infection with Aspergillus is rare. We describe three patients with Aspergillus infection of the nervous system. Two patients had cerebral lesions due to Aspergillus flavus, and one patient had Aspergillus fumigatus infection of the spinal cord. Diagnosis of the infections was difficult, and therapy appeared to be ineffective.

Infection after liver transplantation.

Infections occurring in liver transplant recipients result in significant morbidity and mortality. Factors influencing the frequency of posttransplant infections include pretransplant nutritional status, latent viral infections, and the degree of immunosuppression used to modulate the immune response to the allograft. Infectious agents may be introduced into the patient via the allograft, through infusion of blood products, and through intravenous lines, catheters, and drains. Infections also develop as a result of reactivation of latent viruses or by overgrowth or invasion by endogenous organisms. The intensity of the immunosuppressive regimen directly affects the frequency of infection. Infection may be categorized as bacterial, viral, fungal, or protozoal. The most frequent organisms include bacterial--enterobacteriaceae; viral--cytomegalovirus; fungal--Candida species and Aspergillus species; and protozoal--Pneumocystis carinii. Diagnosing infection requires the use of many different methods in combination, including routine bacterial culture, viral culture, and fungal culture. Histologic and cytologic examination may lead to rapid identification of some organisms. Specialized collection procedures such as bronchoalveolar lavage provide rapid access to material for culture and cytologic examination. Serum serology in conjunction with histotopic or cytologic evaluation is useful in diagnosing some infections, such as Epstein-Barr virus. New technology such as polymerase chain reaction allows detection of all types of infection at or before the onset of clinical symptoms. Rapid and early diagnosis of infection in this patient population can reduce infection-related morbidity and mortality.

Successful prophylaxis of cytomegalovirus disease after primary CMV exposure in liver transplant recipients.

UNLABELLED: During a 38-month period, we studied 320 liver transplants in 283 recipients (202 adults, 81 children). CMV disease was documented in 85 patients (30.0%) The major risk factor for CMV disease was primary CMV exposure (transplanting a seropositive allograft into a seronegative recipient). A total of 42 patients (14.8%) had primary CMV exposure. Twenty-one patients were historical controls, while the next 21 received prophylaxis for CMV infection in a nonrandomized trial of consecutive study groups. The regimen of prophylaxis consisted of intravenous immune globulin (IgG; 0.5 g/kg) at weekly intervals for 6 weeks and acyclovir for 3 months. CMV prophylaxis resulted in a dramatic reduction in the incidence of CMV disease (71.4% vs. 23.8%, (P less than 0.01). All cases of CMV were treated with intravenous ganciclovir (5 mg/kg b.i.d. for 14 days), with 5 patients in the control group developing recurrent CMV disease (33.3% relapse). In the 16 patients receiving prophylaxis who did not develop CMV disease, all developed positive CMV-IgG titers with the passive administration of IgG. However, none developed any evidence of CMV infection or viral shedding as assessed by IgM titers and surveillance viral cultures. Four deaths occurred (all control patients), but none were related to CMV disease. Overall patient and graft survivals after primary CMV exposure were 90.5% and 82.2%, respectively, after a mean follow-up of 14 months. CONCLUSION: Primary CMV exposure is a major risk factor for CMV disease in liver transplant recipients. Intravenous IgG plus acyclovir is safe and effective in preventing CMV infection and disease in this setting. Because of the scarcity of donor organs, we do not advocate protective matching to avoid primary CMV exposure but rather recommend prophylaxis to prevent CMV disease in this high-risk group.

Fatal pericarditis due to Mycobacterium avium-intracellulare in acquired immunodeficiency syndrome.

A 27-year-old white male homosexual with AIDS presented 19 months after the initial diagnosis with persistent fever, marked dyspnea at rest, and severe substernal pain in the chest. A pericardial friction rub was auscultated, and an effusion was demonstrated echocardiographically. Pericardiocentesis yielded 220 ml of serosanguinous fluid. Special stains of the fluid for microorganisms were negative. A mycobacterial infection was suspected, and therapy with multiple antimycobacterial agents was initiated. Cultures of the fluid eventually yielded MAI. Despite therapy, cardiac function declined, and the patient died two months after presentation. Autopsy confirmed the diagnosis of chronic pericarditis due to MAI. Pericarditis due to MAI should be included in the differential diagnosis of cardiac dysfunction in patients with AIDS.

Detection of cytomegalovirus in bronchoalveolar lavage specimens. Spin amplification and staining with a monoclonal antibody to the early nuclear antigen for diagnosis of cytomegalovirus pneumonia.

To diagnose cytomegalovirus pneumonia in a hetergeneous population of patients, three methods for detection of CMV in bronchoalveolar lavage specimens were compared as follow: (1) spin amplification followed by staining with a monoclonal antibody to the early nuclear antigen (EA-assay); (2) conventional tissue cell culture; and (3) cytology. Cell differentials were performed on most specimens. Cytomegalovirus was detected by one or more method in 55 BAL specimens from 39 patients. Cytomegalovirus (CMV) pneumonia was diagnosed by lung tissue (primarily autopsy) histologic findings and conventional culture results or the presence of CMV in extrapulmonary tissue, fulfillment of specific clinical and radiographic criteria plus failure to recover a pathogen other than CMV from a respiratory specimen. Probable CMV pneumonia was diagnosed if only the latter two criteria were met. The EA-assay was positive in all patients with proven or probable CMV pneumonia and in 92 percent of those without documented pneumonia. Cytologic findings were positive only in patients with CMV pneumonia but were negative in one-third of those patients. As a diagnostic test for CMV pneumonia, the EA-assay, conventional culture, and cytology had positive predictive values of 45, 57, and 100 percent, respectively. Lymphocyte percentages in BAL specimens from patients with CMV pneumonia were significantly decreased compared with those of patients without CMV pneumonia (p less than 0.005). Although the EA-assay should not be used alone as a diagnostic test for CMV pneumonia in our patient population, the combination of alveolar lymphopenia and a positive BAL CMV EA-assay was highly suggestive of disease.

Failure of the sterile air-flow component of a protected environment detected by demonstration of Chaetomium species colonization of four consecutive immunosuppressed occupants.

Four bone marrow transplant recipients consecutively occupying the same room on our Oncology-Hematology Special Care Unit (OHSCU) became colonized with Chaetomium species between January and April, 1987. These patients, aged 27 to 43 years, were immunocompromised as a result of intensive chemotherapy, and were consequently at increased risk for development of invasive fungal infection. At the time of Chaetomium colonization, all patients were febrile, two had transient new infiltrates on chest x-ray, and three were receiving amphotericin B therapy. Subsequent environmental cultures revealed Chaetomium contamination of the OHSCU air-handling system, including the HEPA (high-efficiency particulate air) filters in seven of the nine rooms comprising the unit. Because fungal colonization of HEPA filters used to create a "protective environment" for immunocompromised patients can occur and can serve as a source for patient infections, guidelines concerning proper surveillance of these HEPA filters should be established. We suggest that before a new patient enters a "protected" room, the clean side of the HEPA filter should be cultured. If fungi are recovered from that culture, we would recommend changing the filter.

Nosocomial invasive aspergillosis in lymphoma patients treated with bone marrow or peripheral stem cell transplants.

OBJECTIVES: To determine the prevalence of aspergillosis in lymphoma patients housed in a protective environment while undergoing a bone marrow transplant or peripheral stem cell transplant and its relation to lymphoma type, type of transplant, period of neutropenia, method of diagnosis, species of Aspergillus, and the use of empiric amphotericin B. DESIGN: Clinical, autopsy, and microbiology records were reviewed retrospectively to determine the presence or absence of invasive aspergillosis. All positive specimens underwent further review to determine parameters outlined above. SETTING: The review took place at the University of Nebraska Medical Center with lymphoma patients housed in the oncology/hematology special care unit, which consists of 30 single-patient rooms under positive pressure with high-efficiency particulate air filtration. PATIENTS: 417 lymphoma patients admitted to the oncology/hematology special care unit who underwent 427 courses of high-dose chemotherapy with or without total body irradiation followed by a stem cell rescue. RESULTS: Twenty-two cases (5.2%) of nosocomial invasive aspergillosis (14 caused by Aspergillus flavus, 2 by Aspergillus terreus, 2 by Aspergillus fumigatus, and 4 by characteristic histology) were diagnosed. The prevalence of disease according to transplant was 8.7% for allogeneic bone marrow transplant (2/23 treatments), 5.6% for autologous peripheral stem cell transplant (9/161), and 4.5% for autologous bone marrow transplant (11/243). Fifteen patients were presumptively diagnosed prior to death (68.2%) most commonly by histologic examination of skin biopsies. All 22 patients received amphotericin B therapy, 17 prior to aspergillosis diagnosis, and 7 (31.8%) survived. No patient with disseminated disease survived. CONCLUSIONS: Even when housing lymphoma patients undergoing myeloablative therapy in a protective environment containing high-efficiency particulate air filtration, there was a risk of developing aspergillosis. These data also showed that antemortem diagnosis with aggressive amphotericin B therapy was most effective in the management of infected lymphoma patients when engraftment occurred and the disease did not become disseminated.

Optimal protocol for processing high-volume and Peds Plus blood cultures by the BACTEC NR860.

The optimal incubation period for blood cultures collected in high-volume (Plus 26) and anaerobic (NR7A) media or Peds Plus medium and processed by the BACTEC NR860 was evaluated during a 12-month period. Organisms were recovered from 9% (1528 of 16,870) of blood culture vials (14% [1302 of 9118] of sets). Ninety-eight percent of positive vials were detected by day 5. Thirty-three vials (Plus 26 or NR7A) became positive on day 6 or 7; all positive Peds Plus vials were detected by day 5. Therapy did not change in response to detection of the organisms (26 "occasional" pathogens, 9 "usual" pathogens) in these vials. One usual pathogen had potential clinical significance, but the patient from whom the culture was collected died before it became positive. In the author's institution, the 5-day protocol for processing blood cultures could be adopted without compromising patient care.

Automation in clinical microbiology.

Automation was introduced into the clinical microbiology laboratory in the 1960s but initially met with limited success. Today, instruments are an integral part of many clinical laboratories and are used for microbial detection, identification, and susceptibility testing; detection of positive blood cultures; screening urine samples for potential pathogens; and assaying levels of antimicrobial agents in body fluids. Automation has allowed more rapid diagnosis and elimination of the subjective interpretation of many manual tests. In addition, in some cases, automated tests are more sensitive and specific than manual techniques. However, automated testing often is more expensive than manual testing and is associated with the possibility of mechanical failure. Automation will continue to be an important part of the clinical microbiology laboratory and in the future will include more molecular biology technologies, such as the polymerase chain reaction. Perhaps practical applications of flow cytometry will be identified.

Rapid detection of cytomegalovirus by 24-well plate centrifugation with the use of a monoclonal antibody to an early nuclear antigen.

Two methods for the detection of cytomegalovirus (CMV) in 457 clinical specimens were compared: (1) centrifugal inoculation of MRC-5 cells seeded on coverslips in 24-well plates and staining with a monoclonal antibody to CMV early nuclear antigen after incubation for both 16-18 hours (EA-1) and four days (EA-4); and (2) conventional tube cell culture. CMV was identified in 50 (11%) specimens from 34 different patients. EA-1 and EA-4 had positive results for CMV in 32 (64%) and 36 (73%) of the specimens, respectively. Positive inclusions were present on only one coverslip in 31% of the cases by EA-1 and in 10% by EA-4. The number of inclusions was not necessarily predictive of tissue culture results. CMV was recovered by conventional tissue culture from 27 specimens (54%) after an average of 17 days (range, 6-26 days). One specimen, positive for CMV by EA-4, yielded herpes simplex virus (HSV), and from 9 of the 407 CMV-negative specimens, another virus was recovered: HSV from 6 specimens and varicella zoster virus, adenovirus, and enterovirus from one specimen each. CMV was detected in significantly more specimens by EA-4 than by tissue culture (P = 0.037). However, there was no significant difference in the detection of CMV between EA-1 and EA-4 or between EA-1 and conventional culture. The authors' data suggest that for maximum recovery of CMV from clinical specimens, both an early antigen assay and conventional tissue culture should be performed. For urine specimens it appears that inoculation of two coverslips followed by staining after overnight incubation is adequate. To optimize the yield of the early antigen assay when testing specimens other than urine, the authors recommend inoculating three coverslips, two of which should be stained after overnight incubation, and, if necessary, the third coverslip could be stained after a more prolonged incubation period.

Evaluation of routine anaerobic blood cultures in the BacT/Alert blood culture system.

To evaluate the use of routine anaerobic blood cultures with the BacT/Alert system, results of 12,289 blood culture sets collected from adults over a 9-month period were reviewed. Of the sets included in the study, 1,306 (10.6%) from 808 patients grew 1 or more organisms. Anaerobes were present in 39 sets from 38 patients. Of the positive sets, both bottles were positive in 60.7% of cases, the aerobic bottle only in 23.7%, and the anaerobic bottle only in 15.6%. When only the 254 patients who had 2 or more positive sets were considered, both bottles were positive in 71.5% of cases, the aerobic bottle only in 20.7%, and the anaerobic only in 7.8%. In this subset of patients gram-positive bacilli, gram-negative bacilli other than Enterobacteriaceae, and yeasts grew significantly more frequently in aerobic bottle. No organisms preferred the anaerobic bottle. These data support the selective use of the BacT/Alert anaerobic blood culture bottle in patients at risk for anaerobic bacteremia.

Clinical comparison of two assays for rapid detection of cytomegalovirus early nuclear antigen.

Three methods for detection of cytomegalovirus (CMV) in 218 clinical specimens were compared: (1) shell vial assay to detect the early nuclear antigen after incubation for 16 hours and 40 hours (Syva Company); (2) 24-well plate assay to detect the early nuclear antigen after incubation for 16 hours (DuPont); and (3) convention tissue cell culture. CMV was detected in 26 specimens (12%) by one or more of these methods. With the shell vial assay, 12 (46%) and 15 (58%) specimens were positive after incubation for 16 hours and 40 hours, respectively. CMV was detected in 17 specimens (65%) by the 24-well plate assay. There was no significant difference in the detection of CMV between these assays. CMV was identified by conventional tissue culture in 15 of 22 (68%) evaluable cultures after an average of 14.2 days. More specimens were positive by conventional culture than by the 16-hour shell vial assay (P = 0.035). For optimal detection of CMV in clinical specimens, both conventional tissue cell culture and an early antigen assay should be performed. The two early antigen assays evaluated in this study yielded comparable results. However, the 24-well plates are more easily manipulated, and the 24-well plate assay, as performed, was easier to interpret and more cost efficient.

Comparison of the Gen-Probe PACE 2 system, direct fluorescent-antibody, and cell culture for detecting Chlamydia trachomatis in cervical specimens.

A chemiluminescent-labeled DNA probe (Gen-Probe PACE 2 System) for detection of Chlamydia trachomatis in endocervical specimens was evaluated. For each specimen, tissue cell culture, direct immunofluorescent staining (DFA), and DNA probe assay were performed. Thirty of 318 (9.4%) specimens were positive for C. trachomatis. The sensitivities, specificities, and positive and negative predictive values of the DNA probe compared with cell culture were 93%, 98%, 85%, and 99%, respectively, and for DFA these same values were 81%, 99%, 83%, and 99%, respectively. The Gen-Probe PACE 2 System is a reliable method for the rapid detection of endocervical chlamydial infection.

Chlamydiazyme plus blocking assay to detect Chlamydia trachomatis in endocervical specimens.

Three methods to detect Chlamydia trachomatis in endocervical swab specimens collected from 502 women with genitourinary or abdominopelvic symptoms were evaluated: (1) a direct immunofluorescence assay, (2) an enzyme-linked immunoabsorbent assay, confirming positive samples with a blocking assay, and (3) conventional tissue cell culture. C. trachomatis was detected by at least one method in 72 specimens, of which 56 (11%) were determined to be true-positive results by repeated testing and by performing a confirmatory assay. The sensitivity, specificity, and positive and negative predictive values were 91%, 100%, 100%, and 99%, respectively, for culture and the enzyme-linked immunoabsorbent assay plus blocking assay and 74%, 98%, 83%, and 96%, respectively, for the direct immunofluorescence assay. In this population of women, using the enzyme-linked immunoabsorbent assay with the confirmatory assay is a rapid, reliable, and cost-effective alternative to culture for diagnosing infection with C. trachomatis.

Rapid identification of Staphylococcus epidermidis.

A panel of Minitek sugar disks, consisting of trehalose, mannitol, xylose, and sucrose, was evaluated for its ability to identify blood culture isolates of Staphylococcus epidermidis (SE). Using a heavy suspension of organism in Mueller-Hinton broth, 50 microL was pipetted onto each disk in wells of a flat-bottomed microtiter tray. The tray was covered, incubated in a moist chamber in non-CO2 at 35 degrees C, and examined after 5 and 24 hours. A color change of yellow or orange was positive; no color change (red) was negative. Expected reactions for SE were as follows: negative trehalose, mannitol, and xylose; positive, sucrose. On evaluation of 227 coagulase-negative staphylococci (CNS) at 5 and 24 hours, the panel had a sensitivity of 94 and 96%, specificity of 92 and 89%, predictive value of positive tests of 97 and 96%, and predictive value of negative tests of 84 and 87%. This panel offered an inexpensive and convenient method for differentiating SE from the other CNS in five hours.

Widespread dissemination of Pneumocystis carinii infection in a patient with acquired immune deficiency syndrome receiving long-term treatment with aerosolized pentamidine.

Patients with acquired immune deficiency syndrome (AIDS) may be infected with many opportunistic pathogens, the most common of which is Pneumocystis carinii. P. carinii infection typically presents as a subacute pneumonia. However, rare cases of localized, extrapulmonary, and disseminated disease have been described. Standard therapy for P. carinii is systemically administered trimethoprim-sulfamethoxazole or pentamidine. These agents, however, frequently are associated with serious adverse effects. More recently, aerosolized pentamidine has been proposed as an alternative treatment for those who cannot tolerate standard therapy and as primary and secondary prophylaxis. Inhaled pentamidine is effective, but it is not without hazards. The authors describe a patient with AIDS who received long-term treatment with aerosolized pentamidine and yet died as a result of widely disseminated P. carinii infection.

Disseminated Trichosporon beigelii infection after orthotopic liver transplantation.

A 25-year-old male, who received an orthotopic liver transplant for fulminant hepatic failure resulting from hepatitis B, had disseminated Trichosporon beigelii infection develop. Of the 55 cases of disseminated T. beigelii that have been reported in the English-language medical literature, most have occurred in patients who were both neutropenic and had compromised cell-mediated immunity. Mortality has ranged from 60 to 78%. Outcome appears to depend significantly on leukocyte recovery. Histologically, Trichosporon can be confused with Candida; however, recognition of the arthroconidia and pleomorphic hyphae and pseudohyphae of Trichosporon should allow their differentiation.

Clinical comparison of the Baxter MicroScan Yeast Identification Panel and the Vitek Yeast Biochemical Card.

To determine the reliability of the Baxter MicroScan Yeast Identification Panel, processed by the Walkaway-96, and the Vitek Yeast Biochemical Card, 150 clinical yeast isolates (30 Candida albicans, 67 Candida species, not albicans, 26 Torulopsis glabrata, 13 Cryptococcus neoformans, 4 Saccharomyces cerevisiae, 6 Trichosporon beigelii, 3 Rhodotorula species, and 1 Geotrichum species) were tested on both systems. Results were compared with those obtained by the API 20C and the appearance of yeast cells on cornmeal Tween-80 agar. After inoculation of each system, results were available in 4 hours with MicroScan panels, 24-48 hours with Vitek cards, and 72 hours with the API 20C strips. On initial testing, 101 (67%) and 128 (85%) isolates, respectively, were correctly identified by MicroScan and Vitek. After repeat testing, the number of correctly identified isolates increased to 123 (82%) by MicroScan and to 142 (95%) by Vitek. Yeasts most commonly misidentified were Candida tropicalis, T glabrata, and Candida parapsilosis by MicroScan and C tropicalis and T glabrata by Vitek.

Clinical and pathologic features of Mycobacterium fortuitum infections. An emerging pathogen in patients with AIDS.

The clinical and pathologic features of Mycobacterium fortuitum infection in 11 patients with AIDS were characterized. Nine patients had cervical lymphadenitis; 2 had disseminated infection. The infection occurred late in the course of AIDS, and the only laboratory abnormality seen in more than half of patients (7/11) was relative monocytosis. Absolute monocytosis also was seen in 4 of 11 patients. In both cytologic and histologic preparations, the inflammatory pattern was suppurative with necrosis or a mixed suppurative-granulomatous reaction. M fortuitum, a thin, branching bacillus, stained inconsistently in direct smear and histologic preparations. Staining was variable with Gram, auramine, Brown-Hopps, Gram-Weigert, Kinyoun, Ziehl-Neelsen, modified Kinyoun, and Fite stains. Organisms, when present, were always seen in areas of suppurative inflammation. Incorrect presumptive diagnosis, based on misinterpretation of clinical signs and symptoms or on erroneous identification of M fortuitum bacilli as Nocardia species, led to a delay in proper therapy for 7 of 11 patients. Definitive therapy after culture identification resulted in complete resolution of infection in all patients except 1.