Isolation and characterization of factor IX Chapel Hill: comparison to normal human factor IX

A classification scheme for patients with hemophilia B has been devised. Assessment of factor IX antigen and factor IX coagulant activity has confirmed the genetic heterogeneity of hemophilia B and has shown that some affected patients have normal amounts of factor IX-like protein. An abnormal factor IX, factor IX Chapel Hill, has been isolated from one of these variants and compared structurally and functionally to the purified normal human factor IX molecule. The major difference between factor IX Chapel Hill and normal human factor IX appears to be defective activation of the abnormal molecule by factor XIa and calcium.

Intravenous immunoglobulin products contain neutralizing antibodies to vaccinia

BACKGROUND AND OBJECTIVES

Individuals with primary or secondary immune-deficiency diseases may be at risk for vaccinia infection if widespread smallpox-immunization programmes are implemented in the United States of America (USA) for bioterrorism preparedness. The objective of this study was to determine whether commercial immune globulin (intravenous, human) products contain biologically active antibodies to vaccinia that have the potential to protect people, with immune deficiencies, from complications of vaccinia.

MATERIALS AND METHODS

Eight currently United States (US)-licensed and two European intravenous immunoglobulin (IVIG) products were tested in a vaccinia plaque-reduction neutralization assay. The in vivo activity of five of these lots was assessed in severely immune-deficient mice.

RESULTS

All tested products contained neutralizing anti-vaccinia activity, in vitro and in vivo.

CONCLUSIONS

The use of IVIG by individuals with inherited or acquired humoral immune deficiencies may provide some protection if they are inadvertently exposed to vaccinia.

Pasteurized, monoclonal antibody factor VIII concentrate: establishing a new standard for purity and viral safety of plasma-derived concentrates

A factor VIII concentrate (Monoclate-P) manufactured using a combination of pasteurization and immunoaffinity chromatography has been chosen to compare and contrast manufacturing aspects of plasma-derived factor VIII concentrates. Pasteurization is a virucidal method with a long safety record in clinical practice, while immuno-affinity chromatography selectively isolates and purifies the procoagulant protein of factor VIII, and partitions potential viral contaminants and nonessential proteins to the unbound fraction. The complete Monoclate-P production process reduces human immunodeficiency virus by > or = 10.5 log10, Sindbis (a model for hepatitis C virus) by > or = 6.5 log10, and murine encephalomyocarditis virus (a non-enveloped model virus) by 7.1 log10. The viral safety of Monoclate-P has been further demonstrated in clinical studies in patients not previously treated with blood or plasma-derived products. Additionally, the manufacture of Monoclate-P includes careful donor screening and plasma testing for antibodies to syphilis and human immunodeficiency, hepatitis B, and hepatitis C viruses to enhance source plasma safety. Combined with donor selection and plasma testing, multiple viral reduction steps effectively eliminate both lipid-enveloped viruses (e.g. human immunodeficiency, hepatitis B and C) and non-lipid-enveloped viruses (e.g. hepatitis A). In addition, polymerase chain reaction-based nucleic acid detection tests for hepatitis B and C viruses and for human immunodeficiency virus-1 have been introduced as part of an investigational new drug mechanism.

A new industrial order for physicians: a talk with Jeff C. Goldsmith, PhD. Interview by Richard L. Reece

Richard L. Reece, MD, interviewed Jeff C. Goldsmith, PhD, President of Health Futures, Inc. on October 12, 1999 to discuss how the Internet will affect health care delivery in the millennium. One of the most profound changes that he sees is how the relationship between physicians and patients will be altered. Empowered consumers are where the real revolution is happening--a trend sometimes overlooked by physicians. Goldsmith says, "The key thing physicians have missed is that the patient is in charge of the process.... The Internet has enabled patients to aggregate their collective experience across disease entities." But there is too much information. "It is almost universally acknowledged by patients and physicians that there is a terrible quality problem. Getting from information to knowledge is a huge commercial opportunity for somebody." He doesn't think that people have put enough emphasis on the collective learning part of this new technology.

Succeeding beyond the Year 2000: how to rise to the challenges of the new millennium. Interview by Jill L. Sherer

Are you ready to take your organization into the 21st century? Do you fully grasp the implications of current and emerging trends in the field? Healthcare Executive talked with six healthcare experts and asked them what they saw as the greatest challenge for both executives and their organizations in the new millennium. Although the experts' opinions vary, their responses emphasize the importance of repairing old relationships and building new partnerships between those working in healthcare organizations, as well as bringing a consumer focus back to healthcare delivery.

Serum and cerebrospinal fluid pharmacokinetics of intravenous and oral lamivudine in human immunodeficiency virus-infected children

We studied the pharmacokinetics of intravenously and orally administered lamivudine at six dose levels ranging from 0.5 to 10 mg/kg of body weight in 52 children with human immunodeficiency virus infection. A two-compartment model with first-order elimination from the central compartment was simultaneously fitted to the serum drug concentration-time data obtained after intravenous and oral administration. The maximal concentration at the end of the 1-h intravenous infusion and the area under the concentration-time curve after oral and intravenous administration increased proportionally with the dose. The mean clearance of lamivudine (+/- standard deviation) in the children was 0.53 +/- 0.19 liter/kg/h (229 +/- 77 ml/min/m2 of body surface area), and the mean half-lives at the distribution and elimination phases were 0.23 +/- 0.18 and 2.2 +/- 2.1 h, respectively. Clearance was age dependent when normalized to body weight but age independent when normalized to body surface area. Lamivudine was rapidly absorbed after oral administration, and 66% +/- 25% of the oral dose was absorbed. Serum lamivudine concentrations were maintained above 1 microM for >/=8 h of 24 h on the twice daily oral dosing schedule with doses of >/=2 mg/kg. The cerebrospinal fluid drug concentration measured 2 to 4 h after the dose was 12% (range, 0 to 46%) of the simultaneously measured serum drug concentration. A limited-sampling strategy was developed to estimate the area under the concentration-time curve for concentrations in serum at 2 and 6 h.

Managed care mythology: supply-side dreams die hard

As managed care gains increasing influence over the American health financing system, economic pressures and emerging market realities have created a fertile climate for wishful thinking on the part of hospital executives and physicians. Rather than accept the inevitability of reducing excess capacity and incomes, providers cling to self-serving myths about managed care's strategic direction. Here are five of these myths along with their contrasting market realities.

Rationale and indications for continuous infusion of antihemophilic factor (factor VIII)

The continuous infusion of drugs and biological compounds, such as factor VIII concentrate, should enhance therapeutic efficacy. Factor VIII can be produced by recombinant DNA technology or derived from plasma. Improvements to the stability of the compound have made continuous infusion feasible. Current and potential applications of continuous infusion of factor VIII product include (1) peri-operative conditions, (2) bleeding that threatens life or limb, (3) primary or secondary Prophylaxis and (4) immune tolerance therapy for factor VIII allo-antibodies. Less use of costly factor VIII and decreased laboratory expenses also contribute to the usefulness of continuous infusion.

Acquired protein S deficiency in children infected with human immunodeficiency virus

OBJECTIVES

To determine the prevalence of an acquired deficiency of protein S, a coagulation inhibitor, in children infected with the human immunodeficiency virus (HIV) and to identify clinical and laboratory features associated with this coagulation abnormality.

METHODS

A convenience sample of HIV-infected children, ages 2 to 18 years, was evaluated for total, free and functional protein S; total and functional protein C; prothrombin and activated partial thromboplastin times; fibrinogen; antithrombin III activity; dilute Russell viper venom time; IgG anticardiolipin antibodies; von Willebrand factor antigen; C4b-binding protein; CD4+ T lymphocyte counts; HIV p24 antigen concentration; and serum beta 2-microglobulin concentrations.

RESULTS

Thirty-four subjects were evaluated. Twenty-four subjects were infected perinatally and 10 by transfusion. Nine of the subjects were CDC Class N (asymptomatic), 13 were Class A/B (symptomatic without AIDS-defining condition) and 12 were Class C (AIDS). None had previously documented thrombosis, nephrosis or significant hepatic dysfunction. Twenty-six subjects (76.5%) had decreased free protein S, and 19 (55.9%) had functional protein S < 2 SD below the mean of laboratory controls. Decreased functional protein S was seen in 33.3% of Class N, 53.8% of Class A/B and 75.0% of Class C subjects. The prevalence of decreased total and functional protein S was greater in those with absolute CD4+ T lymphocyte counts < 200/mm3 compared to those with CD4+ counts > or = 200/mm3 (75.0% vs. 38.9%; chi square, 4.48, P = 0.034). A trend toward negative correlation was observed between protein S and duration of HIV infection only for Class N subjects. No linear correlation was seen between protein S and CD4+ T lymphocyte counts; and no significant relationships were observed between protein S values and CMV status, HIV p24 antigen, C4b-binding protein, von Willebrand factor antigen, IgG anti-cardiolipin antibodies or serum beta 2-microglobulin values.

CONCLUSIONS

Acquired protein S deficiency is common in HIV-infected children. The high prevalence of this anticoagulant abnormality suggests an increased risk for thrombotic complications in this population.

A phase I/II evaluation of stavudine (d4T) in children with human immunodeficiency virus infection

OBJECTIVES

To determine the pharmacokinetic properties, tolerance, safety, and preliminary activity of stavudine in human immunodeficiency virus (HIV)-infected children.

DESIGN

Phase I/II, open and dose-ranging (0.125 to 4 mg/kg/day in two divided doses).

PATIENTS

Thirty-seven HIV-infected children (median age, 5.5 years; range, 7 months to 15 years) with a median CD4+ lymphocyte count at baseline of 242 cells/microL (range 2 to 2290 cells/microL). Thirty children had symptomatic HIV disease at entry; seven had HIV-related immunosuppression alone. Twenty-nine subjects had a history of prior zidovudine (ZDV) therapy.

RESULTS

As compared with adults receiving the same weight-adjusted doses, the children we studied had lower maximum observed stavudine plasma concentrations (CMAX) and area under the plasma concentration versus time curves (AUC), and more rapid stavudine elimination. The absolute oral bioavailability of the drug ranged from 61% to 78%. There was no plasma accumulation of the drug between day 1 and week 12. Week 12 cerebrospinal fluid stavudine concentrations in seven subjects, obtained approximately 2 to 3 hours after oral doses, ranged from 16% to 97% of concomitant plasma concentrations. Stavudine was well-tolerated and there were no dose-related clinical or laboratory adverse events. One subject with baseline neurologic abnormalities experienced a transient episode of apparent pain or discomfort in her fingers, possibly related to stavudine. All other adverse events were attributed to underlying disease. Stavudine activity, measured indirectly by CD4+ lymphocyte count and serum p24 antigen concentration changes, was observed in some subjects. Progression of HIV disease and survival correlated with prior ZDV therapy, HIV disease classification, baseline CD4+ lymphocyte count, and weight growth velocity.

CONCLUSIONS

Stavudine appears to hold promise for the treatment of HIV infection in children. Its pharmacokinetic properties are consistent and predictable, and it appears to be remarkably well-tolerated and safe. Although our study was not designed to assess the drug's efficacy, preliminary clinical and laboratory evidence of activity was observed.

Combination and monotherapy with zidovudine and zalcitabine in patients with advanced HIV disease. The NIAID AIDS Clinical Trials Group

OBJECTIVE

To compare the safety and efficacy of continuing zidovudine therapy with that of zalcitabine alone or zalcitabine and zidovudine used together.

DESIGN

A randomized, double-blind, controlled trial.

SETTING

AIDS Clinical Trials units and National Hemophilia Foundation sites.

PATIENTS

1001 patients with symptomatic human immunodeficiency (HIV) disease and 300 or fewer CD4 cells/mm3 or asymptomatic HIV disease and 200 or fewer CD4 cells/mm3 who had tolerated zidovudine therapy for 6 months or more.

INTERVENTION

Patients were randomly assigned to receive zidovudine, 600 mg/d; zalcitabine, 2.25 mg/d; or zidovudine, 600 mg/d, and zalcitabine, 2.25 mg/d.

MEASUREMENTS

The primary end point was time to disease progression or death.

RESULTS

The median follow-up time was 17.7 months. The estimated 12-month event-free rates were 70%, 67%, and 73%, respectively, for the zidovudine, zalcitabine, and combination groups (P = 0.26). A trend analysis showed significantly lower progression rates for combination therapy compared with zidovudine therapy as the pretreatment CD4 cell count increased (P = 0.027). For patients with 150 or more CD4 cells/mm3, those receiving combination therapy were less likely to have disease progression or to die than were those receiving zidovudine (relative risk, 0.51; 95% CI, 0.28 to 0.93; P = 0.029). We observed no difference between the zalcitabine and zidovudine groups (relative risk, 0.74; CI, 0.40 to 1.36; P = 0.33). For patients with 50 to 150 CD4 cells/mm3 or fewer than 50 CD4 cells/mm3, we found no differences among the treatment groups (P = 0.69 and P = 0.57, respectively). Severe toxic effects occurred less frequently among patients with 150 or more CD4 cells/mm3.

CONCLUSIONS

We found no overall benefits of zalcitabine used alone or with zidovudine. However, a trend analysis suggested a better outcome for combination therapy compared with zidovudine as the pretreatment CD4 cell count increased.

Zidovudine and didanosine combination therapy in children with human immunodeficiency virus infection

OBJECTIVE

Zidovudine and didanosine are both beneficial for the treatment of human immunodeficiency virus (HIV) infection in children. Because disease progression and toxicity often limit their long-term use as single agents, new approaches to using nucleoside analogues are necessary to improve current antiretroviral therapy.

DESIGN

We conducted a phase I-II study to evaluate the tolerance, pharmacokinetics, and antiviral activity of the combination of zidovudine and didanosine in children with HIV infection. Sixty-eight children who were either previously untreated or who had manifested hematologic toxicity on full-dose zidovudine were enrolled. Eight dose combinations were studied in the previously untreated children, with doses of zidovudine ranging from 90 to 180 mg/m2 every 6 hours and doses of didanosine ranging from 90 to 180 mg/m2 every 12 hours.

RESULTS

Fifty-four previously untreated HIV-infected children were enrolled in this part of the study, of whom 49 remained in the study for a minimum of 24 weeks. For children with previous zidovudine-related hematologic toxicity, three dose levels with zidovudine at 60 mg/m2 every 6 hours orally and didanosine ranging from 90 to 180 mg/m2 every 12 hours orally were used. A total of 14 children were enrolled in this part of the study, and 12 remained on therapy for at least 24 weeks. No evidence of new or enhanced toxicity was observed in either group. After 24 weeks, the median CD4 cell count for all patients increased from 331 to 556 cells/mm3 (P = .01). For the previously untreated group, the median increase in CD4 counts was from 386 to 726 cells/mm3 (P = .003). The median p24 antigen concentration (in those with a detectable level at baseline) decreased from 95 to < 31 pg/mL (p < .001). The geometric mean titer of HIV in plasma decreased from 83.1 to 2.7 tissue culture infectious doses/mL (P = .001).

CONCLUSIONS

The combination of zidovudine and didanosine was well-tolerated at doses as high as those used in single agent therapy. Potent in vivo antiviral activity was observed. Combination therapy with nucleoside analogues may be an important approach to optimizing the use of these agents in the treatment of HIV infection.

Continuous infusion of monoclonal antibody-purified factor VIII: rational approach to serious hemorrhage in patients with allo-/autoantibodies to factor VIII

Hemorrhage in a patient with factor VIII inhibitor is associated with increased morbidity and mortality. Treatment with factor IX complex concentrates or recombinant factor VIIa (rVIIa) may not control bleeding and may induce thrombosis. In this study, continuous infusion of a monoclonal antibody-purified factor VIII [correction of factor VII] concentrate (Monoclate-P) was used successfully in two hemophilic patients with factor VIII alloantibodies and one nonhemophilic patient with a factor VIII autoantibody. In two patients, hemorrhage was life-threatening, and, in one, bleeding did not stop with repeated infusions of activated factor IX complex concentrates. The patients' ages ranged from 4 to 15 years, and the inhibitor levels from 6 to 300 Bethesda units/ml. Clinical hemostasis was excellent, and in vivo recovery of infused factor VIII was achieved. When an excess of monoclonal factor VIII was added to the inhibitor plasma in vitro, a stable level of residual factor VIII activity was noted after an initial rapid loss. This second-order reaction occurs in plasmas of patients with type I factor VIII inhibitors. In one patient, we showed that the saturation dose of the factor VIII inhibitor predicted in vivo recovery of factor VIII:C. These data emphasize the importance of characterizing the kinetic reactions of the factor VIII inhibitor. Furthermore, we confirm previous reports that continuous infusion of monoclonal factor VIII is a safe and effective treatment of patients with factor VIII inhibitors in whom hemorrhage is either life-threatening or refractory to standard treatment.

Building integrated systems--driving the nitroglycerin truck

Both sides of the bizarre, sadomasochistic relationship between physicians and hospitals bring baggage to the "arranged marriage" of the integrated healthcare system.

Lingual hemorrhage in a patient with hemophilia A complicated by a high titer inhibitor. Management by continuous infusion of monoclonal antibody-purified factor VIII

PURPOSE

The management of oral bleeding in hemophilia A patients with high titer inhibitors can be challenging. Simultaneous administration of activated prothrombin complex concentrates and antifibrinolytic agents is potentially dangerous because both agents have thrombogenic properties. We report sustained control of life-threatening lingual hemorrhage in a hemophilic patient with a high titer inhibitor (100 Bethesda Units/ml) on continuous infusion of a monoclonal antibody-purified factor VIII concentrate (75 U/kg/h).

METHODS AND RESULTS

In vivo hemostasis was achieved without an initial increment in free plasma factor VIII:C. The biphasic nature of recovered factor VIII:C indicated initial antigen-antibody formation, a saturation point, then a rapid rise of free factor VIII in plasma. In vitro, rapid loss of factor VIII activity was noted in mixtures of patient's plasma and purified factor VIII during incubation at 37 degrees C. When an excess of purified factor VIII was added to patient's plasma, a plateau of stable residual factor VIII activity followed the initial loss of factor VIII activity, suggesting a second-order reaction.

CONCLUSION

This type I kinetic response is typical of alloantibodies induced by exposure to factor VIII concentrates.

The reshaping of healthcare. Part 2

Powerful new tools produced by the biotechnology revolution--predictive genetics (and ultimately genetic therapy) and immunotherapy--will eventually make obsolete much of our current armada of crude "halfway" technologies, and enable us to prevent most illness altogether. These advances were discussed in the May/June issue of the Journal. This article addresses their likely impact on healthcare delivery.

Coagulation factor IX: successful surgical experience with a purified factor IX concentrate

The use of plasma-derived coagulation factor concentrates has been marked by the transmission of viral agents. Infusions of factor IX complex concentrates have been additionally complicated by inappropriate thrombosis. Use of these concentrates in the neonate, in those with liver disease, and in surgical patients results in increased risk for this complication. Twenty patients have been infused with a purified coagulation factor IX concentrate for fall-off and recovery studies. A two-compartment model indicated an initial phase half-life of 4.06 +/- 2.86 hr and a beta phase half-life of 20.0 +/- 3.8 hr following the administration of AlphaNine, Coagulation Factor IX (Human). In vivo recovery was 62.7% +/- 13.8%, with an average factor IX coagulant level of 73% +/- 16% at 15 min after the infusion of a mean dose of 45 U/kg. Thirteen previously transfused patients with hemophilia B underwent major orthopedic or general or dental surgery using this purified factor IX. Operative outcomes were excellent in all patients. No excessive bleeding was noted. There was no laboratory or clinical evidence for a disseminated intravascular coagulopathy. The excellent surgical outcomes observed in this multitransfused group with biochemical evidence for active liver disease demonstrates the utility and safety of a purified coagulation factor IX concentrate.

Atypical pulmonary diseases associated with AIDS

We present three patients with pulmonary diseases not usually associated with AIDS. Early recognition and treatment allowed a favorable outcome. The cases are discussed and the literature is reviewed.

Pneumocystis carinii pneumonia complicating multiple myeloma

Pneumocystis carinii pneumonia complicated the course of two patients with multiple myeloma. The diagnosis was established in both cases by bronchoalveolar lavage, which demonstrated the typical pneumocysts. Clinical and roentgenographic improvement in both patients was observed following a course of trimethoprim-sulfamethoxazole. One patient had lymphocyte subsets performed with a CD4/CD8 ratio of 0.8; both patients were HIV antibody-negative by ELISA. Both patients tolerated prophylactic TMP-SMX given concurrently with the subsequent chemotherapy for myeloma. We suggest that the immune defect seen in multiple myeloma may have placed these patients at risk for opportunistic infections such as P carinii pneumonia; however, as opposed to patients with AIDS, our patients tolerated therapy with TMP-SMZ quite well.

Endoscopy in the diagnosis of gastrointestinal Mycobacterium avium-intracellulare infection

Two cases of mycobacterium avium-intracellulare (MAI) infection in association with acquired immunodeficiency syndrome (AIDS) are presented to highlight the distinctive upper gastrointestinal endoscopic appearances: 2 X 4 mm diameter, white nodules with intervening erythema and hemorrhagic erosions covered the mucosa of the second part of the duodenum. Histological evaluation of these nodules revealed diffuse expansion of the lamina propria by macrophages that contained numerous intracellular and extracellular acid-fast organisms. We conclude that endoscopy with endoscopic biopsy may represent the most rapid and sensitive diagnostic tool available in this disease.

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.

Hickman catheter-induced thoracic vein thrombosis. Frequency and long-term sequelae in patients receiving high-dose chemotherapy and marrow transplantation

One hundred sixty-eight bone marrow transplant recipients and 49 patients who received high-dose chemotherapy were evaluated for symptomatic thrombosis after Hickman catheter placement. The timing of thrombotic complications was different between these two groups, with the transplant group having a significantly lower thrombus-free survival by 28 days after catheter placement. By 100 days after placement the thrombus-free survival rates of the two groups were similar. The platelet count at time of catheter placement was significantly lower in the nontransplant group, and the thrombus-free survival was longer in patients whose catheter was placed when their platelet count was less than 150,000, suggesting that thrombocytopenia delays thrombotic complications. Placement of two Hickman catheters resulted in a 12.9% thrombosis rate (21 of 162 patients) and was significantly more likely to be associated with thrombosis than placement of one catheter. Long-term follow-up evaluation of patients treated without successful fibrinolytic therapy showed no residual symptoms of venous obstruction. In those patients presenting with concomitant catheter obstruction resulting from thrombosis, low-dose fibrinolytic therapy was successful in restoring catheter function 70% of the time. Placement of two Hickman catheters is associated with an inordinate incidence of thrombosis. Thrombocytopenia at the time of catheter placement may delay this complication. Thrombotic catheter obstruction can be treated successfully with low-dose fibrinolytic therapy. Even without fibrinolytic therapy, catheter-induced subclavian vein thrombosis rarely causes long-term disability.

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.

The use of purified clotting factor concentrates in hemophilia. Influence of viral safety, cost, and supply on therapy

Treatment of hemophilia, although greatly improved in recent years, continues to be problematic owing to infectious complications of blood product replacement therapy. This report examines the therapeutic options presently available for the treatment of hemophilia, focusing on the potential for repeated viral exposure to influence the progression of infectious disease, decreased risks of viral transmission with blood products produced using newer viral inactivation procedures, higher economic costs of newer blood products, and the current inadequate supply of blood products in the United States.

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.

Abnormal fibrinolysis in healthy male cigarette smokers: role of plasminogen activator inhibitors

The extrinsic fibrinolytic system and its response to cigarette smoking was studied in five healthy male smokers 35-45 years old. Tissue plasminogen activator (t-PA) release in response to venous occlusion was intact both at 8:00 A.M. and 3:00 P.M. Acutely smoking two cigarettes neither stimulated fibrinolysis nor changed levels of t-PA or plasminogen activator inhibitors. Functional plasminogen activator inhibitor (PA-I) levels and euglobulin lysis times were higher in the smoking group than in a control group matched for age, sex, and body mass. Antigenic levels of PA-I 1, the PA-I derived from vascular endothelial cells and platelets, were similar in both groups. While smoking did not acutely alter fibrinolysis in chronic smokers, these individuals had a high frequency of abnormal fibrinolysis characterized by high levels of PA-I activity. This abnormality is due to either high specific activity of PA-I 1 or to the presence of other antigenically distinct plasminogen activator inhibitors. Abnormal fibrinolysis may be one mechanism contributing to the thrombotic diathesis of cigarette smokers.

Reversible agranulocytosis related to azidothymidine therapy

Hematopoietic toxicity from Zidovudine (AZT) is fairly common, resulting in a requirement for red cell transfusions in up to 25% of patients. Reversible agranulocytosis occurred following approximately 1 week of AZT therapy in a man with AIDS. He recovered from the episode without incident. There was no evidence for underlying bone marrow dysfunction or an adverse drug reaction. Careful monitoring of AZT therapy continues to be of great importance.

Pulmonary emboli in patients receiving chemotherapy for non-Hodgkin's lymphoma

Combination chemotherapy has dramatically improved the prognosis of patients with intermediate and high grade histologic subtypes of non-Hodgkin's lymphomas. Treatment-related complications, however, are considerable, and a common problem encountered is respiratory distress or respiratory insufficiency. Usually these difficulties have been attributed to infectious etiologies or to chemotherapy-induced interstitial fibrosis, most often involving bleomycin. We describe five patients presenting with respiratory problems several weeks after the initiation of chemotherapy. These patients, who represent 3 percent of all patients treated with a single bleomycin-containing regimen for intermediate or high grade non-Hodgkin's lymphoma, were all initially thought to have chemotherapy-induced interstitial fibrosis but were found on subsequent evaluation to have pulmonary emboli. Of the three patients in whom pulmonary emboli were diagnosed antemortem, two had symptoms suggestive of pulmonary emboli and all were successfully treated and remained well and free of lymphoma for over 24 months. Two additional patients were diagnosed at autopsy. We suggest that pulmonary emboli may contribute significantly to the morbidity and mortality of patients undergoing chemotherapy for non-Hodgkin's lymphoma and recommend that patients presenting with respiratory difficulties be evaluated for pulmonary emboli.