Danazol therapy for cyclic thrombocytopenia.

Cyclic thrombocytopenia is a rare disease characterized by cyclic oscillations of platelet counts from very low to normal or higher. Severe hemorrhage may occur during the thrombocytopenic phase. To date, treatments for this disorder have been disappointing. Its pathophysiology is unknown. We report a successful outcome using danazol therapy. Prior to danazol treatment, the patient had a 7 year history of cyclic thrombocytopenia, refractory to glucocorticoids, splenectomy, azathioprine, vinca alkaloids, plasma infusions, and hormonal manipulation with Premarin-Provera. Her platelet counts were found to be oscillating in a 21 day cycle between 1 x 10(9)/L and 500 x 10(9)/L. Platelet-associated antibodies were positive and chromium-labeled platelet survival time was shortened. Following 2 months of danazol therapy, her platelet counts at the nadirs were significantly higher than at previous nadirs, and at no time thereafter dropped to the critically low values seen before danazol. Also at 2 months of danazol treatment, the patient reported amelioration of petechiae, and at 9 months it was completely cleared. However, platelet-associated IgG remained positive and platelet counts continued to oscillate, typically between 100 x 10(9)/L and 300 x 10(9)/L in the second year, but stabilized at 3 years, when platelet-associated IgG also disappeared. Danazol was discontinued after 3.5 years. The patient remains in unmaintained remission today, approximately 5 years after discontinuance of danazol. It can be argued that the long-term outcome was due to spontaneous remission. However, significant improvement was noted from the outset of danazol therapy, and further improvement with long-term therapy, as seen in the response of chronic ITP to danazol therapy. Danazol may offer lasting benefit in cyclic thrombocytopenia.

Long-term danazol therapy in autoimmune thrombocytopenia: unmaintained remission and age-dependent response in women.

STUDY OBJECTIVE: To assess the long-term benefit and side effects of danazol therapy, and to delineate factors influencing the responses in patients with autoimmune thrombocytopenia. DESIGN: Before and after trial. SETTING: Referral-based hematology clinics and the University of Miami teaching hospitals. PATIENTS: Data were collected on 96 patients (60 women and 36 men, 45 of whom had had splenectomies) receiving danazol therapy for autoimmune thrombocytopenia and analyzed. INTERVENTION: Danazol was added to the previous therapy or begun as an initial therapy. Glucocorticoids were tapered gradually. MEASUREMENTS AND MAIN RESULTS: The overall response rate to danazol was 61.4%. Among responders, the platelet counts (mean +/- SD) before and after danazol treatment were 36 +/- 24 x 10(9)/L and 145 +/- 77 x 10(9)/L, respectively, and the time to response was 2.7 +/- 3 months. Sex, age, and the status of the spleen (absent or present) influenced the responses to danazol. In women, but not in men, response rates improved with advancing age, especially in the nonsplenectomized women. This may be because estrogen levels are high in younger women and low in older women and men. Danazol, when given longer than a year, induced remissions lasting for years even after its discontinuation, but early relapses were frequent when danazol was administered for less than 6 months. Platelet-associated IgG returned to normal range during unmaintained remission. CONCLUSION: Danazol is best suited for long-term medical management of autoimmune thrombocytopenia. It is well tolerated, and lasting, unmaintained remissions often occur after prolonged danazol administration. Age, sex, and the status of the spleen influence the responses. When danazol therapy is used, glucocorticoids can be substantially reduced in dosage or withdrawn. Danazol is a good alternative to splenectomy in elderly persons, especially in women.

Very low dose danazol in idiopathic thrombocytopenic purpura and its role as an immune modulator.

Danazol, an attenuated androgen, has been used successfully at its conventional dose (400-800 mg/day) in the treatment of idiopathic thrombocytopenic purpura (ITP). To minimize side effects, the authors tried a very low dose (50 mg/day) regimen which has not been used in any other disease and observed its efficacy in ITP. Fifteen patients were given this dosage of danazol. Its effects on T-cell subsets, B cells, and blastogenic response to pokeweed mitogen (PWM) and staphylococcus aureus (Staph A) were studied before and during therapy. The percentage of CD3 and the percentage and numbers of CD4 were significantly increased during therapy. Responses to PWM, a T-cell dependent B cell mitogen, were also significantly elevated during therapy. However, no change in the percentage of B (CD19) lymphocytes and response to Staph A, a polyclonal B cell mitogen, were noted. There were seven excellent-good and eight fair-poor responses in platelet counts. The excellent-good responders were found to have a more stable CD4 subset between before and during therapy compared to the fair-poor responders (p less than 0.05, Fisher's exact test). Very low dose danazol regimen, therefore, produced a significant increase in the CD4 without affecting the B cells. However, the excellent-good responder patients showed no significant increase in the CD4 lymphocytes.

Sex difference in the CD4 + CD45R+ T lymphocytes in normal individuals and its selective decrease in women with idiopathic thrombocytopenic purpura.

Chronic idiopathic thrombocytopenic purpura (ITP) is a well-defined autoimmune hematologic disorder. It is more common in women than men. We have shown that patients with active disease have abnormal T cell subsets which are more perturbed in women than in men and functional abnormalities that are confined to the T lymphocytes. In the current study, the anti-2H4 (CD45R) monoclonal antibody was used to divide the CD4 subset into their CD4+ CD45R+ and CD4+ CD45R- T lymphocytes. The subpopulations were measured in the peripheral blood of 26 women and 15 men with active ITP, 16 women and 8 men with disease in remission, and 33 normal healthy women and men. Normal women had increased percentages (P less than 0.0001) and numbers (P less than 0.005) of the CD4+ CD45R+ lymphocytes compared to normal men. Women with active disease had reduced percentages and numbers of CD4+ CD45R+ lymphocytes compared to normal women (P less than 0.0001) and women with disease in remission (P less than 0.001). Those women with decreased CD4+ CD45R+ lymphocytes had a significantly depressed lymphocyte response to polyclonal T cell mitogens. In contrast, men with active disease had neither such phenotypic changes nor functional correlations. The percentages and numbers of CD4+ CD45R- lymphocytes were not changed in either sex with active disease. In conclusion, women, but not men, with active ITP appear to possess a reduced subpopulation of CD4+ CD45R+ T lymphocytes.

Danazol therapy renders red cells resistant to osmotic lysis.

Danazol, an attenuated androgen, is useful in endometriosis, idiopathic thrombocytopenic purpura (ITP), and autoimmune hemolytic anemia (AIHA). However, its mechanism of action is unknown. We investigated the possibility that danazol affects cell membranes directly. Red cell osmotic fragility was studied in patients receiving danazol. A significant decrease in osmotic fragility was observed. Accompanying the change, peripheral blood smears showed many target cells and electron microscopy revealed extra folds in erythrocyte membranes. Twenty-two patients were studied prospectively before and after danazol. Osmotic fragility decreased significantly (P less than 0.001) in 1 month of therapy and progressed with further treatment. A rebound increase (P less than 0.01) was observed in 1 month after discontinuation of danazol among 16 patients. Incubation experiments showed that danazol-induced changes are not reversed with normal sera. Patient sera did not induce the changes in normal red cells. Danazol in vitro protected red cells from osmotic lysis at low concentrations but enhanced lysis at high concentrations. We suggest that danazol alters red cell membranes directly to increase their surface area, inducing target cell formation and increasing their resistance to osmotic lysis.

Depressed functional and phenotypic properties of T but not B lymphocytes in idiopathic thrombocytopenic purpura.

Chronic idiopathic thrombocytopenic purpura (ITP) is an autoimmune disorder in which the abnormality in cellular immunity has remained only vaguely defined. Previously we have shown that patients with ITP in its active phase have abnormal T cell subsets. We then examined the phenotypes of T and B lymphocytes in an additional 28 patients with ITP and 32 age- and sex-matched normal controls and compared the lymphocytes' capacity to respond to polyclonal T, T cell-dependent B, and B cell mitogens. Blastogenesis to optimal (5.0 micrograms/mL) and suboptimal (0.5 microgram/mL) concentrations of the polyclonal T cell mitogens were markedly depressed in patients compared with normal controls (P less than .0005). Similarly, a severe depression in response was noted with the polyclonal T cell-dependent B cell mitogen (P less than .000001). No difference was seen, however, with the polyclonal B cell mitogen. The proportions of pan-T and T helper/inducer lymphocytes were significantly depressed (P less than .005 and P less than .000005 respectively), and the T suppressor/cytotoxic lymphocytes increased (P less than .02) in patients relative to controls. But there was no difference in the proportion of B lymphocytes or in their functional response. The abnormal cellular immunity appears to be due to a defect in the T lymphocyte population without involvement of the B lymphocytes.

Low-dose danazol therapy in idiopathic thrombocytopenic purpura.

Although danazol is effective in the treatment of idiopathic thrombocytopenic purpura, its long-term safety and optimal dosage are not well established. We compared low (50 mg/d) and conventional (400 to 800 mg/d) dosages in 24 patients. Thirteen patients received the low dose 1 to 24 months after conventional doses had been discontinued (group 1). Five patients received low doses immediately after the conventional doses (group 2). Six patients were treated with low doses from the outset (group 3). In group 1, similar responses to either dose were seen in 9 patients, whereas there were better responses to conventional doses in 3 and to the lower dose in 1. All patients in group 2 maintained remissions with low doses. There were two excellent-good responses, one fair, and three poor responses in group 3. Side effects were generally less frequent and severe with the low doses. Low-dose danazol is better tolerated but took longer to obtain remissions, and is useful for maintenance therapy in the management of idiopathic thrombocytopenic purpura.

Immune modulation by danazol in autoimmune thrombocytopenia.

Danazol, an attenuated androgen, has recently been introduced into the treatment of autoimmune thrombocytopenia. We studied its effects on T helper/inducer (Thi) and T suppressor/cytotoxic (Tsc) lymphocytes in these patients. Prospectively nine patients were studied with their T-cell subsets measured before and during danazol therapy. Increases in the percentage of Thi lymphocytes (P less than 0.05) and Thi/Tsc ratios (P less than 0.001) were observed at 1 and 3 months of treatment. Retrospectively T-cell subset data on 30 patients not treated with danazol and 36 patients on danazol were compared with those of 35 normal controls. The group not on danazol had lower percentages of Pan T (P less than 0.05), Thi (P less than 0.002), and Thi/Tsc ratios (P less than 0.00005), and had higher percentages of Tsc lymphocytes (P less than 0.01), than those of controls. In the group treated with danazol the percentages of Pan T, Thi, and Tsc lymphocytes were similar to those of controls. The percentage of Thi in the treated group was higher (P less than 0.002) than in the untreated group. Thus, danazol appears to be an effective immune modulator, correcting the abnormality of T-cell subsets seen in autoimmune thrombocytopenia by increasing the percentage of Thi lymphocytes.

Differences in T cell subsets between men and women with idiopathic thrombocytopenic purpura.

Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disorder, occurring predominantly in women. We studied by flow cytofluorimetry the T cell subsets in men and women with ITP and compared them with healthy sex-matched volunteers. In healthy controls, women were found to have higher proportions of T helper/inducer (Th/i) and lower T suppressor/cytotoxic (Ts/c) lymphocytes and consequently higher Th/i:Ts/c ratios than men. Accordingly, in clinical surveys, patients and controls should be matched for sex for proper comparisons. In patients with ITP in its active phase, an imbalance in T cell subsets was found in both sexes. The perturbation was more severe in women who had a marked decrease in number and proportion of Th/i lymphocytes and an increase in the proportion of Ts/c lymphocytes, whereas in men only, the proportion of Th/i lymphocytes was decreased. When patients with active disease were compared to those with ITP in remission, the decrease in Th/i subsets still persisted in both sexes but the Ts/c subset in women had returned to normal proportions. Therefore, the immune imbalance in ITP is more marked in women than men; imbalances in both Th/i and Ts/c are present in women while Ts/c appears not to be involved in men.

Danazol therapy for autoimmune hemolytic anemia.

We evaluated the use of danazol in 15 patients with autoimmune hemolytic anemia of the warm antibody type. Danazol, 600 to 800 mg/d, was added to previous regimens or given initially in conjunction with high-dose prednisone treatment. Twelve patients with autoimmune hemolytic anemia associated with nonmalignant disorders or idiopathic autoimmune hemolytic anemia and 1 of 3 patients with underlying neoplasms showed a rise in hematocrit within 1 to 3 weeks. Thereafter, glucocorticoid doses were tapered to a minimum requirement or stopped. Once remission was sustained, the dose of danazol was reduced to 200 to 400 mg/d. Although levels of erythrocyte-bound IgG antibody and C3 decreased with therapy, only the decrease in C3 was statistically significant (p less than 0.05) in this limited study. Danazol was effective regardless of the severity of the disorder and success or failure of previous treatments. Danazol is valuable in the treatment of autoimmune hemolytic anemia and may be better suited than glucocorticoids for long-term management.

An animal model of alloimmune thrombocytopenia. I. The role of the mononuclear phagocytic system (MPS).

To understand better the role of the mononuclear phagocytic system (MPS) in accelerated destruction of donor platelets in man following repeated platelet transfusions, an experimental model has been developed using genetically defined animals. Brown Norway rats were immunized with Lewis platelets. Antibodies were detected by immunofluorescence microscopy, and their effects demonstrated by 111In-labeled platelet clearances in vivo and by measurements of organ radioactivity in sacrificed animals. All immunized rats developed platelet alloantibodies and showed a significant decrease (P less than 0.001) in donor platelet survival with sequestration in both the liver and spleen. Liver to spleen radioactivity ratios in nonimmunized animals were less than 0.1, whereas immunized animals had a ratio between 0.6 and 1.0, indicating relatively greater hepatic clearance of allogenic platelets. Studies currently in progress on the administration of vinca alkaloids to immunized animals suggest that the MPS can be impaired from clearing allogenic platelets. This model, therefore, should be helpful in studying the role of the MPS in platelet destruction.

Slow infusion of vinca alkaloids in the treatment of idiopathic thrombocytopenic purpura.

Vinca alkaloids are useful in the treatment of idiopathic thrombocytopenic purpura, a disorder in which macrophages remove platelets sensitized with antibody. Because vinca alkaloids avidly bind to platelets, drugs can be delivered selectively to macrophages. However, drugs given by bolus injection are cleared too rapidly to bind optimally to autologous platelets, and the use of allogeneic platelets loaded with drug in vitro is cumbersome, expensive, and dangerous. Therefore, slow infusions were devised to prolong the duration of enhanced plasma drug concentrations, thereby providing better conditions for in-vivo drug loading into autologous platelets. Twenty-four patients with refractory idiopathic thrombocytopenic purpura were given slow infusions; 17 had good to excellent responses. Eleven of eighteen patients who had been treated with bolus injections had better results when treated with slow infusions. Patients with improved responses had slower plasma clearance rates than did patients with poor responses. Slow infusion therapy had fewer side effects than bolus injection therapy. Slow infusions are the best method for long-term management.

Treatment of idiopathic thrombocytopenic purpura.

ITP is a common disease that is sorely in need of better management. Treatment strategy requires consideration of both long-term benefits and long-term hazards of each available therapeutic option. This discussion reviews conventional therapy as well as newer approaches to refractory ITP, including immunosuppressants, vinca alkaloids, colchicine, androgens, tamoxifen, and plasmapheresis.

Danazol for the treatment of idiopathic thrombocytopenic purpura.

Idiopathic thrombocytopenic purpura is an autoimmune disorder, most common in young women. We treated 22 patients with this disorder (12 of whom were women) with danazol, an androgen with reduced virilizing capability, for two months or longer. Fifteen had undergone splenectomy, all were receiving glucocorticoids, and 18 had also been given other treatments. Fifteen of the patients were benefited, 11 with sustained normalization of their platelet counts. Six of eight patients tested had initial increases in circulating platelet-reactive IgG; in all six there was a marked decrease concomitant with danazol therapy. Danazol was effective in both men and women, irrespective of previous treatments. The duration of remissions ranged from 2 to 13 months. The drug was well tolerated and appears to be better suited than glucocorticoids for long-term management of idiopathic thrombocytopenic purpura, but the exact indications for the use of danazol in this disorder remain to be determined.

Insulin immunogenicity in pregnancy: maternal and fetal studies.

Antibodies to insulin were found in 92% of the 138 insulin-treated pregnant diabetic patients studied. No effect of pregnancy was shown on insulin antibody levels. Higher insulin antibody levels were significantly associated with the previous use of conventional insulins. Change from conventional to highly purified porcine insulin during pregnancy produced a significant reduction in insulin antibody levels. The combination of protamine zinc and soluble insulin used before pregnancy was found to be the most immunogenic. Insulin antibodies were freely transferred to the fetus but not detectable after the first 8 months of life. No insulin antibodies were found in the cord blood or during the next few weeks in the infants of mothers who had no antibodies to their injected insulin. There was a tendency for higher insulin antibody levels to be associated with indices of neonatal morbidity but not with percentile birth weights and C-peptide levels in cord sera.