Tamoxifen therapy in steroid-resistant Riedels disease

Difficulties in investigating and treating fibrosing thyroid disorder (overlap of fibrosing variant of Hashimoto's thyroiditis and Riedel's thyroiditis)

A gentleman in his 90s presented with a slowly enlarging goitre over 18 months, causing manifestations of superior vena cava obstruction, dysphagia and hoarseness of voice. Investigations were suggestive of a fibrosing thyroid pathology. Surgical management was avoided due to high surgical risk. Treatment included prednisolone and tamoxifen with palliative management in the event of further medical deterioration. This article illustrates the difficulties in diagnosing and managing fibrosing thyroid diseases.

Effects of tamoxifen on the immune response phenotype in equine peripheral blood mononuclear cells

Tamoxifen (TAM) is widely utilized in the prevention and treatment of human breast cancer and has demonstrated the potential to modulate the immune response. It has been proposed as a therapeutic tool for immune-mediated diseases. TAM has been investigated as a possible treatment for asthma-like conditions in horses, revealing specific impacts on the innate immune system. While the effects of TAM on equine neutrophils are well-documented, its influence on lymphocytes and the modulation of the immune response polarization remains unclear. This in vitro study employed peripheral blood mononuclear cells (PBMC) from healthy horses, exposing them to varying concentrations of the TAM and assessing the expression of genes involved in the polarization of the immune response (TBX21, IFNG, GATA3, IL4, IL10, FOXP3, and CTLA4) in PBMC stimulated or not with PMA/ionomycin. Additionally, the effect of TAM over the proportion of regulatory T cells (Treg) was also assessed. TAM did not significantly affect the expression of these genes and Treg at low concentrations. However, at the highest concentration, there was an impact on the expression of GATA3, IL4, IL10, and CTLA4 genes. These alterations in genes associated with a Th2 and regulatory response coincided with a noteworthy increase in drug-associated cytotoxicity but only at concentrations far beyond those achieved in pharmacological therapy. These findings suggest that the effects of TAM, as described in preclinical studies on asthmatic horses, may not be attributed to the modification of the adaptive response.

Four Consecutive Cases of Peritoneal Dialysis-Related Encapsulating Peritoneal Sclerosis Treated Successfully with Tamoxifen

Sclerosing peritonitis is a rare complication of peritoneal dialysis (PD). In encapsulating peritoneal sclerosis (EPS), the most severe form of the disease, the intestine is entrapped in a fibrous tissue, causing intestinal obstruction. Patients are typically seriously ill, with evidence of infection and requirement for parenteral nutrition. A mortality rate of 73% has been reported. There is no established medical treatment and surgery has offered variable results.

Our unit provides renal replacement therapy for a population of about 2 million. The prevalent population of PD patients averages 110. The cumulative PD population since January 1993 is 643, with an EPS prevalence of 0.6%.

Influenced by the first case reported by Allaria in 1999 suggesting benefit of tamoxifen in treating EPS, we have treated with tamoxifen the four consecutive cases of EPS that have presented since 1999. All 4 patients have survived and recovered intestinal function. All showed prior evidence of peritoneal dysfunction with ultrafiltration failure and were characterized by long duration of PD therapy rather than multiple episodes of peritonitis.

We conclude that tamoxifen is a highly promising therapy in EPS, hitherto a usually fatal condition. This description of its efficacy in acutely ill patients with EPS complements its possible prophylactic use in patients with the earlier and milder disease, sclerosing peritonitis. A high index of clinical suspicion for sclerosing peritonitis is desirable, perhaps facilitated by routine screening of at-risk patients.

Tamoxifen as a new therapeutic tool for neutrophilic lung inflammation

BACKGROUND AND OBJECTIVE

Neutrophilic asthma is an important disease subgroup, including patients with severe phenotypes and erratic responses to standard treatments. Tamoxifen (TX), a selective estrogen receptor modulator (SERM) used as treatment of human breast cancer, has been shown to induce early apoptosis of equine blood and bronchoalveolar lavage fluid (BALF) neutrophils in vitro. Equine recurrent airway obstruction (RAO) is a naturally occurring neutrophilic condition, closely related with human asthma. Our purpose was to investigate the therapeutic potential of tamoxifen in horses with neutrophilic lung inflammation.

METHODS

Twelve horses underwent acute lung inflammation through exposure to allergens known to cause RAO, after which they received treatment with either tamoxifen or dexamethasone. Outcome measures included evaluation of clinical signs, BALF cytology, and early apoptosis of blood and BALF neutrophils.

RESULTS

Tamoxifen treatment decreased BALF neutrophil counts (65.3 ± 19.38% before treatment; 7.6 ± 4.5% 2 days post-treatment,; and 13.6 ± 9.3% 5 days post-treatment). A similar decrease was observed with dexamethasone treatment (48.6 ± 5.88% before treatment; 11.5 ± 8.1% 2 days post-treatment; 14.6 ± 10.3% 5 days post-treatment). Clinical and endoscopic scores improved in both treatment groups. Tamoxifen treatment significantly increased early apoptosis of peripheral blood neutrophils at 5 days post-treatment (27.04 ± 15.2%), and in BALF neutrophils at 2 and 5 days post-treatment (42.11 ± 11.67% and 48.98 ± 2.6%, respectively).

CONCLUSION

Tamoxifen treatment in horses with induced acute pulmonary inflammation promoted early apoptosis of blood and BALF neutrophils, reduction in BALF neutrophils and improvement in the animals' clinical status.

Comparison of the effects of captopril, tamoxifen and L-carnitine on renal structure and fibrosis after total unilateral ureteral obstruction in the rat

OBJECTIVE

To compare the effects of captopril, tamoxifen and L-carnitine on renal structure and the collagen content of the unilateral obstructed kidney in the rat using unbiased stereological methods.

MATERIAL AND METHODS

Rats (n=25) were assigned equally to one of five groups after ligation of the ureter: (i) normal controls (no hydronephrosis); (ii) positive controls (hydronephrotic rats without drug treatment); (iii) hydronephrotic rat with captopril treatment (CAP); (iv) hydronephrotic rats with L-carnitine treatment (L-CAR); and (v) hydronephrotic rats with tamoxifen treatment (TAM). Two weeks after unilateral ureteral obstruction the kidney was removed and histological sections were prepared. The kidney volume and the fractional volumes and absolute amounts of the cortex, medulla, tubules, renal corpuscles, vessels and fibrous tissue were determined using modern stereological techniques.

RESULTS

Kidney volume increased in the CAP group in comparison with the other groups. The absolute volume of the tubules was the same in the CAP group compared to the normal control group. However, in the other experimental groups, the amount of tubules decreased. The absolute volumes of the renal corpuscles and vessels did not show any significant differences between groups. The absolute volume of fibrous tissue showed significant increases in all groups in comparison with the normal controls. There were no differences in the absolute amounts of fibrous tissue between the positive control, CAP and L-CAR groups, but in the TAM group the collagen content was decreased.

CONCLUSIONS

Captopril preserved the amount of renal tubules and tamoxifen decreased fibrous tissue formation in unilateral obstructed kidneys but there were no differences in other hydronephrotic kidneys.

The complex role of estrogens in inflammation

There is still an unresolved paradox with respect to the immunomodulating role of estrogens. On one side, we recognize inhibition of bone resorption and suppression of inflammation in several animal models of chronic inflammatory diseases. On the other hand, we realize the immunosupportive role of estrogens in trauma/sepsis and the proinflammatory effects in some chronic autoimmune diseases in humans. This review examines possible causes for this paradox. This review delineates how the effects of estrogens are dependent on criteria such as: 1) the immune stimulus (foreign antigens or autoantigens) and subsequent antigen-specific immune responses (e.g., T cell inhibited by estrogens vs. activation of B cell); 2) the cell types involved during different phases of the disease; 3) the target organ with its specific microenvironment; 4) timing of 17beta-estradiol administration in relation to the disease course (and the reproductive status of a woman); 5) the concentration of estrogens; 6) the variability in expression of estrogen receptor alpha and beta depending on the microenvironment and the cell type; and 7) intracellular metabolism of estrogens leading to important biologically active metabolites with quite different anti- and proinflammatory function. Also mentioned are systemic supersystems such as the hypothalamic-pituitary-adrenal axis, the sensory nervous system, and the sympathetic nervous system and how they are influenced by estrogens. This review reinforces the concept that estrogens have antiinflammatory but also proinflammatory roles depending on above-mentioned criteria. It also explains that a uniform concept as to the action of estrogens cannot be found for all inflammatory diseases due to the enormous variable responses of immune and repair systems.

Uso do tamoxifeno no tratamento da tireoidite de Riedel: relato de um caso

O tratamento da tireoidite de Riedel (TR) consiste em cirurgia nos casos de fibrose local limitada. Na maioria dos casos, entretanto, necessita-se do uso de agentes antiinflamatórios, como os glicocorticóides ou, nos casos de falha ou recidiva, o tamoxifeno pode ser útil. Relatamos um caso de TR em uma mulher negra de 55 anos, associada a hipotireoidismo e hipoparatireoidismo. Avaliamos o tratamento com tamoxifeno na dose de 20mg duas vezes ao dia, durante onze meses. Após sessenta dias de tratamento, a paciente não relatava os sintomas compressivos antes apresentados. Entretanto, em um seguimento de onze meses, houve pouca melhora objetiva avaliada por ultrassonografia e tomografia seriados de região cervical. O tamoxifeno pode ser útil na TR, principalmente quando o uso do glicocorticóide é contra-indicado. A duração ideal do uso desta terapia não está definida.