1.
The role of functional thyroid capacity in pituitary thyroid feedback regulation.
Hoermann, R, Midgley, JEM, Larisch, R, Dietrich, JW
European journal of clinical investigation. 2018;(10):e13003
Abstract
BACKGROUND Thyroid feedback regulation and equilibria between thyroid hormones differ in the presence or absence of a functioning thyroid remnant. MATERIALS AND METHODS This study examines the relationship between the sensitivity of TSH feedback and thyroid capacity in untreated patients with thyroid autoimmune disease (n = 86) and healthy controls (n = 271). Functional capacity was estimated at maximum TSH stimulation, and pituitary TSH response was FT4-standardised with two established indices, the TSH index and the thyrotroph thyroid hormone resistance index. RESULTS The two indices correlated inversely with thyroid volume and functional thyroid capacity. Relationships were shifted upwards in patients with thyroid autoimmune disease. This positioned patients with thyroid autoimmune disease predominantly at the lower capacity range and upper part of TSH index. The relationship was modulated by serum FT3 concentrations, shifting 0.19 [95%CI: 0.12, 0.26] mIU/L per pmol FT3 increase. FT3 correlated with TSH index in total group ( τ = 0.09, P = 0.009) and both subgroups. FT3 levels were maintained despite a substantial capacity loss by progressively increasing conversion rates of T3 from T4, only collapsing at capacities below <1.5 pmol/s. CONCLUSION Functional thyroid capacity and preferential T3 generation are essential elements in adjusting the sensitivity of hypothalamic-pituitary-thyroid feedback control and balancing system equilibria. This suggests that the indirect regulatory role of glandular T3 co-secretion exceeds its quantitative contribution to the thyroid hormone pool. Implications for clinical practice extend to the diagnostic use of TSH in patients with impaired thyroid reserve.
2.
[Mycophenol acid in ocular automimmune disorders--can we optimise this therapy?].
Pleyer, U, Ruokonen, P, Schmidt, N, Feist, E, Höhne, M, Stanojlovic, S
Klinische Monatsblatter fur Augenheilkunde. 2008;(1):66-9
Abstract
BACKGROUND Mycophenolate mofetil (MMF) has gained acceptance as an immune modulatory agent in the treatment of autoimmune disorders such as uveitis. It represented a major advance, although optimal use may be limited, in particular, by gastrointestinal (GI) side effects in up to 50 % patients. This prospective study was undertaken to evaluate the effect of conversion from mycophenolate mofetil (MMF) to an enteric-coated mycophenolate sodium (EC-MPS). PATIENTS AND METHODS Within a cohort of 143 patients treated with MMF we prospectively followed 19 individuals who developed gastrointestinal side effects. Because of limited treatment alternatives, conversion to an enteric-coated mycophenolate sodium (EC-MPS) was undertaken. A standardised questionnaire (GSRS) was completed by each patient regarding GI adverse events, at predefined intervals during the study. RESULTS The spectrum of underlying disorders included uveitis (n = 16) and ocular cicatricial pemphigoid (n = 3) that were initially treated with MMF (1000 mg BID). All patients could be kept on EC-MPS treatment and followed with a mean follow-up of 44 weeks (median +/- 12). The maximum of scores on GSRS was reached at baseline (conversion to EC-MPS) in all but 3 patients. However, GSRS scores improved significantly between baseline and visit 4 (3 months) and remained stable further on (p < 0.03). In all but one (uveitis) patient the underlying disorders were under control demonstrating the similar efficacies of MMF and EC-MPS treatments. CONCLUSION The use of EC-MPS appears to be a valid treatment option in ocular autoimmune disorders. In particular. patients with gastrointestinal problems may profit from a significantly reduced frequency of adverse events.
3.
Normal renal function 8 to 13 years after cyclosporin A therapy in 285 diabetic patients.
Assan, R, Blanchet, F, Feutren, G, Timsit, J, Larger, E, Boitard, C, Amiel, C, Bach, JF
Diabetes/metabolism research and reviews. 2002;(6):464-72
Abstract
BACKGROUND Cyclosporin A (CyA) may induce acute nephrotoxicity. The question has been raised of the possible long-term unfavorable course of CyA-induced lesions. Advantage was taken of a large cohort of diabetic patients treated for several months using moderate CyA dosage to evaluate the long-term evolution of renal function in such patients. METHODS Two hundred and eighty five recently diagnosed type 1 diabetic patients having received CyA for a mean of 19.9 months were monitored for 13 years, in parallel with 100 similar patients treated with insulin alone. RESULTS In the CyA-treated group, a transient increase in creatininemia levels occurred during the first 18 months of treatment associated with a transient increase in renal vascular resistance. Both effects disappeared later on: creatininemia levels then remained normal. Inulin and p-aminohippurate (PAH) clearances remained normal throughout follow-up. Neither permanent renal failure nor progressive deterioration of renal function occurred in either group or in individual patients. A 10 to 12% increase in inulin and PAH clearance was elicited by IV amino acid infusion at 7 to 10 years, a finding consistent with a normal renal functional reserve. Patients with moderate kidney lesions on biopsy at 1 year had normal and stable clearance values at 7 to 13 years. The prevalence of arterial hypertension and retinopathy was lower in the CyA-treated group than in the control group, possibly because of the tighter metabolic control obtained in the CyA group. CONCLUSION These results suggest that low-dose CyA treatment combined with thorough monitoring does not result in long-term renal dysfunction.