Subclinical non-autoimmune hypothyroidism in children with steroid resistant nephrotic syndrome

Outcomes of children with idiopathic steroid resistant nephrotic syndrome: a single centre observational study

INTRODUCTION

Idiopathic steroid resistant nephrotic syndrome (SRNS) has variable outcomes in children. The primary objective of the present study was to assess the cumulative remission rate and the secondary objectives were to assess factors affecting the remission status, kidney function survival, and adverse effects of medications.

METHODS

One hundred fourteen patients with SRNS were included. Calcineurin inhibitor-based treatment protocol along with prednisolone and angiotensin-converting enzyme inhibitor were used, and patients were followed over 5 years.

RESULTS

Median age was 4.5 years; 53.5% of cases were between 1 to 5 years of age. Sixty-two patients (54.4%) were at initial stage and 52 (45.6%) were at a late SRNS stage. Median eGFRcr was 83.5 mL/min/1.73m2 at presentation. Of the 110 patients, 63 (57.3%) achieved remission [complete remission 30 (27.3%), partial remission 33 (30%)], and 47 (42.7%) had no remission. Kidney function survival was 87.3% and 14 cases (12.7%) had progression to CKD (G3-8, G4-3, G5-1, and G5D-2). Median duration of follow up was 36 months (IQR 24, 60). Age of onset, cyclosporine/tacrolimus, eGFRcr, and histopathology (MCD/FSGS) did not affect remission. Similarly, remission status in addition to age of onset, drug protocol, and histopathology did not significantly affect kidney function during a period of 5 years. Hypertension, cushingoid facies, short stature, cataract, and obesity were observed in 37.7, 29.8, 25.5, 17.5, and 0.7% of cases, respectively.

CONCLUSION

About half of the cases achieved remission. Age of onset of disease, cyclosporine/tacrolimus use, and histopathological lesion neither affected remission status nor short-term kidney function survival in SRNS.

Desfechos de crianças com síndrome nefrótica idiopática córtico-resistente: um estudo observacional de centro único

RESUMO Introdução: A síndrome nefrótica idiopática córtico-resistente (SNICR) apresenta desfechos variáveis em crianças. O objetivo principal deste estudo foi avaliar a taxa de remissão cumulativa. Os objetivos secundários foram avaliar fatores que afetam status de remissão, sobrevida da função renal e efeitos adversos de medicamentos. Métodos: Foram incluídos 114 pacientes com SNCR. Utilizou-se protocolo de tratamento baseado em inibidores de calcineurina juntamente com prednisolona e inibidor da enzima conversora de angiotensina. Os pacientes foram acompanhados durante 5 anos. Resultados: A idade mediana foi 4,5 anos; 53,5% dos casos tinham entre 1 e 5 anos. 62 pacientes (54,4%) estavam em estágio inicial; 52 (45,6%) em estágio tardio da SNCR. A TFGecr mediana foi 83,5 mL/min/1,73 m2 na apresentação. Dos 110 pacientes, 63 (57,3%) alcançaram remissão [remissão completa 30 (27,3%), remissão parcial 33 (30%)], e 47 (42,7%) não apresentaram remissão. A sobrevida da função renal foi 87,3%; 14 casos (12,7%) progrediram para DRC (G3-8, G4-3, G5-1, G5D-2). A duração mediana do acompanhamento foi 36 meses (IIQ 24, 60). Idade no início, ciclosporina/tacrolimus, TFGecr e histopatologia (DLM/GESF) não afetaram a remissão. Igualmente, status de remissão, além da idade no início, protocolo de medicamentos e histopatologia não afetaram significativamente a função renal por 5 anos. Observou-se hipertensão, fácies cushingoide, baixa estatura, catarata e obesidade em 37,7; 29,8; 25,5; 17,5; e 0,7% dos casos, respectivamente. Conclusão: Aproximadamente metade dos casos alcançou remissão. Idade no início, uso de ciclosporina/tacrolimus e lesão histopatológica não afetaram o status de remissão nem a sobrevida da função renal a curto prazo na SNICR.

Prevalence of hypothyroidism in Japanese chronic kidney disease patients

Background

Major symptoms of progressive chronic kidney disease (CKD) are similar to those of hypothyroidism. Hidden symptoms of hypothyroidism underlying CKD are often observed in clinical practice. This study aimed to ascertain the frequency of hypothyroidism complicated by CKD, and to analyze factors impacting thyroid function.

Methods

During the period from April 2012 through October 2016, 510 CKD patients at our outpatient clinic were measured thyroid and kidney function for diagnosing hypothyroidism (overt hypothyroidism, OH; subclinical hypothyroidism, SH; non-thyroidal illness, NTI) and evaluating the stage of CKD. All patients were over 15 years of age.

Results

There were significant differences in age, estimated glomerular filtration rate (eGFR), urinary protein (UP), and serum albumin (Alb) among patients with OH, SH, and NTI compared to the normal group in univariate and multivariate analyses. UP showed the highest odds ratio of OH, SH, and NTI but no differences were recognized in gender in each group. Frequency distribution showed that the prevalence of thyroid dysfunction was greater among more severe stage of CKD with higher amount of UP. OH and SH did not show high positive ratio of anti-thyroglobulin antibody (TgAb) and anti-thyroid peroxidase antibody (TPOAb). NTI and normal subjects showed higher positive ratio as 50.0% and 42.9% of TgAb and TPOAb than OH and SH.

Conclusions

Hypothyroidism complicated by CKD exhibited a high prevalence. Age, eGFR, UP, and serum Alb were related to the prevalence of hypothyroidism, whereas gender was not and this was contradicted to the prevalence of hypothyroidism in general population. The prevalence of OH and SH was higher among patients with higher stage of CKD with increased UP. Hypothyroidism complicated by CKD may involve different onset mechanisms unrelated to antithyroid antibodies (ATAb). In CKD patients, assessments of OH and SH, as well as NTI, are needed for proper diagnosis.

Severity of Proteinuria Is Directly Associated With Risk of Hypothyroidism in Adults

CONTEXT

Proteinuria can cause or exacerbate hypothyroidism, possibly due to urinary loss of protein-bound thyroid hormone. However, the precise relationship between proteinuria and hypothyroidism remains unclear.

OBJECTIVE

This work aimed to determine the prevalence of hypothyroidism in patients with proteinuria and the relationship between hypothyroidism and degree of proteinuria.

DESIGN

A retrospective cohort study was conducted from December 1979 to March 2015.

SETTING

This study was conducted at a large academic hospital.

PATIENTS

All paired samples of urine protein and serum thyrotropin (TSH), measured within 24 hours, were obtained from adults (age > 18 years) with at least one instance of urine protein greater than 0.2 g/day or mg/mg creatinine.

MAIN OUTCOME MEASURES

Samples were stratified by urine protein tertile. Mean TSH and risk of TSH elevation were compared among tertiles using analysis of covariance and generalized estimating equations controlled for age, sex, samples per patient, and levothyroxine treatment.

RESULTS

A total of 2676 samples were identified from 2136 patients. Mean ± SE TSH (mIU/L) was increased in the highest tertile of urine protein (> 1.75g/day) compared to the lower 2 tertiles (2.09 ± 0.07 vs 1.59 ± 0.07, 1.59 ± 0.06, P < .001). The highest tertile had a greater prevalence of TSH greater than 5 mIU/L (17.2% vs 10.5%, 11.9%, P < .001) but a similar risk of TSH greater than 5 mIU/L (odds ratio [OR] 1.44; 95% CI, 0.67-3.09, P = .35). The highest tertile also had a higher prevalence (6.2% vs 3.4%, 2.6%, P = .003) and risk (OR 1.72; 95% CI, 1.05-2.84, P = .008) of TSH greater than 10 mIU/L. Similar results were observed when comparing samples with nephrotic-range proteinuria (> 3.5g/day) to those with lesser proteinuria.

CONCLUSION

Hypothyroidism is common among adults with proteinuria, and the risk of hypothyroidism is directly related to the severity of proteinuria.

Thyroid function in patients with idiopathic nephrotic syndrome

BACKGROUND

Albumin is the major protein excreted in urine in patients with nephrotic syndrome (NS). However, low-molecular-weight proteins including some binding proteins are also excreted. Thyroid hormone and its binding globulins are excreted in urine in excess in nephrotic syndrome. Therefore, it has been postulated that patients with nephrotic syndrome may show hypothyroidism, subclinical or overt.

METHODS

In this prospective observational study, patients of idiopathic nephrotic syndrome aged 1-40 years of both gender were included. Serum T3, T4 and TSH were assayed at diagnosis and repeated at 12 weeks or at remission whichever was earlier. Renal biopsy was performed as required.

RESULTS

Among 100 patients taken for analysis (42 children, 58 adult), 30 cases were of first episode, 40 were of frequent relapse/steroid-dependent NS, and 30 patients had steroid-resistant NS (SRNS). Three (3%) cases had overt hypothyroidism and 18 (18%) patients had subclinical hypothyroidism. Most hypothyroid cases belonged to SRNS subgroup. Mean Serum T3, T4 and TSH values showed significant improvement in remission in comparison to nephrosis state (P < 0.01). Serum TSH had significant positive correlation (r = 0.391, P < 0.01) with 24-h proteinuria and negative correlation with serum albumin (r =  - 0.303, P < 0.01) in nephrosis.

CONCLUSION

Hypothyroidism is common among nephrotic syndrome patients especially in SRNS subgroup. Therefore, routine screening is recommended in steroid-resistant nephrotic syndrome patients.

IPNA clinical practice recommendations for the diagnosis and management of children with steroid-resistant nephrotic syndrome

Idiopathic nephrotic syndrome newly affects 1-3 per 100,000 children per year. Approximately 85% of cases show complete remission of proteinuria following glucocorticoid treatment. Patients who do not achieve complete remission within 4-6 weeks of glucocorticoid treatment have steroid-resistant nephrotic syndrome (SRNS). In 10-30% of steroid-resistant patients, mutations in podocyte-associated genes can be detected, whereas an undefined circulating factor of immune origin is assumed in the remaining ones. Diagnosis and management of SRNS is a great challenge due to its heterogeneous etiology, frequent lack of remission by further immunosuppressive treatment, and severe complications including the development of end-stage kidney disease and recurrence after renal transplantation. A team of experts including pediatric nephrologists and renal geneticists from the International Pediatric Nephrology Association (IPNA), a renal pathologist, and an adult nephrologist have now developed comprehensive clinical practice recommendations on the diagnosis and management of SRNS in children. The team performed a systematic literature review on 9 clinically relevant PICO (Patient or Population covered, Intervention, Comparator, Outcome) questions, formulated recommendations and formally graded them at a consensus meeting, with input from patient representatives and a dietician acting as external advisors and a voting panel of pediatric nephrologists. Research recommendations are also given.

Changes in the thyroid hormone profiles in children with nephrotic syndrome

Purpose

We compared thyroid hormone profiles in children with nephrotic syndrome (NS) during the nephrotic phase and after remission.

Methods

This study included 31 pediatric NS patients. The thyroid hormone profiles included serum levels of triiodothyronine (T3), thyroxine (T4), thyroid-stimulating hormone (TSH), and free T4.

Results

Of the 31 patients, 16 (51.6%) showed abnormal thyroid hormone profiles: 6 had overt hypothyroidism, 8 had subclinical hypothyroidism, and 2 had low T3 syndrome. The mean serum T3, T4, and free T4 levels in the nephrotic phase and after remission were 82.37±23.64 and 117.88±29.49 ng/dL, 5.47±1.14 and 7.91±1.56 µg/dL, and 1.02±0.26 and 1.38±0.23 ng/dL, respectively; the levels were significantly lower in the NS nephrotic phase (P=0.0007, P<0.0001, and P=0.0002). The mean serum TSH levels during the nephrotic phase and after remission were 8.05±3.53 and 4.08±2.05 µIU/ mL, respectively; they were significantly higher in the nephrotic phase (P=0.0005). The urinary protein/ creatinine ratio during the nephrotic phase was significantly correlated with serum T3, T4, and free T4 levels (r=-0.5995, P=0.0032; r=-0.5797, P=0.0047; r=-0.5513, P=0.0078) as well as with TSH levels (r=0.5022, P=0.0172). A significant correlation was found between serum albumin and serum T3 levels during the nephrotic phase (r=0.5385, P=0.0018) but not between serum albumin and T4, TSH, or free T4 levels. These significant correlations all disappeared after remission.

Conclusion

Abnormal thyroid hormone profile findings were observed in 51.6% of pediatric patients with NS. Thyroid hormone levels normalized after remission, regardless of levothyroxine therapy.

Non-Autoimmune Subclinical and Overt Hypothyroidism in Idiopathic Steroid-resistant Nephrotic Syndrome in Children

OBJECTIVE

To evaluate the frequency of non-autoimmune subclinical and overt hypothyroidism in children with idiopathic steroid-resistant nephrotic syndrome (SRNS).

METHODS

This cross-sectional study recruited 30 children (age 1-18 y) with idiopathic SRNS; and 30 healthy controls. Serum T3, T4 and TSH were performed in cases as well as controls. Anti-thyroid peroxidase and anti-thyroglobulin antibody tests were performed in all cases.

RESULTS

Non-autoimmune subclinical or overt hypothyroidism was detected in 10 out of 30 children with idiopathic SRNS; 2 had overt hypothyroidism, while 8 patients had subclinical hypothyroidism. Children with SRNS had a mean (SD) TSH value 4.55 (4.64) mIU/L that was higher as compared to controls (1.88 (1.04) mIU/L) (P<0.01). Focal segmental glomerulosclerosis (FSGS) was the commonest histopathological condition, seen in 13 (43.3%). Children with overt hypothyroidism (2 cases) and grade III subclinical hypothyroidism (1 case) were subsequently started on levothyroxine therapy.

CONCLUSION

The prevalence of subclinical and overt hypothyroidism seems to be high in idiopathic SRNS, with almost one-third of children having overt or subclinical non-autoimmune hypothyroidism.

A case of minimal change nephrotic syndrome with hypothyroidism deterioration

A 73-year-old woman with Graves' disease underwent total thyroidectomy and was being treated with levothyroxine. She developed edema in the lower region of both legs 1 month before hospitalization. She had a high concentration of urine protein and was hospitalized for further assessment. A urine protein concentration of 4.4 g/day was observed, and she was diagnosed with minimal change nephrotic syndrome (MCNS) after kidney biopsy. The patient's thyroid function had declined, as indicated by a thyroid-stimulating hormone (TSH) level of 139.0 μIU/mL and a free thyroxine (fT4) level of 0.66 ng/dL. She was prescribed 40 mg/day of prednisolone (PSL) and achieved remission. fT4 level normalized on the 36th hospital day. She was in remission subsequently. However, MCNS recurred when PSL was tapered to 10 mg/day. When she was rehospitalized, thyroid function decline was noted once more, with a TSH level of 29.8 μIU/mL and an fT4 level of 0.74 ng/dL. Her oral PSL dose was increased to 30 mg/day, but she did not achieve remission. However, she achieved remission after steroid pulse therapy. After remission, the thyroid function normalized. During the course of her treatment, the levothyroxine dose was maintained at 87.5 μg/day. Therefore, we predicted that the loss of thyroid hormone in urine due to nephrotic syndrome may have led to the aggravation of hypothyroidism. We have reported this case because of its rarity.

Do Not Forget Nephrotic Syndrome as a Cause of Increased Requirement of Levothyroxine Replacement Therapy

Nephrotic syndrome increases L-thyroxine requirements because of urinary loss of free and protein-bound thyroid hormones. We report 2 hypothyroid patients referred to us because of high serum TSH, even though the L-thyroxine daily dose was maintained at appropriate levels or was increased. The cause of nephrotic syndrome was multiple myeloma in one patient and diabetic glomerulosclerosis in the other patient. As part of the periodic controls for diabetes, urinalysis was requested only in the second patient so that proteinuria could be detected. However, as in the first patient, facial puffiness and body weight increase were initially attributed to hypothyroidism, which was poorly compensated by L-thyroxine therapy. In the first patient, the pitting nature of the pedal edema was missed at the initial examination. An endocrinologist consulted over the phone by the practitioner hypothesized some causes of intestinal malabsorption of L-thyroxine. This diagnosis would have been accepted had the patient continued taking a known sequestrant of L-thyroxine, i.e. calcium carbonate. The diagnostic workup of patients with increasing requirements of L-thyroxine replacement therapy should not be concentrated on the digestive system alone. Careful history taking and physical examination need to be thorough. Endocrinologists should not forget nephrotic syndrome that, in turn, can be secondary to serious diseases.

The nephrotic syndrome: pathogenesis and treatment of edema formation and secondary complications

Nephrotic syndrome is an important clinical condition affecting both children and adults. Studies suggest that the pathogenesis of edema in individual patients may occur via widely variable mechanisms, i.e., intravascular volume underfilling versus overfilling. Managing edema should therefore be directed to the underlying pathophysiology. Nephrotic syndrome is also associated with clinically important complications related to urinary loss of proteins other than albumin. This educational review focuses on the pathophysiology and management of edema and secondary complications in patients with nephrotic syndrome.