Discussion of the case
A young male of 28 years of age had arthritis of small and large joints with back pain for the past 10 months. He was also experiencing dry skin, weight gain, and marginal change in voice. Physical examination revealed no tender and swollen joints, and non-specific back pain. Investigations revealed moderately elevated CRP and normal ESR. Biochemistry findings indicate moderately elevated creatinine, no active sediments in urine, and elevated SGOT and SGPT. Viral serology and X-ray of hand/pelvis were normal. The patient was positive for ANA and negative for RF. The possible differential diagnoses are connective tissue disease (SLE and other related diseases), myositis, seronegative SpA, metabolic syndromes (hypothyroidism, renal disease, and myopathy), and infections secondary to hepatitis.
The musculoskeletal clinical features are mainly non-inflammatory. Since CRP is moderately high, it is necessary to consider the possibility of inflammatory arthritis. An increase in creatinine (an indicator of renal involvement) and SGOT/PT (indicates liver or muscle involvement) suggests a possible CTD. The skin changes can be explained by CTD. The presence of altered voice, weight gain, and skin changes suggest hypothyroidism, which may also explain elevated SGOT/PT, creatinine, and CRP. But they are normally seen in patients with prolonged, untreated hypothyroidism. Another possibility is an overlap of SSA (inflammatory arthritis) and hypothyroidism.
Considering the differential diagnoses, further, work-up should focus on thyroid function test, anti-TPO, anti-TG, ANA profiling, CPK, ultrasound examination of the abdomen for renal size, and liver parenchymal changes, and if required imaging of sacroiliitis.
ANA profiling of 12 antigens including extractable nuclear antigen, Ro, and SSA was negative. The results of other clinical investigations are as follows: CPK- 1350 IU, TSH> 100 IU, normal T3/ T4, and elevated anti-TPO and TG. Based on these findings, the diagnosis was concluded as hypothyroidism with myopathy.
Uncontrolled hypothyroidism explains the elevated levels of creatinine, SGOT, SGPT, CPK, and CRP, which are reversible.1 A paper published in 1977 has reported that the specific pattern of elevated CPK, SGOT, and LDH could be suggestive of hypothyroidism, especially in the presence of muscular symptoms.2, 3 The association of myopathy with chronic hypothyroidism could explain the occurrence of muscular pains, cramps, and mild to moderate weakness, it is also found during the short or acute clinical presentation. There is an increased chance of misdiagnosing hypothyroid patients as having polymyositis-like syndromes.4, 5 Muscle symptoms, such as aches and pain, stiffness, weakness, cramps, and hypertrophy, are mainly observed in hypothyroidism, and increased serum muscle enzyme values, particularly the level of CPK, indeed suggest polymyositis. Hypothyroid myopathy is associated with CPK values<5,000 U/l.6 Rhabdomyolysis is also reported, with elevated levels of creatinine and CPK.7
The present case typically fits into the description of Hashimoto thyroiditis with myopathy. Positive ANA is seen in 49% of patients with autoimmune thyroiditis.8 However, not all patients with positive ANA may develop the autoimmune rheumatic disease. Failure in reduces symptoms, even after the replacement of thyroxine, should raise the suspicion of overlap in such circumstances.9, 10
The most challenging aspect in the present case was the occurrence of non-specific musculoskeletal symptoms and elevated enzyme SGOT/PT, while the remaining LFT parameters were normal. Muscular involvement was confirmed by CPK testing and the final diagnosis by TFT.
Final diagnosis
Hashimoto thyroiditis with myopathy and minor acute renal compromise
Follow-up
The patient showed significant improvement in clinical symptoms following the replacement of thyroid hormone. Enzymes and creatinine resumed normal levels.
Learning points
- The thyroid metabolic syndrome may present with myopathy and altered renal function.
- The clinical signs of inflammation may not correlate with elevated CRP; hence it is important to consider other causes of elevated CRP
- Overlap of thyroid disorder with other autoimmune diseases is a possibility and it may be difficult to differentiate in certain cases.
References
- Gaede JT. Serum enzyme alterations in hypothyroidism before and after treatment. J Am Geriatr Soc. 1977 May;25(5):199–201.
- Mouzouri H, El Omri N, Sekkach Y, Frikh R, Nzambe C, Qacif H, et al. [Severe rhabdomyolysis revealing a myopathy linked to autoimmune hypothyroidism]. Ann Endocrinol (Paris). 2009 Mar;70(1):83–6.
- Kung AW, Ma JT, Yu YL, Wang CC, Woo EK, Lam KS, et al. Myopathy in acute hypothyroidism. Postgrad Med J. 1987 Aug;63(742):661–3.
- Toscano A, Bartolone S, Rodolico C, Migliorato A, Macaione V, La Rosa D, et al. Onset of hypothyroidism with polymyositis-like clinical features in elderly patients. Arch GerontolGeriatr. 1996;22Suppl 1:573–6.
- Ciompi ML, Zuccotti M, Bazzichi L, Puccetti L. Polymyositis-like syndrome in hypothyroidism: report of two cases. Thyroidology. 1994 Apr;6(1):33–6.
- Finsterer J, Stöllberger C, Grossegger C, Kroiss A. Hypothyroid myopathy with unusually high serum creatine kinase values. Horm Res. 1999;52(4):205–8.
- Joshi B, Jones D, Rochford A, Giblin L. Hypothyroidism and associated acute renal failure. J R Soc Med. 2009 May 1;102(5):199–200.
- Tektonidou MG, Anapliotou M, Vlachoyiannopoulos P, Moutsopoulos HM. Presence of systemic autoimmune disorders in patients with autoimmune thyroid diseases. Annals of the Rheumatic Diseases. 2004;63(9):1159–1161.
- Lazúrová I, Benhatchi K, Rovenský J, et al. Autoimmune thyroid disease and autoimmune rheumatic disorders: a two-sided analysis. Annals of the New York Academy of Sciences. 2009;1173:211–216.
