Nephritis
May 11, 2025Combination therapy: ICI + TKI
May 13, 2025Muscle pathology
Polymyalgia rheumatica
- Typically inflammatory girdle (shoulder and pelvic) stiffness and pain
Management escalation pathway
- Diagnosis and treatment (corticoid therapy) can be done by oncologist/GP except when diagnosis is not clear or when there is lack of respons to corticoids (which suggests an alternative diagnosis)
- Corticoid treatment: 20 mg predni and tapering over 9-12 months (https://www.ncbi.nlm.nih.gov/pubmed/26352874)
Assessment and Investigations
- Blood sample: often elevated ESR/CRP (should be done before starting corticoids); CKs should be normal (in contrast to myositis)
- Check for symptoms of giant cell arteritis in order to avoid sudden blindness (discuss temporal artery biopsy with rheumatologist/internist)
Myositis
Symptom Grade 1
-
- Mild pain
- Mild muscle weakness
- CK value < 2,5 ULN
Symptom Grade 2
- Signs of muscle weakness
- Respiratory symptoms
- Swallowing problems (dysphagia)
- Diplopia possible
- CK > 2,5 ULN or elevated troponin
Management escalation pathway
- In case of doubt withhold ICPI Initiate paracetamol/NSAID
- If symptom severity increases despite NSAID consider treatment cfr grade 2 Control CK after one week, if increasing: discuss with local myositis specialist
Assessment and Investigations
- Complete history of all organ systems
- Perform examination of joints and skin
- Exclude cardiac origin (CKMB/troponin/pro-BNP and ECG) and in case of doubt perform cardiac MRI
- ! Troponin I is more specific of cardiac involvement than troponin T
- Exclude other causes of elevated CK: IM injection, physical activity, …
Management escalation pathway
- Stop ICPI
- Start corticoids 1mg/kg after discussion with internist/rhumatologist/neuromuscular specialist, continue for at least 1 month even if clinical imporvement after 1 week. If needed add other immunsuppressants so corticoids can be tapered after one month
- If no improvement after 48h (pain or CK): increase to 2 mg/kg; if still no improvement 48h later, other immunosuppressants should be discussed with experienced organ specialist
- Consider IVIG (no reimbursment in Belgium) or bolus steroids if severe life threatening weakness, less evidence for plasma exchange
Assessment and Investigations
- In addition to analysis for grade I:
1 - Perform EMG to evaluate myopathic features
2 - Assesment of diaphragm motion: X ray and perform respiratory tests both in upright and horizontal position.
- Perform MRI of affected muscle
- Consider muscle biopsy before start steroids (should be done by experienced specialist)
- Analyze serology before start of steroids (ANF (+further subanalysis), myositis specific antibodies / myositis associated antibodies: according to local practice)
- Perform spirometry in order to assess restrictive syndrom (due to paralysis of intercostal muscles)
Myastenia gravis
- Fluctuating muscle weakness (proximal limb, trunk, ocular, e.g. ptosis/diplopia or bulbar)
- Respiratory muscles may also be involved
Fatigability:
- Muscle weakness is induced and aggravated by exercise
Management escalation pathway
- Steroids indicated (oral or i.v.)
- Pyridostigmine initial dose 30 mg
- Neurological consult If no improvement, or worsening, plasmapheresis or IVIG may be considered
- Avoid certain medications, that may precipitate cholinergic crisis (e.g. ciprofloxacin, beta blockers, amikacin, benzodiazepines and above all curares during general anesthesia)’)
Assessment and Investigations
- Check for ocular muscle and proximal muscle fatigability AChr and MuSK antibodies
- Bedsides tests, e.g. Tensilon test or ice pack test with neurological input
- Repetitive nerve stimulation and single fibre EMG
- Exclude myocarditis with cardiac enzymes (and cardiac MRI in case of doubt) (cave pseudo myasthenic myositis)
In collaboration with
Rhumato-onco taskforce KBVR/SRBR (Yves Piette, Ellen Delanghe)
Gauthier Remiche, ULB Erasme
Olivier Lambotte, AP-HP, Hôpital Bicêtre, Service de Médecine Interne et Immunologie Clinique, Paris, France
Dimitri Psimaras, Praticien Hospitalier, Département de Neurologie Mazarin, GHPS, Paris, France
