Inflammatory Back Pain and Psoriasis: Expecting Spondyloarthritis, Discovering Lymphoma.

Inflammatory back pain is a characteristic of spondyloarthritis. It is not, however, an exclusive symptom of inflammatory rheumatic diseases as it can also be associated with non-inflammatory entities. Infrequently, the etiology can be found in neoplastic conditions such as malignant lymphoma. Even in the presence of comorbidities indicatory of underlying rheumatic disease, like psoriasis vulgaris, the clinician should not be led astray. It is essential to pay attention to contradictory findings, as treatment crucially differs depending on diagnosis. Herein, we report on a psoriasis patient who presented with characteristic inflammatory back pain and deceptive imaging results. While the patient was initially thought to suffer from an inflammatory rheumatic disease with axial involvement, it was the accompanying atypical circumstances, particularly her age, that instantly challenged the diagnosis of axial psoriatic arthritis. She was eventually diagnosed with stage IV follicular lymphoma that manifested with rare and exclusively extranodal lesions and spondyloarthritis-like morphology. This case effectively demonstrates the importance of a thorough diagnostic workup and how certain clinical factors, such as the patient's age, should be considered when confronted with inflammatory back pain.

E-64c-Hydrazide Based Cathepsin C Inhibitors: Optimizing the Interactions with the S1'-S2' Area.

The zymogens of the neutrophil serine proteases elastase, proteinase 3, and cathepsin G are converted proteolytically into their pro-inflammatory active forms by the action of cathepsin C. The inhibition of this cysteine protease therefore is an interesting therapeutic approach for the treatment of inflammatory disorders with a high neutrophil burden such as COPD. Based on E-64c-hydrazide as lead structure, we have recently developed a covalently acting cathepsin C inhibitor using a n-butyl residue attached at the amine nitrogen of the hydrazide moiety to efficiently address the deep hydrophobic S2 pocket. To further optimize the affinity and selectivity profile of this inhibitor, the S1'-S2' area was now investigated by a combinatorial approach, showing that Nle-tryptamide is a ligand superior to the initially used Leu-isoamylamide. Using the neutrophil precursor line U937 as a cell culture model, this optimized inhibitor blocks the intracellular cathepsin C activity and thereby suppresses the activation of neutrophil elastase.

Spontaneous abortion as differential diagnosis of intermittent glomerular proteinuria in inactive systemic lupus erythematosus.

In women of childbearing age, severe proteinuria in systemic lupus erythematosus raises concern for renal involvement and pregnancy complications. While persisting renal loss of protein is known to culminate in extensive interventions, intermittent proteinuria in inactive disease requires an adjusted approach. Contextual awareness of this urinary finding is thus essential.