A 63-year-old woman presented with Raynaud's phenomenon and extensive cold-induced livedo reticularis. A skin biopsy showed no abnormality of the blood vessels but the blood contained high titres of a very unusual autoantibody against the M blood group, most active at low temperatures. An IgM cryoglobulin was detected, and anti-M activity was found in this fraction. The cells of the patient wer...

1 Brouet JC, Clauvel JP, Danon F, Klein M, Seligmann M. Biologic and clinical significance of cryoglobulins. A report of 86 cases. Am J Med 1974;57:775–88. 2 Romaszko JP, Tridon A, Jouanel P, Subtil E, Dibet P, Betail G. Détection et analyse des cryoglobulines: étude comparative d’une population de malades et d’une population de témoins sains. Pathol Biol (Paris) 1993;41: 525–9. 3 Tissot JD, Sp...

INTRODUCTION Laboratory tests play a central role in assessing a patient and orienting the diagnostic evaluation. We report a case where the discrepancy between the manual and automatic cell count gave a hint to the final diagnosis. CASE PRESENTATION A 55-year-old Caucasian man, known to have hepatitis C, was admitted with acute respiratory failure secondary to acute pulmonary edema and diffu...