A 56-year-old Caucasian man complained of recurrent bilateral lower extremity cellulitis and ulcerations, requiring hospitalization and parenteral antibiotic administration. History included factor V Leiden mutation with recurrent lower extremity deep venous thromboses and recurrent MRSA urinary tract infections. He had undergone numerous abdominal procedures, with recurrent enterocutaneous fistulae and wall abscesses. Abdominal exam revealed wall ulceration with serosanguineous drainage and surrounding erythema. His lower extremities presented ochre dermatitis, bilateral +/4 edema below the knee; there were 2 ulcerations on the anterior portion of his left leg, measuring 1 × 1 cm and 2 × 3 cm (Figure ). A lower extremity ultrasound showed a left-sided nonocclusive chronic thrombus in the femoral and popliteal veins. Total levels of immunoglobulins were normal (except for a small decrease in IgG3), as were C2 and C4 (Table ). Anticardiolipin antibody was negative. The patient had a low level of MBL (<50 ng/ml), genotyping showing a LYPB/LYPB polymorphism for MBL and a wild-type MASP-2 (Table ). The patient's abdominal wall culture grew cephalosporin-sensitive Staphylococcus aureus; cultures from his lower extremity ulcerations were positive for Pseudomonas aeruginosa. The patient responded to antimicrobials, compression stockings and topical Tacrolimus©.
A 39-year-old woman complained of recurrent pustular eruption of her upper extremities and chronic allergic rhinitis. Immunological evaluation demonstrated the following: IgG levels were slightly decreased, but IgG subclass levels were all normal. The patient had detectable/robust responses to 6/14 pneumococcal serotypes (Table ). Further work-up yielded a low level of MBL at < 50 ng/ml (reference: >100 ng/ml), as well as an impaired MBL pathway functional test using the C4b deposition assay. Genotyping showed the HYPD/HYPD variant of MBL2 and wild-type MASP-2 genotype (A/A) (Table ).