Analysis of frequency of pulmonary atelectasis in patients undergoing pectoralis major musculocutaneous flap reconstruction

Decreased CD57 expression of natural killer cells enhanced cytotoxicity in patients with primary sclerosing cholangitis

Background/aims

Primary sclerosing cholangitis (PSC) is a chronic inflammatory biliary disease for which the immunopathological basis remains an enigma. Natural killer (NK) cells are key components of innate immunity and seemingly play diversified roles in different autoimmune disorders (AIDs). The aim of this study was to determine the role of NK cells in the pathogenesis of PSC.

Methods

The frequency and phenotype of circulating NK cells in a large cohort of patients with PSC and healthy controls (HCs) were systematically examined. In addition, the functional capacity of NK cells including cytotoxicity and cytokine production was studied.

Results

The frequency of CD3⁻CD56^dimCD16⁺ (defined as CD56^dim) NK cells in PSC patients was significantly lower in comparison to HCs. CD56^dim NK cells from PSC displayed a more immature phenotype including high expression of the natural killing receptor NKp46 and downregulation of the highly differentiated NK cell marker CD57. Interestingly, the reduction of CD57 expression of NK cells was associated with the disease severity of PSC. In addition, PSC CD56^dim NK cells exhibited increased CD107a degranulation and cytolytic activity toward target cells compared with HCs. Further analysis demonstrated that CD57⁻CD56^dim NK cells from PSC had elevated expression of NKp46, NKp30, IL-2 receptor, and KLRG1 and higher cytotoxic capacity as compared to CD57⁺CD56^dim NK cells.

Conclusions

Our data demonstrate that the differentiation of PSC NK cells is dysregulated with enhanced cytotoxic activity. This change is likely to be functionally involved in pathogenesis and disease progression, deducing the potential of NK-directed immunotherapy for PSC.

Pulmonary function after pectoralis major myocutaneous flap harvest

OBJECTIVE

The pectoralis major myocutaneous flap is widely used in the reconstruction of surgical defects in the head and neck region. Pulmonary atelectasis has been reported in patients undergoing these procedures, and many of these patients are heavy smokers and drinkers and have associated cardiopulmonary disorders. Flap harvest and donor site closure may lead to impairment of pulmonary function before and after the use of pectoralis major myocutaneous (PMC) in surgical reconstruction in patients with cancer of the head and neck.

METHODS

Patients undergoing extirpation of head and neck tumors with PMC reconstruction were prospectively evaluated. Patient age, smoking history (pack-years), anesthesia duration, percentage predicted pre- and postoperative FEV1, percentage-predicted pre- and postoperative FVC (forced vital capacity), and preoperative SaO2 (oxygen saturation) were evaluated. Preoperative FEV1/FVC ratio was calculated. Chest x-rays were reviewed.

RESULTS

Only 11 patients, 5 of whom smoked, could be evaluated postoperatively. Preoperative FEV1/FVC was more than 70 and FEV1 more than 75% predicted in all patients. A decrease in FVC was observed in 7 of the 11 patients, which ranged between 2% and 27% without any clinically obvious respiratory manifestations. A baseline SaO2 of more than 96% was noted in all patients. Four of 9 postoperative chest x-rays demonstrated atelectasis.

CONCLUSIONS

PMC harvest and donor site closure may lead to the recorded decrease in FVC measurements. These changes did not manifest clinically. Nevertheless, alternative methods of surgical defect closure should be considered in patients with severe preexisting pulmonary disorders.