Table 3 Specific outcome parameters of studies

Baleeiro and Mull [32]³¹

Study design:

Case series

All have reported an improvement in symptoms and a decrease in sputum production and frequency of exacerbations

No other parameters measured

Cowan et al. [33]²⁹

Study Design:

Retrospective Case series

-Mean rate of moderate/severe AECOPD 0.64 (81% decrease, p = 0.0001)

- Mean rate of moderate AECOPD 0.57 (decrease 66.7%, p = 0.001)

- Mean rate of severe AECOPD 0.07 (decrease 46.4%, p = 0.016)

- 1 hospitalization—reduction of mild exacerbations also was present, but numbers not reported due to the subjective nature of the data

Changes in AECOPD events/patient-year stratified by GOLD[5] COPD stage and baseline IgG Moderate COPD (n = 7) pre: 5.14 ± 2.85, post: 0.86 ± 1.13

Severe/very severe COPD pre: 4.14 ± 2.95, post: 0.43 ± 0.5

No bronchiectasis (n = 6) pre: 4.00 ± 2.8, post: 0.83 ± 1.07

With bronchiectasis pre: 5.13 ± 2.93, post: 0.50 ± 0.71

IgG ≥ 5.9 g/L (n = 7) pre: 4.29 ± 3.33, post: 0.29 ± 0.45

IgG < 5.9 g/L pre: 5.00 ± 2.45, post: 1.00 ± 1.07

Adverse Events

Among n = 14, 1 had transfusion reaction to IVIG and 13 did not report any adverse reaction

Cowan et al. [35]³²

Study Design:

RCT

Study treatment adherence: 68.8 ± 5.7% (median: 85%) 18 patients (51.4%) adhered to 80% of their allocated treatment

Study control adherence: 59.4 ± 6.3% (median: 57%) 16 patients (45.7%) adhered to 80% of their allocated treatment

Study retention rate (treatment): 97.1% (n = 34). 1 withdrew consent. 3 died during the study period

Study retention rate (control): 91.4% (n = 32). 2 withdrew consent. 4 died during the study period

Intention-To-Treat (ITT):

Total number of AECOPD (number of patients with event): 56 (25) treated population & 48 (21) control population

Ratio rate (95% confidence intervals): 0.91(0.59–1.41)

AECOPD requiring hospitalization (n of patients with events): 16 (13) treated population & 20 (2) control population

Ratio rate (95% confidence intervals) 0.78 (0.37–1.65)

AECOPD requiring ED visits (n of patients with event): 12 (9) treated population & 2 (2) control population

Ratio rate (95% confidence intervals) 3.16 (0.64–15.60)

AECOPD managed as outpatients (n of patients with event): 28 (15) treated population & 26 (12) control population

Ratio rate (95% confidence intervals) 0.69 (0.37–1.30)

Per Protocol (PP):

Numbers of AECOPD (number of patients with event): 24 (12) treated population & 4 (3) control population

Ratio rate (95% confidence intervals): 0.98 (0.50–1.93)

AECOPD requiring hospitalization (n of patients with events): 4 (4) treated population & 4 (3) control population

Ratio rate (95% confidence intervals): 0.43 (0.07–2.49)

AECOPD requiring ED visits (n of patients with event): 5 (4) treated population & 1 (1) control population

Ratio rate (95% confidence intervals): 2.52 (0.23–27.7)

AECOPD managed as outpatients (n of patients with event): 15 (9) treated population & 19 (9) control population

Ratio rate (95% confidence intervals): 0.88 (0.39–1.97)

Adverse events (AE):

137 AE in 33 treated patients; Median (IQR): 2 (1–5)

126 AE in 27 control patients; Median (IQR): 3 (1–5)

(p = 0.55 compared to control)

Tolerability:

A higher number of patients continued to receive study treatment at week 48 in the IVIG group (58%) vs the control group (46%)

Treatment adherence for the treatment group was slightly better than the control group; however, no statistical analysis was done

McCullagh et al. ³⁰

Study Design:

Case series

Treatment Group:

PFT Results:

FVC, % (Range): 75.3 (57–93) after IVIG treatment (n = 4)

FEV1, % (Range): 51.4 (34–70) after IVIG treatment (n = 5)

FEV1/FVC, % (Range): 50.4 (27–69) after IVIG treatment (n = 5)

Outcome Parameters after Treatment:

Number of exacerbations per year (Range):

3.7 (2–6) (n = 7) before IVIG treatment and 1 (0–4) (n = 6) after IVIG treatment

Hospitalizations for AECOPD (Range):

2.3 (1–5) (n = 7) before IVIG treatment and 0.83 (0–4) (n = 6) after IVIG treatment

ICU admissions for AECOPD:

0.1 (0–1) (n = 7) before IVIG treatment and 0 (n = 6) after IVIG treatment

Average number courses of prednisone per year (Range):

6.9 (0–12) (n = 7) before IVIG treatment and 2.5 (0–12) (n = 6) after IVIG treatment

Average annual number courses of antibiotics (Range):

6.7 (3–12) (n = 7) before IVIG treatment and 8.67 (2–12) (n = 6) after IVIG treatment

Oxygen use (Range):

0.6 (0–1) (n = 7) before IVIG treatment and 0.6 (0–1) (n = 7) after IVIG treatment